Music has a fundamental affect on humans. It can reduce stress, enhance relaxation, provide a distraction from pain, and improve the results of clinical therapy. New research published in BioMed Central's open access journal Journal of Cardiothoracic Surgery demonstrates that music can reduce rejection of heart transplants in mice by influencing the immune system.
The link between the immune system and brain function is not clearly understood, nevertheless music is used clinically to reduce anxiety after heart attack, or to reduce pain and nausea during bone marrow transplantation. There is some evidence that music may act via the parasympathetic nervous system, which regulates the bodily functions that we have no conscious control over, including digestion.
Researchers from Japan investigated if music could influence the survival of heart transplants in mice. They found that opera and classical music both increased the time before the transplanted organs failed, but single frequency monotones and new age music did not.
The team led by Dr Masanori Niimi pinpointed the source of this protection to the spleen. Dr Uchiyama and Jin revealed, "Opera exposed mice had lower levels of interleukin-2 (IL-2) and interferon gamma (IFN-γ). They also had increased levels of anti-inflammatory IL-4 and IL-10. Significantly these mice had increased numbers of CD4+CD25+ cells, which regulate the peripheral immune response."
It seems that music really does influence the immune system -- although the mechanism behind this still is not clear. Additionally, this study only looked at a limited selection of composers, so the effect of music on reducing organ rejection may not be limited to opera.
Daytime Nap Can Benefit A Person's Memory Performance
A brief bout of non-REM sleep (45 minutes) obtained during a daytime nap clearly benefits a person's declarative memory performance, according to a new study.
The study, authored by Matthew A. Tucker, PhD, of the Center for Sleep and Cognition and the department of psychiatry at Harvard Medical School, focused on 33 subjects (11 males, 22 females) with an average age of 23.3 years. The participants arrived at the sleep lab at 11:30 a.m., were trained on each of the declarative memory tasks at 12:15 p.m., and at 1 p.m., 16 subjects took a nap while 17 remained awake in the lab. After the nap period, all subjects remained in the lab until the retest at 4 p.m.
It was discovered that, across three very different declarative memory tasks, a nap benefited performance compared to comparable periods of wakefulness, but only for those subjects that strongly acquired the tasks during the training session.
"These results suggest that there is a threshold acquisition level that has to be obtained for sleep to optimally process the memory," said Dr. Tucker. "The importance of this finding is that sleep may not indiscriminately process all information we acquire during wakefulness, only the information we learn well."
It is recommended that adults get between seven and eight hours of nightly sleep.
The article "Enhancement of Declarative Memory Performance Following a Daytime Nap is Contingent on Strength of Initial Task Acquisition" was published in the February 1 issue of the journal Sleep.
The study, authored by Matthew A. Tucker, PhD, of the Center for Sleep and Cognition and the department of psychiatry at Harvard Medical School, focused on 33 subjects (11 males, 22 females) with an average age of 23.3 years. The participants arrived at the sleep lab at 11:30 a.m., were trained on each of the declarative memory tasks at 12:15 p.m., and at 1 p.m., 16 subjects took a nap while 17 remained awake in the lab. After the nap period, all subjects remained in the lab until the retest at 4 p.m.
It was discovered that, across three very different declarative memory tasks, a nap benefited performance compared to comparable periods of wakefulness, but only for those subjects that strongly acquired the tasks during the training session.
"These results suggest that there is a threshold acquisition level that has to be obtained for sleep to optimally process the memory," said Dr. Tucker. "The importance of this finding is that sleep may not indiscriminately process all information we acquire during wakefulness, only the information we learn well."
It is recommended that adults get between seven and eight hours of nightly sleep.
The article "Enhancement of Declarative Memory Performance Following a Daytime Nap is Contingent on Strength of Initial Task Acquisition" was published in the February 1 issue of the journal Sleep.
Scientists Reprogram Cancer Cells With Low Doses of Epigenetic Drugs
Experimenting with cells in culture, researchers at the Johns Hopkins Kimmel Cancer Center have breathed possible new life into two drugs once considered too toxic for human cancer treatment. The drugs, azacitidine (AZA) and decitabine (DAC), are epigenetic-targeted drugs and work to correct cancer-causing alterations that modify DNA.
The researchers said the drugs also were found to take aim at a small but dangerous subpopulation of self-renewing cells, sometimes referred to as cancer stem cells, which evade most cancer drugs and cause recurrence and spread.
In a report published in the March 20, 2012, issue of Cancer Cell, the Johns Hopkins team said their study provides evidence that low doses of the drugs tested on cell cultures cause antitumor responses in breast, lung, and colon cancers.
Conventional chemotherapy agents work by indiscriminately poisoning and killing rapidly-dividing cells, including cancer cells, by damaging cellular machinery and DNA. "In contrast, low doses of AZA and DAC may re-activate genes that stop cancer growth without causing immediate cell-killing or DNA damage," says Stephen Baylin, M.D., Ludwig Professor of Oncology and deputy director of the Johns Hopkins Kimmel Cancer Center.
Many cancer experts had abandoned AZA and DAC for the treatment of common cancers, according to the researchers, because they are toxic to normal cells at standard high doses, and there was little research showing how they might work for cancer in general. Baylin and his colleague Cynthia Zahnow, Ph.D., decided to take another look at the drugs after low doses of the drugs showed a benefit in patients with a pre-leukemic disorder called myelodysplastic syndrome (MDS). Johns Hopkins investigators also showed benefit of low doses of the drugs in tests with a small number of advanced lung cancer patients. "This is contrary to the way we usually do things in cancer research," says Baylin, noting that "typically, we start in the laboratory and progress to clinical trials. In this case, we saw results in clinical trials that made us go back to the laboratory to figure out how to move the therapy forward."
For the research, Baylin and Zahnow's team worked with leukemia, breast, and other cancer cell lines and human tumor samples using the lowest possible doses that were effective against the cancers. In all, the investigators studied six leukemia cell lines, seven leukemia patient samples, three breast cancer cell lines, seven breast tumor samples (including four samples of tumors that had spread to the lung), one lung cancer tumor sample, and one colon cancer tumor sample. The team treated cell lines and tumor cells with low-dose AZA and DAC in culture for three days and allowed the drug-treated cells to rest for a week. Treated cells and tumor samples were then transplanted into mice where the researchers observed continued antitumor responses for up to 20 weeks. This extended response was in line with observations in some MDS patients who continued to have anticancer effects long after stopping the drug.
The low-dose therapy reversed cancer cell gene pathways, including those controlling cell cycle, cell repair, cell maturation, cell differentiation, immune cell interaction, and cell death. Effects varied among individual tumor cells, but the scientists generally saw that cancer cells reverted to a more normal state and eventually died. These results were caused, in part, by alteration of the epigenetic, or chemical environment, of DNA. Epigenetic activities turn on certain genes and block others, says Zahnow, assistant professor of oncology and the Evelyn Grolman Glick Scholar at Johns Hopkins.
The research team also tested AZA and DAC's effect on a type of metastatic breast cancer cell thought to drive cancer growth and resist standard therapies. Metastatic cells are difficult to study in standard laboratory tumor models, because they tend to break away from the original tumor and float around in blood and lymph fluids. The Johns Hopkins team re-created the metastatic stem cells' environment, allowing them to grow as floating spheres. "These cells were growing well as spheres in suspension, but when we treated the cells with AZA, both the size and number of spheres were dramatically reduced," says Zahnow.
The precise mechanism of how the drugs work is the focus of ongoing studies by Baylin and his team. "Our findings match evidence from recent clinical trials suggesting that the drugs shrink tumors more slowly over time as they repair altered mechanisms in cells and genes return to normal function and the cells may eventually die," says Baylin.
The results of clinical trials in lung cancer, led by Johns Hopkins' Charles Rudin, M.D., and published late last year in Cancer Discovery, also indicate that the drugs make tumors more responsive to standard anticancer drug treatment. This means, they say, that the drugs could become part of a combined treatment approach rather than a stand-alone therapy and as part of personalized approaches in patients whose cancers fit specific epigenetic and genetic profiles.
Low doses of both drugs are approved by the U.S. Food and Drug Administration for the treatment of MDS and chronic myelomonocytic leukemia (CMML). Clinical trials in breast and lung cancer have begun in patients with advanced disease, and trials in colon cancer are planned.
In addition to Baylin and Zahnow, other investigators participating in this study include Hsing-Chen Tsai, Huili Li, Leander Van Neste, Yi Cai, Carine Robert, Feyruz V. Rassool, James J. Shin, Kirsten M. Harbom, Robert Beaty, Emmanouil Pappou, James Harris, Ray-Whay Chiu Yen, Nita Ahuja, Malcolm V. Brock, Vered Stearns, David Feller-Kopman, Lonny B. Yarmus, Yi-Chun Lin, Alana L. Welm, Jean-Pierre Issa, Il Minn, William Matsui, Yoon-Young Jang, and Saul J. Sharkis.
The researchers said the drugs also were found to take aim at a small but dangerous subpopulation of self-renewing cells, sometimes referred to as cancer stem cells, which evade most cancer drugs and cause recurrence and spread.
In a report published in the March 20, 2012, issue of Cancer Cell, the Johns Hopkins team said their study provides evidence that low doses of the drugs tested on cell cultures cause antitumor responses in breast, lung, and colon cancers.
Conventional chemotherapy agents work by indiscriminately poisoning and killing rapidly-dividing cells, including cancer cells, by damaging cellular machinery and DNA. "In contrast, low doses of AZA and DAC may re-activate genes that stop cancer growth without causing immediate cell-killing or DNA damage," says Stephen Baylin, M.D., Ludwig Professor of Oncology and deputy director of the Johns Hopkins Kimmel Cancer Center.
Many cancer experts had abandoned AZA and DAC for the treatment of common cancers, according to the researchers, because they are toxic to normal cells at standard high doses, and there was little research showing how they might work for cancer in general. Baylin and his colleague Cynthia Zahnow, Ph.D., decided to take another look at the drugs after low doses of the drugs showed a benefit in patients with a pre-leukemic disorder called myelodysplastic syndrome (MDS). Johns Hopkins investigators also showed benefit of low doses of the drugs in tests with a small number of advanced lung cancer patients. "This is contrary to the way we usually do things in cancer research," says Baylin, noting that "typically, we start in the laboratory and progress to clinical trials. In this case, we saw results in clinical trials that made us go back to the laboratory to figure out how to move the therapy forward."
For the research, Baylin and Zahnow's team worked with leukemia, breast, and other cancer cell lines and human tumor samples using the lowest possible doses that were effective against the cancers. In all, the investigators studied six leukemia cell lines, seven leukemia patient samples, three breast cancer cell lines, seven breast tumor samples (including four samples of tumors that had spread to the lung), one lung cancer tumor sample, and one colon cancer tumor sample. The team treated cell lines and tumor cells with low-dose AZA and DAC in culture for three days and allowed the drug-treated cells to rest for a week. Treated cells and tumor samples were then transplanted into mice where the researchers observed continued antitumor responses for up to 20 weeks. This extended response was in line with observations in some MDS patients who continued to have anticancer effects long after stopping the drug.
The low-dose therapy reversed cancer cell gene pathways, including those controlling cell cycle, cell repair, cell maturation, cell differentiation, immune cell interaction, and cell death. Effects varied among individual tumor cells, but the scientists generally saw that cancer cells reverted to a more normal state and eventually died. These results were caused, in part, by alteration of the epigenetic, or chemical environment, of DNA. Epigenetic activities turn on certain genes and block others, says Zahnow, assistant professor of oncology and the Evelyn Grolman Glick Scholar at Johns Hopkins.
The research team also tested AZA and DAC's effect on a type of metastatic breast cancer cell thought to drive cancer growth and resist standard therapies. Metastatic cells are difficult to study in standard laboratory tumor models, because they tend to break away from the original tumor and float around in blood and lymph fluids. The Johns Hopkins team re-created the metastatic stem cells' environment, allowing them to grow as floating spheres. "These cells were growing well as spheres in suspension, but when we treated the cells with AZA, both the size and number of spheres were dramatically reduced," says Zahnow.
The precise mechanism of how the drugs work is the focus of ongoing studies by Baylin and his team. "Our findings match evidence from recent clinical trials suggesting that the drugs shrink tumors more slowly over time as they repair altered mechanisms in cells and genes return to normal function and the cells may eventually die," says Baylin.
The results of clinical trials in lung cancer, led by Johns Hopkins' Charles Rudin, M.D., and published late last year in Cancer Discovery, also indicate that the drugs make tumors more responsive to standard anticancer drug treatment. This means, they say, that the drugs could become part of a combined treatment approach rather than a stand-alone therapy and as part of personalized approaches in patients whose cancers fit specific epigenetic and genetic profiles.
Low doses of both drugs are approved by the U.S. Food and Drug Administration for the treatment of MDS and chronic myelomonocytic leukemia (CMML). Clinical trials in breast and lung cancer have begun in patients with advanced disease, and trials in colon cancer are planned.
In addition to Baylin and Zahnow, other investigators participating in this study include Hsing-Chen Tsai, Huili Li, Leander Van Neste, Yi Cai, Carine Robert, Feyruz V. Rassool, James J. Shin, Kirsten M. Harbom, Robert Beaty, Emmanouil Pappou, James Harris, Ray-Whay Chiu Yen, Nita Ahuja, Malcolm V. Brock, Vered Stearns, David Feller-Kopman, Lonny B. Yarmus, Yi-Chun Lin, Alana L. Welm, Jean-Pierre Issa, Il Minn, William Matsui, Yoon-Young Jang, and Saul J. Sharkis.
Sleep Helps Reduce Errors In Memory, Research Suggests
Sleep may reduce mistakes in memory, according to a first-of-its-kind study led by a cognitive neuroscientist at Michigan State University.
See Also:
Health & Medicine
Sleep Disorder Research
Insomnia Research
Alzheimer's Research
Mind & Brain
Memory
Sleep Disorders
Insomnia
Reference
Memory bias
Sleep deprivation
Circadian rhythm sleep disorder
Rapid eye movement
The findings, which appear in the September issue of the journal Learning & Memory, have practical implications for everyone from students flubbing multiple choice tests to senior citizens confusing their medications, said Kimberly Fenn, principal investigator and MSU assistant professor of psychology.
“It’s easy to muddle things in your mind,” Fenn said. “This research suggests that after sleep you’re better able to tease apart the incorrect aspect of that memory.”
Fenn and colleagues from the University of Chicago and Washington University in St. Louis studied the presence of false memory in groups of college students. While previous research has shown that sleep improves memory, this study is the first to address errors in memory, she said.
Study participants were exposed to lists of words and then, 12 hours later, exposed to individual words and asked to identify which words they had seen or heard in the earlier session. One group of students was trained in the morning (10 a.m.) and tested after the course of a normal sleepless day (10 p.m.), while another group was trained at night and tested 12 hours later in the morning, after at least six hours of sleep.
Three experiments were conducted, using different stimuli. In each, the students who had slept had fewer problems with false memory – choosing fewer incorrect words.
How does sleep help? The answer isn’t known, Fenn said, but she suspects it may be due to sleep strengthening the source of the memory. The source, or context in which the information is acquired, is a vital element of the memory process.
Or perhaps the people who didn’t sleep during the study were simply bombarded with information over the course of the day, affecting their memory ability, Fenn said.
Further research is warranted, she said, adding that she plans to study different population groups, particularly the elderly.
“We know older individuals generally have worse memory performance than younger individuals. We also know from other research that elderly individuals tend to be more prone to false memories,” Fenn said. “Given the work we’ve done it’s possible that sleep may actually help them to reject this false information. And potentially this could help to improve their quality of life in some way.”
See Also:
Health & Medicine
Sleep Disorder Research
Insomnia Research
Alzheimer's Research
Mind & Brain
Memory
Sleep Disorders
Insomnia
Reference
Memory bias
Sleep deprivation
Circadian rhythm sleep disorder
Rapid eye movement
The findings, which appear in the September issue of the journal Learning & Memory, have practical implications for everyone from students flubbing multiple choice tests to senior citizens confusing their medications, said Kimberly Fenn, principal investigator and MSU assistant professor of psychology.
“It’s easy to muddle things in your mind,” Fenn said. “This research suggests that after sleep you’re better able to tease apart the incorrect aspect of that memory.”
Fenn and colleagues from the University of Chicago and Washington University in St. Louis studied the presence of false memory in groups of college students. While previous research has shown that sleep improves memory, this study is the first to address errors in memory, she said.
Study participants were exposed to lists of words and then, 12 hours later, exposed to individual words and asked to identify which words they had seen or heard in the earlier session. One group of students was trained in the morning (10 a.m.) and tested after the course of a normal sleepless day (10 p.m.), while another group was trained at night and tested 12 hours later in the morning, after at least six hours of sleep.
Three experiments were conducted, using different stimuli. In each, the students who had slept had fewer problems with false memory – choosing fewer incorrect words.
How does sleep help? The answer isn’t known, Fenn said, but she suspects it may be due to sleep strengthening the source of the memory. The source, or context in which the information is acquired, is a vital element of the memory process.
Or perhaps the people who didn’t sleep during the study were simply bombarded with information over the course of the day, affecting their memory ability, Fenn said.
Further research is warranted, she said, adding that she plans to study different population groups, particularly the elderly.
“We know older individuals generally have worse memory performance than younger individuals. We also know from other research that elderly individuals tend to be more prone to false memories,” Fenn said. “Given the work we’ve done it’s possible that sleep may actually help them to reject this false information. And potentially this could help to improve their quality of life in some way.”
Meditation Can Lower Blood Pressure, Study Shows
Transcendental Meditation is an effective treatment for controlling high blood pressure with the added benefit of bypassing possible side effects and hazards of anti-hypertension drugs, according to a new meta-analysis conducted at the University of Kentucky.
The meta-analysis evaluated nine randomized, controlled trials using Transcendental Meditation as a primary intervention for hypertensive patients. The practice of Transcendental Meditation was associated with approximate reductions of 4.7 mm systolic blood pressure and 3.2 mm diastolic blood pressure.
The study's lead author, Dr. James W. Anderson, professor of medicine at the University of Kentucky College of Medicine, said that blood pressure reductions of this magnitude would be expected to be accompanied by significant reductions in risk for atherosclerotic cardiovascular disease—without drug side effects. Anderson's most recent findings reinforce an earlier study that found Transcendental Meditation produces a statistically significant reduction in high blood pressure that was not found with other forms of relaxation, meditation, biofeedback or stress management.
"Adding Transcendental Medication is about equivalent to adding a second antihypertension agent to one's current regimen only safer and less troublesome," Anderson said.
The Centers for Disease Control and Prevention (CDC) estimates that 1 out of 3 American adults have high blood pressure. Having high blood pressure increases one's chances of developing heart disease, stroke, congestive heart failure and kidney disease.
The study appears in the March issue of the American Journal of Hypertension.
The meta-analysis evaluated nine randomized, controlled trials using Transcendental Meditation as a primary intervention for hypertensive patients. The practice of Transcendental Meditation was associated with approximate reductions of 4.7 mm systolic blood pressure and 3.2 mm diastolic blood pressure.
The study's lead author, Dr. James W. Anderson, professor of medicine at the University of Kentucky College of Medicine, said that blood pressure reductions of this magnitude would be expected to be accompanied by significant reductions in risk for atherosclerotic cardiovascular disease—without drug side effects. Anderson's most recent findings reinforce an earlier study that found Transcendental Meditation produces a statistically significant reduction in high blood pressure that was not found with other forms of relaxation, meditation, biofeedback or stress management.
"Adding Transcendental Medication is about equivalent to adding a second antihypertension agent to one's current regimen only safer and less troublesome," Anderson said.
The Centers for Disease Control and Prevention (CDC) estimates that 1 out of 3 American adults have high blood pressure. Having high blood pressure increases one's chances of developing heart disease, stroke, congestive heart failure and kidney disease.
The study appears in the March issue of the American Journal of Hypertension.
Memory Links to 40 Winks
When it comes to executing items on tomorrow's to-do list, it's best to think it over, then "sleep on it," say psychologists at Washington University in St. Louis.
People who sleep after processing and storing a memory carry out their intentions much better than people who try to execute their plan before getting to sleep. The researchers have shown that sleep enhances our ability to remember to do something in the future, a skill known as prospective memory.
Moreover, researchers studying the relationship between memory and sleep say that our ability to carry out our intentions is not so much a function of how firmly that intention has been embedded in our memories. Rather, the trigger that helps carry out our intentions is usually a place, situation or circumstance -- some context encountered the next day -- that sparks the recall of an intended action.
These are the key findings from a study published online this month in Psychological Science of the relationship between memory and sleep. Researchers Michael Scullin, doctoral candidate in psychology, and his adviser, Mark McDaniel, PhD, professor of psychology in Arts & Sciences, are focusing on "prospective memory" -- things we intend to do -- as opposed to "retrospective memory" -- things that have happened in the past.
Prospective memory includes such things as remembering to take a medication, buying a Mother's Day card or bringing home the ice cream for a birthday party. While the vast majority of sleep literature in psychology is devoted to retrospective memory, this study is the first foray into the relationship between sleep and prospective memory, the kind of memory we put to work every day. The findings, researchers say, offer important contributions to the understanding of the role sleep plays in cognition as well as memory.
Let's say that you intend to give a colleague a message tomorrow, McDaniel explains. Seeing the colleague the next day will be a strong cue for remembering to give the message. But, during the time your brain encoded the intention, you're also vaguely thinking of a meeting the two of you will attend the next afternoon. The context of the conference room is weakly associated with your intention to give the message even though you haven't really thought explicitly about associating the room with the message.
The Scullin/McDaniel study shows that sleep strengthens the weak association between the conference room (the context) and the delivery of the message (the intention). But sleep does little or nothing with the stronger association between the person and the message.
"We found that sleep benefits prospective memory by strengthening the weak associations in the brain, and that hasn't been shown before," Scullin says.
"One of the more provocative findings we have is that sleep didn't strengthen the link between the explicit cue, which is the person, and the intention, rather it strengthened the weak association and the intention," McDaniel says.
Here's how they showed it:
The researchers tested four different groups each of 24 Washington University students. Two were control groups -- one tested in the morning, the other in the evening -- to eliminate the notion that the biological clock might play any role in memory function. Another group was prepped for tests in the morning then tested twelve hours later in the evening before getting to sleep. The fourth group learned the test routine in the evening, went home and slept, then were tested 12 hours later in the morning.
Participants were given instructions for three tests in this order and the tests later were given in blocks of 150 items in the same order: a living/non-living test, in which they decided if a word (cat, for instance, or skate) indicated a living or non-living entity; a lexical decision test, in which participants decided if a string of letters was a word or nonsense; and a semantic category test, in which a word was classified by participants into a category, baseball, for instance, in the category of sport.
After learning the last test, participants were told that in the midst of these ongoing tests -- given to represent such everyday activities as driving, watching TV, listening to a teacher -- the words table or horse would pop up on a screen, and when they saw them, they were to press the "Q" button. This represented the prospective memory intention.
The researchers found that participants who tested in the morning following sleep overwhelmingly performed the prospective memory task better in the semantic category test, or context, than in the other two, and they found no such correlation in the group who tested sleepless.
The crux of the finding rests on the fact that the prospective memory instruction was given right after the semantic category practice. In this context, those who slept remembered the prospective memory intention better than in the other categories.
"Sleep promoted the remembering to do the prospective memory task when that one context was present, but not when some other context was present," McDaniel says. "That's because of temporal contiguity -- the fact that the participants were told to hit that 'Q' button right after they were exposed to the semantic category context.
"The idea is that the semantic category test is weakly associated with the prospective memory intention -- it's weakly floating around in the mind and becomes weakly associated with the prospective memory test," McDaniel says.
To return to the colleague and message analogy, because before sleeping you remembered you had a message to deliver to your colleague and you would see him in the conference room tomorrow, sleep enhances the likelihood that you will tell him in the conference room, but not in some other context, the office, elevator, the mail room, for example.
The researchers believe that the prospective memory process occurs during slow wave sleep -- an early pattern in the sleep cycle -- involving communication between the hippocampus and cortical regions. The hippocampus is very important in memory formation and reactivation and the cortical regions are keys to storing memories.
"We think that during slow wave sleep the hippocampus is reactivating these recently learned memories, taking them up and placing them in long-term storage regions in the brain," Scullin says. "The physiology of slow wave sleep seems very conducive to this kind of memory strengthening."
People who sleep after processing and storing a memory carry out their intentions much better than people who try to execute their plan before getting to sleep. The researchers have shown that sleep enhances our ability to remember to do something in the future, a skill known as prospective memory.
Moreover, researchers studying the relationship between memory and sleep say that our ability to carry out our intentions is not so much a function of how firmly that intention has been embedded in our memories. Rather, the trigger that helps carry out our intentions is usually a place, situation or circumstance -- some context encountered the next day -- that sparks the recall of an intended action.
These are the key findings from a study published online this month in Psychological Science of the relationship between memory and sleep. Researchers Michael Scullin, doctoral candidate in psychology, and his adviser, Mark McDaniel, PhD, professor of psychology in Arts & Sciences, are focusing on "prospective memory" -- things we intend to do -- as opposed to "retrospective memory" -- things that have happened in the past.
Prospective memory includes such things as remembering to take a medication, buying a Mother's Day card or bringing home the ice cream for a birthday party. While the vast majority of sleep literature in psychology is devoted to retrospective memory, this study is the first foray into the relationship between sleep and prospective memory, the kind of memory we put to work every day. The findings, researchers say, offer important contributions to the understanding of the role sleep plays in cognition as well as memory.
Let's say that you intend to give a colleague a message tomorrow, McDaniel explains. Seeing the colleague the next day will be a strong cue for remembering to give the message. But, during the time your brain encoded the intention, you're also vaguely thinking of a meeting the two of you will attend the next afternoon. The context of the conference room is weakly associated with your intention to give the message even though you haven't really thought explicitly about associating the room with the message.
The Scullin/McDaniel study shows that sleep strengthens the weak association between the conference room (the context) and the delivery of the message (the intention). But sleep does little or nothing with the stronger association between the person and the message.
"We found that sleep benefits prospective memory by strengthening the weak associations in the brain, and that hasn't been shown before," Scullin says.
"One of the more provocative findings we have is that sleep didn't strengthen the link between the explicit cue, which is the person, and the intention, rather it strengthened the weak association and the intention," McDaniel says.
Here's how they showed it:
The researchers tested four different groups each of 24 Washington University students. Two were control groups -- one tested in the morning, the other in the evening -- to eliminate the notion that the biological clock might play any role in memory function. Another group was prepped for tests in the morning then tested twelve hours later in the evening before getting to sleep. The fourth group learned the test routine in the evening, went home and slept, then were tested 12 hours later in the morning.
Participants were given instructions for three tests in this order and the tests later were given in blocks of 150 items in the same order: a living/non-living test, in which they decided if a word (cat, for instance, or skate) indicated a living or non-living entity; a lexical decision test, in which participants decided if a string of letters was a word or nonsense; and a semantic category test, in which a word was classified by participants into a category, baseball, for instance, in the category of sport.
After learning the last test, participants were told that in the midst of these ongoing tests -- given to represent such everyday activities as driving, watching TV, listening to a teacher -- the words table or horse would pop up on a screen, and when they saw them, they were to press the "Q" button. This represented the prospective memory intention.
The researchers found that participants who tested in the morning following sleep overwhelmingly performed the prospective memory task better in the semantic category test, or context, than in the other two, and they found no such correlation in the group who tested sleepless.
The crux of the finding rests on the fact that the prospective memory instruction was given right after the semantic category practice. In this context, those who slept remembered the prospective memory intention better than in the other categories.
"Sleep promoted the remembering to do the prospective memory task when that one context was present, but not when some other context was present," McDaniel says. "That's because of temporal contiguity -- the fact that the participants were told to hit that 'Q' button right after they were exposed to the semantic category context.
"The idea is that the semantic category test is weakly associated with the prospective memory intention -- it's weakly floating around in the mind and becomes weakly associated with the prospective memory test," McDaniel says.
To return to the colleague and message analogy, because before sleeping you remembered you had a message to deliver to your colleague and you would see him in the conference room tomorrow, sleep enhances the likelihood that you will tell him in the conference room, but not in some other context, the office, elevator, the mail room, for example.
The researchers believe that the prospective memory process occurs during slow wave sleep -- an early pattern in the sleep cycle -- involving communication between the hippocampus and cortical regions. The hippocampus is very important in memory formation and reactivation and the cortical regions are keys to storing memories.
"We think that during slow wave sleep the hippocampus is reactivating these recently learned memories, taking them up and placing them in long-term storage regions in the brain," Scullin says. "The physiology of slow wave sleep seems very conducive to this kind of memory strengthening."
Sleep Apnea Patients Have Greatly Increased Risk Of Severe Car Crashes
People with obstructive sleep apnea have a markedly increased risk of severe motor vehicle crashes involving personal injury, according to a new study.
The study of 800 people with sleep apnea and 800 without the nighttime breathing disorder found that patients with sleep apnea were twice as likely as people without sleep apnea to have a car crash, and three to five times as likely to have a serious crash involving personal injury. Overall, the sleep apnea group had a total of 250 crashes over three years, compared with 123 crashes in the group without sleep apnea.
While many previous studies have shown that sleep apnea patients are at increased risk of car crashes, this study is the first to look at the severity of those crashes. "We were surprised not only about how many of the sleep apnea patients' crashes involved personal injury, but that some patients had fairly mild sleep apnea and were still having serious crashes," says Alan Mulgrew, M.D., of the UBC Sleep Disorders Program in Vancouver, British Columbia.
Patients' self-reported feeling of sleepiness was not found to be linked with an increased risk of car crashes, suggesting that patients are unaware of their driving hazard, Dr. Mulgrew says. Even patients with fairly mild sleep apnea were at increased risk of car crashes. "Based on these findings, I now consider driving risk when deciding on treatment for patients with mild sleep apnea," he says.
The study is the biggest one to combine validated sleep apnea diagnosis through an overnight sleep study called polysomnography, with data from insurance records to verify motor vehicle crashes and their severity.
In obstructive sleep apnea, the upper airway narrows, or collapses, during sleep. Periods of apnea end with a brief partial arousal that may disrupt sleep hundreds of times a night. Obesity is a major risk factor for sleep apnea.
The study found that while in the general population men have more vehicle crashes than women, among sleep apnea patients, men and women crash at a similar rate.
Although the issue of treatment is not addressed by this study, Dr. Mulgrew notes that data from other groups suggests that crashes related to sleep apnea are preventable.
This research was presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20. "Severity of Motor Vehicle Crashes in Obstructive Sleep Apnea Patients"
The study of 800 people with sleep apnea and 800 without the nighttime breathing disorder found that patients with sleep apnea were twice as likely as people without sleep apnea to have a car crash, and three to five times as likely to have a serious crash involving personal injury. Overall, the sleep apnea group had a total of 250 crashes over three years, compared with 123 crashes in the group without sleep apnea.
While many previous studies have shown that sleep apnea patients are at increased risk of car crashes, this study is the first to look at the severity of those crashes. "We were surprised not only about how many of the sleep apnea patients' crashes involved personal injury, but that some patients had fairly mild sleep apnea and were still having serious crashes," says Alan Mulgrew, M.D., of the UBC Sleep Disorders Program in Vancouver, British Columbia.
Patients' self-reported feeling of sleepiness was not found to be linked with an increased risk of car crashes, suggesting that patients are unaware of their driving hazard, Dr. Mulgrew says. Even patients with fairly mild sleep apnea were at increased risk of car crashes. "Based on these findings, I now consider driving risk when deciding on treatment for patients with mild sleep apnea," he says.
The study is the biggest one to combine validated sleep apnea diagnosis through an overnight sleep study called polysomnography, with data from insurance records to verify motor vehicle crashes and their severity.
In obstructive sleep apnea, the upper airway narrows, or collapses, during sleep. Periods of apnea end with a brief partial arousal that may disrupt sleep hundreds of times a night. Obesity is a major risk factor for sleep apnea.
The study found that while in the general population men have more vehicle crashes than women, among sleep apnea patients, men and women crash at a similar rate.
Although the issue of treatment is not addressed by this study, Dr. Mulgrew notes that data from other groups suggests that crashes related to sleep apnea are preventable.
This research was presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20. "Severity of Motor Vehicle Crashes in Obstructive Sleep Apnea Patients"
Sleep Makes Your Memories Stronger, and Helps With Creativity
As humans, we spend about a third of our lives asleep. So there must be a point to it, right? Scientists have found that sleep helps consolidate memories, fixing them in the brain so we can retrieve them later. Now, new research is showing that sleep also seems to reorganize memories, picking out the emotional details and reconfiguring the memories to help you produce new and creative ideas, according to the authors of an article in Current Directions in Psychological Science.
"Sleep is making memories stronger," says Jessica D. Payne of the University of Notre Dame, who co-wrote the review with Elizabeth A. Kensinger of Boston College. "It also seems to be doing something which I think is so much more interesting, and that is reorganizing and restructuring memories."
Payne and Kensinger study what happens to memories during sleep, and they have found that a person tends to hang on to the most emotional part of a memory. For example, if someone is shown a scene with an emotional object, such as a wrecked car, in the foreground, they're more likely to remember the emotional object than, say, the palm trees in the background -- particularly if they're tested after a night of sleep. They have also measured brain activity during sleep and found that regions of the brain involved with emotion and memory consolidation are active.
"In our fast-paced society, one of the first things to go is our sleep," Payne says. "I think that's based on a profound misunderstanding that the sleeping brain isn't doing anything." The brain is busy. It's not just consolidating memories, it's organizing them and picking out the most salient information. She thinks this is what makes it possible for people to come up with creative, new ideas.
Payne has taken the research to heart. "I give myself an eight-hour sleep opportunity every night. I never used to do that -- until I started seeing my data," she says. People who say they'll sleep when they're dead are sacrificing their ability to have good thoughts now, she says. "We can get away with less sleep, but it has a profound effect on our cognitive abilities."
"Sleep is making memories stronger," says Jessica D. Payne of the University of Notre Dame, who co-wrote the review with Elizabeth A. Kensinger of Boston College. "It also seems to be doing something which I think is so much more interesting, and that is reorganizing and restructuring memories."
Payne and Kensinger study what happens to memories during sleep, and they have found that a person tends to hang on to the most emotional part of a memory. For example, if someone is shown a scene with an emotional object, such as a wrecked car, in the foreground, they're more likely to remember the emotional object than, say, the palm trees in the background -- particularly if they're tested after a night of sleep. They have also measured brain activity during sleep and found that regions of the brain involved with emotion and memory consolidation are active.
"In our fast-paced society, one of the first things to go is our sleep," Payne says. "I think that's based on a profound misunderstanding that the sleeping brain isn't doing anything." The brain is busy. It's not just consolidating memories, it's organizing them and picking out the most salient information. She thinks this is what makes it possible for people to come up with creative, new ideas.
Payne has taken the research to heart. "I give myself an eight-hour sleep opportunity every night. I never used to do that -- until I started seeing my data," she says. People who say they'll sleep when they're dead are sacrificing their ability to have good thoughts now, she says. "We can get away with less sleep, but it has a profound effect on our cognitive abilities."
Meditation May Be An Effective Treatment For Insomnia
Meditation may be an effective behavioral intervention in the treatment of insomnia, according to a research abstract that will be presented on June 9, at Sleep 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies.
Results indicate that patients saw improvements in subjective sleep quality and sleep diary parameters while practicing meditation. Sleep latency, total sleep time, total wake time, wake after sleep onset, sleep efficiency, sleep quality and depression improved in patients who used meditation.
According to principal investigator Ramadevi Gourineni, MD, director of the insomnia program at Northwestern Memorial Hospital in Evanston, Ill., insomnia is believed to be a 24-hour problem of hyperarousal, and elevated measures of arousals are seen throughout the day.
"Results of the study show that teaching deep relaxation techniques during the daytime can help improve sleep at night," said Gourineni.
The study gathered data from 11 healthy subjects between the ages of 25 and 45 years with chronic primary insomnia. Participants were divided into two intervention groups for two months: Kriya Yoga (a form of meditation that is used to focus internalized attention and has been shown to reduce measures of arousal) and health education. Subjective measures of sleep and depression were collected at baseline and after the two-month period.
Both groups received sleep hygiene education; members of the health education group also received information about health-related topics and how to improve health through exercise, nutrition, weight loss and stress management.
Abstract Title: Effects of Meditation on Sleep in Individuals with Chronic Insomnia
Results indicate that patients saw improvements in subjective sleep quality and sleep diary parameters while practicing meditation. Sleep latency, total sleep time, total wake time, wake after sleep onset, sleep efficiency, sleep quality and depression improved in patients who used meditation.
According to principal investigator Ramadevi Gourineni, MD, director of the insomnia program at Northwestern Memorial Hospital in Evanston, Ill., insomnia is believed to be a 24-hour problem of hyperarousal, and elevated measures of arousals are seen throughout the day.
"Results of the study show that teaching deep relaxation techniques during the daytime can help improve sleep at night," said Gourineni.
The study gathered data from 11 healthy subjects between the ages of 25 and 45 years with chronic primary insomnia. Participants were divided into two intervention groups for two months: Kriya Yoga (a form of meditation that is used to focus internalized attention and has been shown to reduce measures of arousal) and health education. Subjective measures of sleep and depression were collected at baseline and after the two-month period.
Both groups received sleep hygiene education; members of the health education group also received information about health-related topics and how to improve health through exercise, nutrition, weight loss and stress management.
Abstract Title: Effects of Meditation on Sleep in Individuals with Chronic Insomnia
Sleep Enforces The Temporal Sequence In Memory
We have usually quite strong memories of past events like an exciting holiday or a jolly birthday party. However it is not clear how the brain keeps track of the temporal sequence in such memories: did Paul spill a glass of wine before or after Mary left the party?
Previous findings from a research group headed by Jan Born at the University of Lübeck have confirmed the widely held view that long-term memories are formed particularly during sleep, and that this process relies on the brain replaying recently encoded experiences during the night. The same research group now provides evidence that sleep not only strengthens the content of a memory but also the particular order in which they were experienced, probably by a replay of the experiences in "forward" direction.
Students were asked to learn triplets of words presented one after the other. Afterwards they slept, whereas in a control condition no sleep was allowed. Later, recall was tested by presenting one word and asking which one came before and which one came after during learning. Sleep was found to enhance word recall, but only when the students were asked to reproduce the learned words in forward direction.
This finding shows that sleep associated consolidation of memories enforces the temporal structure of the memorized episode that otherwise might be blurred to a timeless puzzle of experiences.
Previous findings from a research group headed by Jan Born at the University of Lübeck have confirmed the widely held view that long-term memories are formed particularly during sleep, and that this process relies on the brain replaying recently encoded experiences during the night. The same research group now provides evidence that sleep not only strengthens the content of a memory but also the particular order in which they were experienced, probably by a replay of the experiences in "forward" direction.
Students were asked to learn triplets of words presented one after the other. Afterwards they slept, whereas in a control condition no sleep was allowed. Later, recall was tested by presenting one word and asking which one came before and which one came after during learning. Sleep was found to enhance word recall, but only when the students were asked to reproduce the learned words in forward direction.
This finding shows that sleep associated consolidation of memories enforces the temporal structure of the memorized episode that otherwise might be blurred to a timeless puzzle of experiences.
Internet-Based Intervention May Improve Insomnia
An online insomnia intervention based on established face-to-face cognitive behavioral therapy techniques appears to improve patients' sleep, according to a new report.
About one-third of adults report symptoms of insomnia and approximately 10 percent meet diagnostic criteria for an insomnia disorder, according to background information in the article. The condition decreases quality of life, impairs daytime functioning, has personal and public health consequences and results in an estimated $41 billion in reduced productivity every year.
Cognitive behavioral therapy—a psychological treatment focusing on the behaviors and dysfunctional thoughts that contribute to sleep problems—is one of the most effective treatments for insomnia. "Unfortunately, availability of cognitive behavioral therapy is severely limited for many reasons, including lack of trained clinicians, poor geographical distribution of knowledgeable professionals, expense and inaccessibility to treatment and clinicians," the authors write.
Lee M. Ritterband, Ph.D., of the University of Virginia Health System, Charlottesville, and colleagues evaluated the effectiveness of an Internet intervention based on cognitive behavioral therapy techniques among 44 adults (average age 44.9) who had a history of sleep difficulties lasting longer than 10 years on average. A total of 22 participants were randomly assigned to a control group and 22 received the Internet intervention, SHUTi. The highly interactive nine-week program uses text, graphics, animations, vignettes, quizzes and games to present behavioral, educational and cognitive techniques for improving sleep. For instance, patients were advised to avoid reading and watching television in the bedroom, stop daytime napping and change unhelpful beliefs and thoughts (including worries about the consequences of insomnia) that may exacerbate sleep difficulties.
Participants completed daily sleep diaries before and after the intervention and also rated their symptoms on the seven-item Insomnia Severity Index, which produces a score from zero (no symptoms) to 28 (severe insomnia). Among individuals who received the intervention, scores on the index improved from 15.73 to 6.59, whereas scores did not change for the control group. These gains were maintained at a six-month follow-up assessment.
"An Internet intervention has the potential of meeting the large unmet treatment need of the population with insomnia by providing effective treatment through the Web," they continue. "An effective and inexpensive Internet intervention would expand treatment options for large numbers of adults with insomnia, especially those whose geographical location prohibits access to relevant care, and could be a substantive first-line treatment choice."
This study was supported by a grant from the National Institute of Mental Health, National Institutes of Health.
About one-third of adults report symptoms of insomnia and approximately 10 percent meet diagnostic criteria for an insomnia disorder, according to background information in the article. The condition decreases quality of life, impairs daytime functioning, has personal and public health consequences and results in an estimated $41 billion in reduced productivity every year.
Cognitive behavioral therapy—a psychological treatment focusing on the behaviors and dysfunctional thoughts that contribute to sleep problems—is one of the most effective treatments for insomnia. "Unfortunately, availability of cognitive behavioral therapy is severely limited for many reasons, including lack of trained clinicians, poor geographical distribution of knowledgeable professionals, expense and inaccessibility to treatment and clinicians," the authors write.
Lee M. Ritterband, Ph.D., of the University of Virginia Health System, Charlottesville, and colleagues evaluated the effectiveness of an Internet intervention based on cognitive behavioral therapy techniques among 44 adults (average age 44.9) who had a history of sleep difficulties lasting longer than 10 years on average. A total of 22 participants were randomly assigned to a control group and 22 received the Internet intervention, SHUTi. The highly interactive nine-week program uses text, graphics, animations, vignettes, quizzes and games to present behavioral, educational and cognitive techniques for improving sleep. For instance, patients were advised to avoid reading and watching television in the bedroom, stop daytime napping and change unhelpful beliefs and thoughts (including worries about the consequences of insomnia) that may exacerbate sleep difficulties.
Participants completed daily sleep diaries before and after the intervention and also rated their symptoms on the seven-item Insomnia Severity Index, which produces a score from zero (no symptoms) to 28 (severe insomnia). Among individuals who received the intervention, scores on the index improved from 15.73 to 6.59, whereas scores did not change for the control group. These gains were maintained at a six-month follow-up assessment.
"An Internet intervention has the potential of meeting the large unmet treatment need of the population with insomnia by providing effective treatment through the Web," they continue. "An effective and inexpensive Internet intervention would expand treatment options for large numbers of adults with insomnia, especially those whose geographical location prohibits access to relevant care, and could be a substantive first-line treatment choice."
This study was supported by a grant from the National Institute of Mental Health, National Institutes of Health.
Sleep Strengthens Your Memory
Sleep not only protects memories from outside interferences, but also helps strengthen them, according to research presented at the American Academy of Neurology's 59th Annual Meeting in Boston.
The study looked at memory recall with and without interference (competing information). Forty-eight people between the ages of 18 and 30 took part in the study. All had normal, healthy sleep routines and were not taking any medications. Participants were divided evenly into four groups--a wake group without interference, a wake group with interference, a sleep group without interference and a sleep group with interference. All groups were taught the same 20 pairs of words in the initial training session.
The wake groups were taught the word pairings at 9 a.m. and then tested on them at 9 p.m. after 12 hours awake. The sleep groups were taught the word pairs at 9 p.m. and tested on them at 9 a.m. after a night of sleep. Just prior to testing, the interference groups were given a second list of word pairs to remember. The first word in each pair was the same on both lists, but the second word was different, testing the brain's ability to handle competing information, known as interference. The interference groups were then tested on both lists.
The study found that people who slept after learning the information performed best, successfully recalling more words. Those in the sleep group without interference were able to recall 12 percent more word pairings from the first list than the wake group without interference. With interference, the recall rate was 44 percent higher for the sleep group.
"This is the first study to show that sleep protects memories from interference," said study author Jeffrey Ellenbogen, MD, with Harvard Medical School in Boston, MA, and Fellow of the American Academy of Neurology. "These results provide important insights into how the sleeping brain interacts with memories: it appears to strengthen them. Perhaps, then, sleep disorders might worsen memory problems seen in dementia."
The study looked at memory recall with and without interference (competing information). Forty-eight people between the ages of 18 and 30 took part in the study. All had normal, healthy sleep routines and were not taking any medications. Participants were divided evenly into four groups--a wake group without interference, a wake group with interference, a sleep group without interference and a sleep group with interference. All groups were taught the same 20 pairs of words in the initial training session.
The wake groups were taught the word pairings at 9 a.m. and then tested on them at 9 p.m. after 12 hours awake. The sleep groups were taught the word pairs at 9 p.m. and tested on them at 9 a.m. after a night of sleep. Just prior to testing, the interference groups were given a second list of word pairs to remember. The first word in each pair was the same on both lists, but the second word was different, testing the brain's ability to handle competing information, known as interference. The interference groups were then tested on both lists.
The study found that people who slept after learning the information performed best, successfully recalling more words. Those in the sleep group without interference were able to recall 12 percent more word pairings from the first list than the wake group without interference. With interference, the recall rate was 44 percent higher for the sleep group.
"This is the first study to show that sleep protects memories from interference," said study author Jeffrey Ellenbogen, MD, with Harvard Medical School in Boston, MA, and Fellow of the American Academy of Neurology. "These results provide important insights into how the sleeping brain interacts with memories: it appears to strengthen them. Perhaps, then, sleep disorders might worsen memory problems seen in dementia."
Mild Head Injuries Increase Risk Of Sleep Disorders
A mild head injury can increase your chance of developing a sleep disorder, according to a study published in the April 3, 2007, issue of Neurology®, the scientific journal of the American Academy of Neurology. Researchers say these findings highlight the need for improved diagnosis and treatment of sleep disorders in mild traumatic brain injury patients who complain of insomnia.
"As many as 40 to 65 percent of people with mild traumatic brain injury complain of insomnia," said study author Liat Ayalon, PhD, with the University of California, San Diego. "This is concerning since sleeping problems may exacerbate other brain injury symptoms such as headache, emotional distress, and cognitive impairment, making the rehabilitation process much harder."
For the study, researchers assessed 42 people who reported to the Sheba Medical Center in Israel with complaints of insomnia after mild traumatic brain injury. Those suspected of having a circadian rhythm sleep disorder (CRSD) (i.e. problems with the timing of sleep) underwent scans, sleep studies, and had their oral temperature and saliva melatonin measured.
The study found 15 of the 42 patients, or 36 percent, had a CRSD. Of those, eight people had a delayed sleep phase syndrome with problems falling asleep and waking up, and seven people had irregular sleep-wake patterns.
"The frequency of sleep disorders in this study is considerably higher than the rate of these disorders among people attending sleep clinics for insomnia, which is seven to 10 percent," said Ayalon.
Ayalon said these findings suggest that sleep disorders that involve changes in the timing of sleep may be relatively frequent among brain injury patients and should be considered when these patients report sleeping problems to avoid misdiagnosis. "Misdiagnosis of these patients as insomniac may lead to prescription of medications, which help people fall asleep but don't help normalize the sleep-wake cycle," said Ayalon.
In addition, Ayalon said since circadian rhythm sleep disorders are often associated with cognitive and psychological problems, treatment might ultimately lead to improvement in other brain injury related symptoms. Ayalon said further studies are needed to explain the mechanism behind CRSDs in people with brain injury.
"As many as 40 to 65 percent of people with mild traumatic brain injury complain of insomnia," said study author Liat Ayalon, PhD, with the University of California, San Diego. "This is concerning since sleeping problems may exacerbate other brain injury symptoms such as headache, emotional distress, and cognitive impairment, making the rehabilitation process much harder."
For the study, researchers assessed 42 people who reported to the Sheba Medical Center in Israel with complaints of insomnia after mild traumatic brain injury. Those suspected of having a circadian rhythm sleep disorder (CRSD) (i.e. problems with the timing of sleep) underwent scans, sleep studies, and had their oral temperature and saliva melatonin measured.
The study found 15 of the 42 patients, or 36 percent, had a CRSD. Of those, eight people had a delayed sleep phase syndrome with problems falling asleep and waking up, and seven people had irregular sleep-wake patterns.
"The frequency of sleep disorders in this study is considerably higher than the rate of these disorders among people attending sleep clinics for insomnia, which is seven to 10 percent," said Ayalon.
Ayalon said these findings suggest that sleep disorders that involve changes in the timing of sleep may be relatively frequent among brain injury patients and should be considered when these patients report sleeping problems to avoid misdiagnosis. "Misdiagnosis of these patients as insomniac may lead to prescription of medications, which help people fall asleep but don't help normalize the sleep-wake cycle," said Ayalon.
In addition, Ayalon said since circadian rhythm sleep disorders are often associated with cognitive and psychological problems, treatment might ultimately lead to improvement in other brain injury related symptoms. Ayalon said further studies are needed to explain the mechanism behind CRSDs in people with brain injury.
People Learn While They Sleep, Study Suggests
People may be learning while they're sleeping -- an unconscious form of memory that is still not well understood, according to a study by Michigan State University researchers.
The findings are highlighted in the Journal of Experimental Psychology: General.
"We speculate that we may be investigating a separate form of memory, distinct from traditional memory systems," said Kimberly Fenn, assistant professor of psychology and lead researcher on the project. "There is substantial evidence that during sleep, your brain is processing information without your awareness and this ability may contribute to memory in a waking state."
In the study of more than 250 people, Fenn and Zach Hambrick, associate professor of psychology, suggest people derive vastly different effects from this "sleep memory" ability, with some memories improving dramatically and others not at all. This ability is a new, previously undefined form of memory.
"You and I could go to bed at the same time and get the same amount of sleep," Fenn said, "but while your memory may increase substantially, there may be no change in mine." She added that most people showed improvement.
Fenn said she believes this potential separate memory ability is not being captured by traditional intelligence tests and aptitude tests such as the SAT and ACT.
"This is the first step to investigate whether or not this potential new memory construct is related to outcomes such as classroom learning," she said.
It also reinforces the need for a good night's sleep. According to the National Sleep Foundation, people are sleeping less every year, with 63 percent of Americans saying their sleep needs are not being met during the week.
"Simply improving your sleep could potentially improve your performance in the classroom," Fenn said.
The findings are highlighted in the Journal of Experimental Psychology: General.
"We speculate that we may be investigating a separate form of memory, distinct from traditional memory systems," said Kimberly Fenn, assistant professor of psychology and lead researcher on the project. "There is substantial evidence that during sleep, your brain is processing information without your awareness and this ability may contribute to memory in a waking state."
In the study of more than 250 people, Fenn and Zach Hambrick, associate professor of psychology, suggest people derive vastly different effects from this "sleep memory" ability, with some memories improving dramatically and others not at all. This ability is a new, previously undefined form of memory.
"You and I could go to bed at the same time and get the same amount of sleep," Fenn said, "but while your memory may increase substantially, there may be no change in mine." She added that most people showed improvement.
Fenn said she believes this potential separate memory ability is not being captured by traditional intelligence tests and aptitude tests such as the SAT and ACT.
"This is the first step to investigate whether or not this potential new memory construct is related to outcomes such as classroom learning," she said.
It also reinforces the need for a good night's sleep. According to the National Sleep Foundation, people are sleeping less every year, with 63 percent of Americans saying their sleep needs are not being met during the week.
"Simply improving your sleep could potentially improve your performance in the classroom," Fenn said.
Naps Help Your Memory, New Study Suggests
A ninety minute daytime nap helps speed up the process of long term memory consolidation, a recent study conducted by Prof. Avi Karni and Dr. Maria Korman of the Center for Brain and Behavior Research at the University of Haifa found. "We still don't know the exact mechanism of the memory process that occurs during sleep, but the results of this research suggest the possibility that it is possible to speed up memory consolidation, and in the future, we may be able to do it artificially," said Prof. Karni.
Long term memory is defined as a permanent memory that doesn't disappear or that disappears after many years. This part of our memory is divided into two types -- memories of "what" (for example: what happened yesterday or what one remembers from an article one read yesterday) and memories of "how to" (for example: how to read Hebrew, how to drive, play basketball or play the piano).
In this new research, which was conducted by researchers at the University of Haifa in cooperation with the Sleep Laboratory at the Sheba Medical Center and researchers from the Department of Psychology at the University of Montreal, it was revealed that a daytime nap changes the course of consolidation in the brain. Two groups of participants in the study practiced a repeated motor activity which consisted of bringing the thumb and a finger together at a specific sequence. The research examined the "how" aspect of memory in the participants' ability to perform the task quickly and in the correct sequence. One of the groups was allowed to nap for an hour and a half after learning the task while the other group stayed awake.
The group that slept in the afternoon showed a distinct improvement in their task performance by that evening, as opposed to the group that stayed awake, which did not exhibit any improvement. Following an entire night's sleep, both groups exhibited the same skill level. "This part of the research showed that a daytime nap speeds up performance improvement in the brain. After a night's sleep the two groups were at the same level, but the group that slept in the afternoon improved much faster than the group that stayed awake," stressed Prof. Karni.
A second experiment showed that another aspect of memory consolidation is accelerated by sleep. It was previously shown that during the 6-8 hours after completing an effective practice session, the neural process of "how" memory consolidation is susceptible to interference, such that if, for example, one learns or performs a second, different task, one's brain will not be able to successfully remember the first trained task.
A third group of participants in the University of Haifa study learned a different thumb-to-finger movement sequence two hours after practicing the first task. As the second task was introduced at the beginning of the 6-8 hour period during which the brain consolidates memories, the second task disturbed the memory consolidation process and this group did not show any improvement in their ability to perform the task, neither in the evening of that day nor on the following morning. However, when a fourth group of participants was allowed a 90 minute nap between learning the first set of movements and the second, they did not show much improvement in the evening, but on the following morning these participants showed a marked improvement of their performance, as if there had been no interference at all.
"This part of the study demonstrated, for the first time, that daytime sleep can shorten the time "how to" memory becomes immune to interference and forgetting. Instead of 6-8 hours, the brain consolidated the memory during the 90 minute nap," explains Prof. Karni who added that while this study demonstrates that the process of memory consolidation is accelerated during daytime sleep, it is still not clear which mechanisms sleep accelerates in the process.
The elucidation of these mechanisms, say the researchers, could enable the development of methods to accelerate memory consolidation in adults and to create stable memories in a short time. Until then, if you need to memorize something quickly or if your schedule is filled with different activities which require learning "how" to do things, it is worth finding the time for an afternoon nap.
The research was published in the scientific journal Nature Neuroscience.
Long term memory is defined as a permanent memory that doesn't disappear or that disappears after many years. This part of our memory is divided into two types -- memories of "what" (for example: what happened yesterday or what one remembers from an article one read yesterday) and memories of "how to" (for example: how to read Hebrew, how to drive, play basketball or play the piano).
In this new research, which was conducted by researchers at the University of Haifa in cooperation with the Sleep Laboratory at the Sheba Medical Center and researchers from the Department of Psychology at the University of Montreal, it was revealed that a daytime nap changes the course of consolidation in the brain. Two groups of participants in the study practiced a repeated motor activity which consisted of bringing the thumb and a finger together at a specific sequence. The research examined the "how" aspect of memory in the participants' ability to perform the task quickly and in the correct sequence. One of the groups was allowed to nap for an hour and a half after learning the task while the other group stayed awake.
The group that slept in the afternoon showed a distinct improvement in their task performance by that evening, as opposed to the group that stayed awake, which did not exhibit any improvement. Following an entire night's sleep, both groups exhibited the same skill level. "This part of the research showed that a daytime nap speeds up performance improvement in the brain. After a night's sleep the two groups were at the same level, but the group that slept in the afternoon improved much faster than the group that stayed awake," stressed Prof. Karni.
A second experiment showed that another aspect of memory consolidation is accelerated by sleep. It was previously shown that during the 6-8 hours after completing an effective practice session, the neural process of "how" memory consolidation is susceptible to interference, such that if, for example, one learns or performs a second, different task, one's brain will not be able to successfully remember the first trained task.
A third group of participants in the University of Haifa study learned a different thumb-to-finger movement sequence two hours after practicing the first task. As the second task was introduced at the beginning of the 6-8 hour period during which the brain consolidates memories, the second task disturbed the memory consolidation process and this group did not show any improvement in their ability to perform the task, neither in the evening of that day nor on the following morning. However, when a fourth group of participants was allowed a 90 minute nap between learning the first set of movements and the second, they did not show much improvement in the evening, but on the following morning these participants showed a marked improvement of their performance, as if there had been no interference at all.
"This part of the study demonstrated, for the first time, that daytime sleep can shorten the time "how to" memory becomes immune to interference and forgetting. Instead of 6-8 hours, the brain consolidated the memory during the 90 minute nap," explains Prof. Karni who added that while this study demonstrates that the process of memory consolidation is accelerated during daytime sleep, it is still not clear which mechanisms sleep accelerates in the process.
The elucidation of these mechanisms, say the researchers, could enable the development of methods to accelerate memory consolidation in adults and to create stable memories in a short time. Until then, if you need to memorize something quickly or if your schedule is filled with different activities which require learning "how" to do things, it is worth finding the time for an afternoon nap.
The research was published in the scientific journal Nature Neuroscience.
Sleep May Be Important In Regulating Emotional Responses
According to a research abstract that will be presented on June11, at Sleep 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies, sleep selectively preservers memories that are emotionally salient and relevant to future goals when sleep follows soon after learning. Effects persist for as long as four months after the memory is created.
Results indicate that the sleeping brain seems to calculate what is most important about an experience and selects only what is adaptive for consolidation and long term storage. Across long delays of 24 hours, or even three–to-four months, sleeping soon after learning preserved the trade-off (compared to waiting an entire day before going to sleep).
According to lead author, Jessica Payne, PhD, of Harvard Medical School in Boston MA, It was surprising that in addition to seeing the enhancement of negative memories over neutral scenes, there was also selectivity within the emotional scenes themselves, with sleep only consolidating what is most relevant, adaptive and useful about the scenes. It was even more surprising that this selectivity lasted for a full day and even months later if sleep came soon after learning.
"It may be that the chemical and physiological aspects of sleep underlying memory consolidation are more effective if a particular memory is 'tagged' shortly prior to sleeping," said Payne.
The study included data from 44 college students between the ages of 18 and 22 who encoded scenes with neutral or negative objects on a neutral background and were tested on memory for objects and backgrounds 24 hours later. Half of the participants were randomly assigned to the 'sleep first' group, which trained and tested on the scenes between the hours of 7 and 9 p.m. while the other half was assigned to the 'wake-first' group which trained and tested on the scenes between the hours of 9 and 11 a.m. Four months later, participants were once again tested on their memory of the scenes.
Negative, but not neutral objects were better remembered in the sleep-first than wake-first group. Backgrounds associated with negative, but not neutral objects were more poorly remembered in the sleep-first compared to the wake-first group. Thus, while negative object memory was enhanced in the sleep-first group compared to the wake-first group, memory for the backgrounds on which they were presented was impaired in the sleep-first group compared to the wake-first group. This pattern persisted four months later, with emotional objects being preferentially retained in the sleep-first group only.
Payne said that sleep is beneficial for memory and that we remember things best when we 'stagger' our learning episodes across time.
Abstract Title: Sleep Promotes Lasting Changes in Memory for Emotional Scenes
Results indicate that the sleeping brain seems to calculate what is most important about an experience and selects only what is adaptive for consolidation and long term storage. Across long delays of 24 hours, or even three–to-four months, sleeping soon after learning preserved the trade-off (compared to waiting an entire day before going to sleep).
According to lead author, Jessica Payne, PhD, of Harvard Medical School in Boston MA, It was surprising that in addition to seeing the enhancement of negative memories over neutral scenes, there was also selectivity within the emotional scenes themselves, with sleep only consolidating what is most relevant, adaptive and useful about the scenes. It was even more surprising that this selectivity lasted for a full day and even months later if sleep came soon after learning.
"It may be that the chemical and physiological aspects of sleep underlying memory consolidation are more effective if a particular memory is 'tagged' shortly prior to sleeping," said Payne.
The study included data from 44 college students between the ages of 18 and 22 who encoded scenes with neutral or negative objects on a neutral background and were tested on memory for objects and backgrounds 24 hours later. Half of the participants were randomly assigned to the 'sleep first' group, which trained and tested on the scenes between the hours of 7 and 9 p.m. while the other half was assigned to the 'wake-first' group which trained and tested on the scenes between the hours of 9 and 11 a.m. Four months later, participants were once again tested on their memory of the scenes.
Negative, but not neutral objects were better remembered in the sleep-first than wake-first group. Backgrounds associated with negative, but not neutral objects were more poorly remembered in the sleep-first compared to the wake-first group. Thus, while negative object memory was enhanced in the sleep-first group compared to the wake-first group, memory for the backgrounds on which they were presented was impaired in the sleep-first group compared to the wake-first group. This pattern persisted four months later, with emotional objects being preferentially retained in the sleep-first group only.
Payne said that sleep is beneficial for memory and that we remember things best when we 'stagger' our learning episodes across time.
Abstract Title: Sleep Promotes Lasting Changes in Memory for Emotional Scenes
New Protein Implicated In Autism
Autism is a common neurodevelopmental disorder characterized by severely impaired social, communicative, and behavioral functions. It is thought that genetic make-up predisposes an individual to autism, and several genes have been associated with the development of autism.
Although a region of human chromosome 7 has been identified to be associated with susceptibility to autism, none of the genes in this region had been directly implicated in the disorder until researchers from the RIKEN Brain Science Institute in Japan demonstrated that mice lacking the protein CADPS2 exhibited autistic-like characteristics.
In the study, which appears online on March 22 in advance of publication in the April print issue of the Journal of Clinical Investigation, Teiichi Furuichi and colleagues show that mice lacking CADPS2, which is encoded by a gene in the autism susceptibility region of human chromosome 7, had impaired social interactions (when pairs of CADPS2-deficient mice that had never met were placed together they interacted substantially less frequently than pairs of wild-type mice that had never met), hyperactivity, and decreased exploration of a new environment; all of which are characteristics of individuals with autism.
Importantly, an abnormal form of CADPS2 mRNA (which is an intermediate in the conversion of the CADPS2 gene to CADPS2 protein) was detected in some individuals with autism and was never detected in their healthy immediate relatives, leading to the suggestion that defects in CADPS2 function might predispose individuals to develop autism.
Although a region of human chromosome 7 has been identified to be associated with susceptibility to autism, none of the genes in this region had been directly implicated in the disorder until researchers from the RIKEN Brain Science Institute in Japan demonstrated that mice lacking the protein CADPS2 exhibited autistic-like characteristics.
In the study, which appears online on March 22 in advance of publication in the April print issue of the Journal of Clinical Investigation, Teiichi Furuichi and colleagues show that mice lacking CADPS2, which is encoded by a gene in the autism susceptibility region of human chromosome 7, had impaired social interactions (when pairs of CADPS2-deficient mice that had never met were placed together they interacted substantially less frequently than pairs of wild-type mice that had never met), hyperactivity, and decreased exploration of a new environment; all of which are characteristics of individuals with autism.
Importantly, an abnormal form of CADPS2 mRNA (which is an intermediate in the conversion of the CADPS2 gene to CADPS2 protein) was detected in some individuals with autism and was never detected in their healthy immediate relatives, leading to the suggestion that defects in CADPS2 function might predispose individuals to develop autism.
Gene Expression Abnormalities in Autism Identified
Genetic studies find dysregulation in pathways that govern development of the prefrontal cortex in young patients with autism
A study led by Eric Courchesne, PhD, director of the Autism Center of Excellence at the University of California, San Diego School of Medicine has, for the first time, identified in young autism patients genetic mechanisms involved in abnormal early brain development and overgrowth that occurs in the disorder. The findings suggest novel genetic and molecular targets that could lead to discoveries of new prevention strategies and treatment for the disorder.
The study to be published on March 22 in PLoS Genetics uncovered differences in gene expression between brain tissue from young (2 to14 years old) and adult individuals with autism syndrome disorder, providing important clues why brain growth and development is abnormal in this disorder.
Courchesne first identified the link between early brain overgrowth and autism in a landmark study published by the Journal of the American Medical Association (JAMA) in 2003. Next, he tested the possibility that brain overgrowth might result from an abnormal excess of brain cells. In November 2011, his study, also published in JAMA, discovered a 67 percent excess of brain cells in a major region of the brain, the prefrontal cortex -- a part of the brain associated with social, communication and cognitive development.
"Our next step was to see whether there might be abnormalities of genetic functioning in that same region that might give us insight into why there are too many cells and why that specific region does not develop normally in autism," said Courchesne.
In the new study, the researchers looked towards genes for answers, and showed that genetic mechanisms that normally regulate the number of cortical neurons are abnormal. "The genes that control the number of brain cells did not have the normal functional expression, and the level of gene expression that governs the pattern of neural organization across the prefrontal cortex is turned down. There are abnormal numbers and patterns of brain cells, and subsequently the pattern is disturbed," Courchesne said. "This probably leads to too many brain cells in some locations, such as prefrontal cortex, but perhaps too few in other regions of cortex as well."
In addition, the scientists discovered a turning down of the genetic mechanisms responsible for detecting DNA defects and correcting or removing affected cells during periods of rapid prenatal development.
Autism is a highly heritable neurodevelopmental disorder, yet the genetic underpinnings in the brain at young ages have remained largely unknown. Until now, few studies have been able to investigate whole-genome gene expression and genotype variation in the brains of young patients with autism, especially in regions such as the prefrontal cortex that display the greatest growth abnormality.
Scientists -- including co-first authors Maggie Chow, PhD, and Tiziano Pramparo, PhD, at UC San Diego -- identified abnormal brain gene expression patterns using whole-genome analysis of mRNA levels and copy number variations from 33 autistic and control postmortem brain samples. They found evidence of dysregulation in the pathways that govern cell number, cortical patterning and cell differentiation in the young autistic prefrontal cortex. In contrast, in adult patients with autism, the study found that this area of the brain shows dysregulation of signaling and repair pathways.
"Our results indicate that gene expression abnormalities change across the lifespan in autism, and that dysregulated processes in the developing brain of autistic patients differ from those detected at adult ages," said Courchesne. "The dysregulated genetic pathways we found at young ages in autism may underlie the excess of neurons -- and early brain overgrowth -- associated with this disorder."
Additional contributors include co-senior authors Nicholas J. Schork, PhD, biostatistician at The Scripps Research Institute in La Jolla, CA, and Anthony Wynshaw-Boris, professor of pediatrics at UC San Francisco; Mary E. Winn and Sarah Murray, The Scripps Research Institute; Lauren Weiss and Haim Belinson, UC San Francisco; Jian-Bing Fan and Craig April, Illumina, Inc.; Cynthia Carter Barnes, Hai-Ri Li and Xiang-Dong Fu, UC San Diego.
The research was supported by funds from the Simons Foundation, The Peter Emch Family Foundation, Autism Speaks, the Thursday Club Juniors and the UCSD-NIH Autism Center of Excellence.
A study led by Eric Courchesne, PhD, director of the Autism Center of Excellence at the University of California, San Diego School of Medicine has, for the first time, identified in young autism patients genetic mechanisms involved in abnormal early brain development and overgrowth that occurs in the disorder. The findings suggest novel genetic and molecular targets that could lead to discoveries of new prevention strategies and treatment for the disorder.
The study to be published on March 22 in PLoS Genetics uncovered differences in gene expression between brain tissue from young (2 to14 years old) and adult individuals with autism syndrome disorder, providing important clues why brain growth and development is abnormal in this disorder.
Courchesne first identified the link between early brain overgrowth and autism in a landmark study published by the Journal of the American Medical Association (JAMA) in 2003. Next, he tested the possibility that brain overgrowth might result from an abnormal excess of brain cells. In November 2011, his study, also published in JAMA, discovered a 67 percent excess of brain cells in a major region of the brain, the prefrontal cortex -- a part of the brain associated with social, communication and cognitive development.
"Our next step was to see whether there might be abnormalities of genetic functioning in that same region that might give us insight into why there are too many cells and why that specific region does not develop normally in autism," said Courchesne.
In the new study, the researchers looked towards genes for answers, and showed that genetic mechanisms that normally regulate the number of cortical neurons are abnormal. "The genes that control the number of brain cells did not have the normal functional expression, and the level of gene expression that governs the pattern of neural organization across the prefrontal cortex is turned down. There are abnormal numbers and patterns of brain cells, and subsequently the pattern is disturbed," Courchesne said. "This probably leads to too many brain cells in some locations, such as prefrontal cortex, but perhaps too few in other regions of cortex as well."
In addition, the scientists discovered a turning down of the genetic mechanisms responsible for detecting DNA defects and correcting or removing affected cells during periods of rapid prenatal development.
Autism is a highly heritable neurodevelopmental disorder, yet the genetic underpinnings in the brain at young ages have remained largely unknown. Until now, few studies have been able to investigate whole-genome gene expression and genotype variation in the brains of young patients with autism, especially in regions such as the prefrontal cortex that display the greatest growth abnormality.
Scientists -- including co-first authors Maggie Chow, PhD, and Tiziano Pramparo, PhD, at UC San Diego -- identified abnormal brain gene expression patterns using whole-genome analysis of mRNA levels and copy number variations from 33 autistic and control postmortem brain samples. They found evidence of dysregulation in the pathways that govern cell number, cortical patterning and cell differentiation in the young autistic prefrontal cortex. In contrast, in adult patients with autism, the study found that this area of the brain shows dysregulation of signaling and repair pathways.
"Our results indicate that gene expression abnormalities change across the lifespan in autism, and that dysregulated processes in the developing brain of autistic patients differ from those detected at adult ages," said Courchesne. "The dysregulated genetic pathways we found at young ages in autism may underlie the excess of neurons -- and early brain overgrowth -- associated with this disorder."
Additional contributors include co-senior authors Nicholas J. Schork, PhD, biostatistician at The Scripps Research Institute in La Jolla, CA, and Anthony Wynshaw-Boris, professor of pediatrics at UC San Francisco; Mary E. Winn and Sarah Murray, The Scripps Research Institute; Lauren Weiss and Haim Belinson, UC San Francisco; Jian-Bing Fan and Craig April, Illumina, Inc.; Cynthia Carter Barnes, Hai-Ri Li and Xiang-Dong Fu, UC San Diego.
The research was supported by funds from the Simons Foundation, The Peter Emch Family Foundation, Autism Speaks, the Thursday Club Juniors and the UCSD-NIH Autism Center of Excellence.
Learning To Shape Your Brain Activity
A study in the Oct. 1 issue of the journal Sleep shows that the successful manipulation of sensorimotor rhythm (SMR) amplitude by instrumental SMR conditioning (ISC) improved sleep quality as well as declarative learning. ISC might thus be considered a promising non-pharmacological treatment for primary insomnia.
This study allowed participants to "shape their own brain activity" by directly modifying certain electroencephalographic (EEG) activities. Findings support the theory that an increase in relaxation and a decrease in muscle tension might lead to less movement during sleep and thereby augment the restorative and learning enhancement benefits of sleep. Significant changes in SMR amplitude from early to late conditioning sessions confirmed the success of ISC. EEG changes transferred into sleep and improved immediate memory retrieval after learning. The study's 27 participants were able to fall asleep faster (decrease in "sleep onset latency") and increase memory performance after two weeks of ISC.
"The aim of the study was to improve sleep quality and memory performance by 'rewarding' the existence of certain activities of the brain," said the study's workgroup leader, Dr. Manuel Schabus, researcher for the division of physiological psychology at the University of Salzburg in Austria.
Instrumental conditioning of different EEG parameters has long been used as a therapeutic tool to treat different kinds of disorders, including epilepsy and attention–deficit/hyperactivity disorder (ADHD). Prior research has found that ISC can be effective in treating psychophysiological insomnia, a form of insomnia associated with worrying.
Twenty-seven healthy subjects were randomly assigned to either an ISC group or a randomized frequency group in order to examine the effects of ISC on sleep as well as declarative memory performance. Participants attended the laboratory on 13 occasions, during 10 of which they were connected to a feedback system that allowed them to keep track of their current brain activity by looking at a computer screen. Participants were encouraged to use physiological relaxation combined with positive mental activity in order to "shape their brainwaves"; all participants remained blind to their group assignment and were not debriefed until after the investigation had ended.
Participants trained the enhancement of the SMR over the course of two weeks and were rewarded with a pleasant image whenever they succeeded to enhance this specific type of brain activity. Subjective data about sleep quality and depression and objective data about memory and intelligence were also collected. Participants were asked to perform a declarative word-pair association task before and after a 90-minute nap periods in the laboratory; naps were taken before and after treatment sessions.
The researchers suggest that future studies focus on the effects of ISC on various cognitive tasks and address the potential clinical significance of this kind of training for the long-term treatment of insomnia.
This study allowed participants to "shape their own brain activity" by directly modifying certain electroencephalographic (EEG) activities. Findings support the theory that an increase in relaxation and a decrease in muscle tension might lead to less movement during sleep and thereby augment the restorative and learning enhancement benefits of sleep. Significant changes in SMR amplitude from early to late conditioning sessions confirmed the success of ISC. EEG changes transferred into sleep and improved immediate memory retrieval after learning. The study's 27 participants were able to fall asleep faster (decrease in "sleep onset latency") and increase memory performance after two weeks of ISC.
"The aim of the study was to improve sleep quality and memory performance by 'rewarding' the existence of certain activities of the brain," said the study's workgroup leader, Dr. Manuel Schabus, researcher for the division of physiological psychology at the University of Salzburg in Austria.
Instrumental conditioning of different EEG parameters has long been used as a therapeutic tool to treat different kinds of disorders, including epilepsy and attention–deficit/hyperactivity disorder (ADHD). Prior research has found that ISC can be effective in treating psychophysiological insomnia, a form of insomnia associated with worrying.
Twenty-seven healthy subjects were randomly assigned to either an ISC group or a randomized frequency group in order to examine the effects of ISC on sleep as well as declarative memory performance. Participants attended the laboratory on 13 occasions, during 10 of which they were connected to a feedback system that allowed them to keep track of their current brain activity by looking at a computer screen. Participants were encouraged to use physiological relaxation combined with positive mental activity in order to "shape their brainwaves"; all participants remained blind to their group assignment and were not debriefed until after the investigation had ended.
Participants trained the enhancement of the SMR over the course of two weeks and were rewarded with a pleasant image whenever they succeeded to enhance this specific type of brain activity. Subjective data about sleep quality and depression and objective data about memory and intelligence were also collected. Participants were asked to perform a declarative word-pair association task before and after a 90-minute nap periods in the laboratory; naps were taken before and after treatment sessions.
The researchers suggest that future studies focus on the effects of ISC on various cognitive tasks and address the potential clinical significance of this kind of training for the long-term treatment of insomnia.
Sleeping After Processing New Info Most Effective
Nodding off in class may not be such a bad idea after all. New research from the University of Notre Dame shows that going to sleep shortly after learning new material is most beneficial for recall.
Notre Dame psychologist Jessica Payne and colleagues studied 207 students who habitually slept for at least six hours per night. Participants were randomly assigned to study declarative, semantically related or unrelated word pairs at 9 a.m. or 9 p.m., and returned for testing 30 minutes, 12 hours or 24 hours later. Declarative memory refers to the ability to consciously remember facts and events, and can be broken down into episodic memory (memory for events) and semantic memory (memory for facts about the world). People routinely use both types of memory every day -- recalling where we parked today or learning how a colleague prefers to be addressed.
At the 12-hour retest, memory overall was superior following a night of sleep compared to a day of wakefulness. However, this performance difference was a result of a pronounced deterioration in memory for unrelated word pairs; there was no sleep-wake difference for related word pairs. At the 24-hour retest, with all subjects having received both a full night of sleep and a full day of wakefulness, subjects' memories were superior when sleep occurred shortly after learning, rather than following a full day of wakefulness.
"Our study confirms that sleeping directly after learning something new is beneficial for memory. What's novel about this study is that we tried to shine light on sleep's influence on both types of declarative memory by studying semantically unrelated and related word pairs," Payne says.
"Since we found that sleeping soon after learning benefited both types of memory, this means that it would be a good thing to rehearse any information you need to remember just prior to going to bed. In some sense, you may be 'telling' the sleeping brain what to consolidate."
Notre Dame psychologist Jessica Payne and colleagues studied 207 students who habitually slept for at least six hours per night. Participants were randomly assigned to study declarative, semantically related or unrelated word pairs at 9 a.m. or 9 p.m., and returned for testing 30 minutes, 12 hours or 24 hours later. Declarative memory refers to the ability to consciously remember facts and events, and can be broken down into episodic memory (memory for events) and semantic memory (memory for facts about the world). People routinely use both types of memory every day -- recalling where we parked today or learning how a colleague prefers to be addressed.
At the 12-hour retest, memory overall was superior following a night of sleep compared to a day of wakefulness. However, this performance difference was a result of a pronounced deterioration in memory for unrelated word pairs; there was no sleep-wake difference for related word pairs. At the 24-hour retest, with all subjects having received both a full night of sleep and a full day of wakefulness, subjects' memories were superior when sleep occurred shortly after learning, rather than following a full day of wakefulness.
"Our study confirms that sleeping directly after learning something new is beneficial for memory. What's novel about this study is that we tried to shine light on sleep's influence on both types of declarative memory by studying semantically unrelated and related word pairs," Payne says.
"Since we found that sleeping soon after learning benefited both types of memory, this means that it would be a good thing to rehearse any information you need to remember just prior to going to bed. In some sense, you may be 'telling' the sleeping brain what to consolidate."
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