Neuroscience

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Posts tagged neuroscience

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Why Some Remember Dreams, Others Don’t People who tend to remember their dreams also respond more strongly than others to hearing their name when they’re awake, new research suggests. Everyone dreams during sleep, but not everyone recalls the mental escapade the next day, and scientists aren’t sure why some people remember more than others. To find out, researchers used electroencephalography to record the electrical activity in the brains of 36 people while the participants listened to background tunes, and occasionally heard their own first name. The brain measurements were taken during wakefulness and sleep. Half of the participants were called high recallers, because they reported remembering their dreams almost every day, whereas the other half, low recallers, said they only remembered their dreams once or twice a month. When asleep, both groups showed similar changes in brain activity in response to hearing their names, which were played quietly enough not to wake them. However, when awake, high recallers showed a more sustained decrease in a brain wave called the alpha wave when they heard their names, compared with the low recallers. "It was quite surprising to see a difference between the groups during wakefulness," said study researcher Perrine Ruby, neuroscientist at Lyon Neuroscience Research Center in France. The difference could reflect variations in the brains of high and low recallers that could have a role in how they dream, too, Ruby said. Who remembers their dreams A well-established theory suggests that a decrease in the alpha wave is a sign that brain regions are being inhibited from responding to outside stimuli. Studies show that when people hear a sudden sound or open their eyes, and more brain regions become active, the alpha wave is reduced. In the study, as predicted, both groups showed a decrease in the alpha wave when they heard their names while awake. But high recallers showed a more prolonged decrease, which may be a sign their brains became more widely activated when they heard their names. In other words, high recallers may engage more brain regions when processing sounds while awake, compared with low recallers, the researchers said. While people are asleep, the alpha wave behaves in the opposite way —it increases when a sudden sound is heard. Scientists aren’t certain why this happens, but one idea is that it protects the brain from being interrupted by sounds during sleep, Ruby said. Indeed, the study participants showed an increase in the alpha wave in response to sounds during sleep, and there was no difference between the groups. One possibility to explain the lack of difference, the researchers said, could be that perhaps high recallers had a larger increase in alpha waves, but it was so high that they woke up. Time spent awake, during the night The researchers saw that high recallers awoke more frequently during the night. They were awake, on average, for 30 minutes during the night, whereas low recallers were awake for 14 minutes. However, Ruby said “both figures are in the normal range, it’s not that there’s something wrong with either group.” Altogether, the results suggest the brain of high recallers may be more reactive to stimuli such as sounds, which could make them wake up more easily. It is more likely a person would remember their dreams if they are awakened immediately after one, Ruby said. However, waking up at night can account for only a part of the differences people show in remembering dreams. “There’s still much more to understand,” she said. The study is published online (Aug. 13) in the journal Frontiers in Psychology.

Why Some Remember Dreams, Others Don’t

People who tend to remember their dreams also respond more strongly than others to hearing their name when they’re awake, new research suggests.

Everyone dreams during sleep, but not everyone recalls the mental escapade the next day, and scientists aren’t sure why some people remember more than others.

To find out, researchers used electroencephalography to record the electrical activity in the brains of 36 people while the participants listened to background tunes, and occasionally heard their own first name. The brain measurements were taken during wakefulness and sleep. Half of the participants were called high recallers, because they reported remembering their dreams almost every day, whereas the other half, low recallers, said they only remembered their dreams once or twice a month.

When asleep, both groups showed similar changes in brain activity in response to hearing their names, which were played quietly enough not to wake them.

However, when awake, high recallers showed a more sustained decrease in a brain wave called the alpha wave when they heard their names, compared with the low recallers.

"It was quite surprising to see a difference between the groups during wakefulness," said study researcher Perrine Ruby, neuroscientist at Lyon Neuroscience Research Center in France.

The difference could reflect variations in the brains of high and low recallers that could have a role in how they dream, too, Ruby said.

Who remembers their dreams

A well-established theory suggests that a decrease in the alpha wave is a sign that brain regions are being inhibited from responding to outside stimuli. Studies show that when people hear a sudden sound or open their eyes, and more brain regions become active, the alpha wave is reduced.

In the study, as predicted, both groups showed a decrease in the alpha wave when they heard their names while awake. But high recallers showed a more prolonged decrease, which may be a sign their brains became more widely activated when they heard their names.

In other words, high recallers may engage more brain regions when processing sounds while awake, compared with low recallers, the researchers said.

While people are asleep, the alpha wave behaves in the opposite way —it increases when a sudden sound is heard. Scientists aren’t certain why this happens, but one idea is that it protects the brain from being interrupted by sounds during sleep, Ruby said.

Indeed, the study participants showed an increase in the alpha wave in response to sounds during sleep, and there was no difference between the groups.

One possibility to explain the lack of difference, the researchers said, could be that perhaps high recallers had a larger increase in alpha waves, but it was so high that they woke up.

Time spent awake, during the night

The researchers saw that high recallers awoke more frequently during the night. They were awake, on average, for 30 minutes during the night, whereas low recallers were awake for 14 minutes. However, Ruby said “both figures are in the normal range, it’s not that there’s something wrong with either group.”

Altogether, the results suggest the brain of high recallers may be more reactive to stimuli such as sounds, which could make them wake up more easily. It is more likely a person would remember their dreams if they are awakened immediately after one, Ruby said.

However, waking up at night can account for only a part of the differences people show in remembering dreams. “There’s still much more to understand,” she said.

The study is published online (Aug. 13) in the journal Frontiers in Psychology.

Filed under sleep dreaming brainwaves memory psychology neuroscience science

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MR images showing a patient with recurrent glioblastoma responding to anti-angiogenic therapy by reduction on abnormal tumor vessel calibers and a change in the direction of the vessel vortex curve estimated from a combined gradient-echo (GE) and spin-echo (SE) MR signal readout. The change from a predominantly counter-clockwise vessel vortex direction at baseline (days -5 and -1) to a predominantly clockwise vessel vortex direction during anti-angiogenic therapy (days 1, 28, 56 and 112) indicates a dramatic transformation in vascular morphology during anti-angiogenic therapy and resulting in increased overall survival. Credit: Kyrre E. Emblem New MR analysis technique reveals brain tumor response to anti-angiogenesis therapy A new way of analyzing data acquired in MR imaging appears to be able to identify whether or not tumors are responding to anti-angiogenesis therapy, information that can help physicians determine the most appropriate treatments and discontinue ones that are ineffective. In their report receiving online publication in Nature Medicine, investigators from the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH), describe how their technique, called vessel architectural imaging (VAI), was able to identify changes in brain tumor blood vessels within days of the initiation of anti-angiogenesis therapy. "Until now the only ways of obtaining similar data on the blood vessels in patients’ tumors were either taking a biopsy, which is a surgical procedure that can harm the patients and often cannot be repeated, or PET scanning, which provides limited information and exposes patients to a dose of radiation,” says Kyrre Emblem, PhD, of the Martinos Center, lead and corresponding author of the report. “VAI can acquire all of this information in a single MR exam that takes less than two minutes and can be safely repeated many times.” Previous studies in animals and in human patients have shown that the ability of anti-angiogenesis drugs to improve survival in cancer therapy stems from their ability to “normalize” the abnormal, leaky blood vessels that usually develop in a tumor, improving the perfusion of blood throughout a tumor and the effectiveness of chemotherapy and radiation. In the deadly brain tumor glioblastoma, MGH investigators found that anti-angiogenesis treatment alone significantly extends the survival of some patients by reducing edema, the swelling of brain tissue. In the current report, the MGH team uses VAI to investigate how these drugs produce their effects and which patients benefit. Advanced MR techniques developed in recent years can determine factors like the size, radius and capacity of blood vessels. VAI combines information from two types of advanced MR images and analyzes them in a way that distinguishes among small arteries, veins and capillaries; determines the radius of these vessels and shows how much oxygen is being delivered to tissues. The MGH team used VAI to analyze MR data acquired in a phase 2 clinical trial – led by Tracy Batchelor, MD, director of Pappas Center for Neuro-Oncology at MGH and a co-author of the current paper – of the anti-angiogenesis drug cediranib in patients with recurrent glioblastoma. The images had been taken before treatment started and then 1, 28, 56, and 112 days after it was initiated. In some patients, VAI identified changes reflecting vascular normalization within the tumors – particularly changes in the shape of blood vessels – after 28 days of cediranib therapy and sometimes as early as the next day. Of the 30 patients whose data was analyzed, VAI indicated that 10 were true responders to cediranib, whereas 12 who had a worsening of disease were characterized as non-responders. Data from the remaining 8 patients suggested stabilization of their tumors. Responding patients ended up surviving six months longer than non-responders, a significant difference for patients with an expected survival of less than two years, Emblem notes. He adds that quickly identifying those whose tumors don’t respond would allow discontinuation of the ineffective therapy and exploration of other options. Gregory Sorensen, MD, senior author of the Nature Medicine report, explains, “One of the biggest problems in cancer today is that we do not know who will benefit from a particular drug. Since only about half the patients who receive a typical anti-cancer drug benefit and the others just suffer side effects, knowing whether or not a patient’s tumor is responding to a drug can bring us one step closer to truly personalized medicine – tailoring therapies to the patients who will benefit and not wasting time and resources on treatments that will be ineffective.” Formerly with the Martinos Center, Sorensen is now with Siemens Healthcare. Study co-author Rakesh Jain, PhD, director of the Steele Laboratory in the MGH Department of Radiation Oncology, adds, “This is the most compelling evidence yet of vascular normalization with anti-angiogenic therapy in cancer patients and how this concept can be used to select patients likely to benefit from these therapies.” Lead author Emblem notes that VAI may help further improve understanding of how abnormal tumor blood vessels change during anti-angiogenesis treatment and could be useful in the treatment of other types of cancer and in vascular conditions like stroke. He and his colleagues are also exploring whether VAI can identify which glioblastoma patients are likely to respond to anti-angiogenesis drugs even before therapy is initiated, potentially eliminating treatment destined to be ineffective. A postdoctoral research fellow at the Martinos Center at the time of the study, Emblem is now a principal investigator at Oslo University Hospital in Norway and maintains an affiliation with the Martinos Center.

MR images showing a patient with recurrent glioblastoma responding to anti-angiogenic therapy by reduction on abnormal tumor vessel calibers and a change in the direction of the vessel vortex curve estimated from a combined gradient-echo (GE) and spin-echo (SE) MR signal readout. The change from a predominantly counter-clockwise vessel vortex direction at baseline (days -5 and -1) to a predominantly clockwise vessel vortex direction during anti-angiogenic therapy (days 1, 28, 56 and 112) indicates a dramatic transformation in vascular morphology during anti-angiogenic therapy and resulting in increased overall survival. Credit: Kyrre E. Emblem

New MR analysis technique reveals brain tumor response to anti-angiogenesis therapy

A new way of analyzing data acquired in MR imaging appears to be able to identify whether or not tumors are responding to anti-angiogenesis therapy, information that can help physicians determine the most appropriate treatments and discontinue ones that are ineffective. In their report receiving online publication in Nature Medicine, investigators from the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH), describe how their technique, called vessel architectural imaging (VAI), was able to identify changes in brain tumor blood vessels within days of the initiation of anti-angiogenesis therapy.

"Until now the only ways of obtaining similar data on the blood vessels in patients’ tumors were either taking a biopsy, which is a surgical procedure that can harm the patients and often cannot be repeated, or PET scanning, which provides limited information and exposes patients to a dose of radiation,” says Kyrre Emblem, PhD, of the Martinos Center, lead and corresponding author of the report. “VAI can acquire all of this information in a single MR exam that takes less than two minutes and can be safely repeated many times.”

Previous studies in animals and in human patients have shown that the ability of anti-angiogenesis drugs to improve survival in cancer therapy stems from their ability to “normalize” the abnormal, leaky blood vessels that usually develop in a tumor, improving the perfusion of blood throughout a tumor and the effectiveness of chemotherapy and radiation. In the deadly brain tumor glioblastoma, MGH investigators found that anti-angiogenesis treatment alone significantly extends the survival of some patients by reducing edema, the swelling of brain tissue. In the current report, the MGH team uses VAI to investigate how these drugs produce their effects and which patients benefit.

Advanced MR techniques developed in recent years can determine factors like the size, radius and capacity of blood vessels. VAI combines information from two types of advanced MR images and analyzes them in a way that distinguishes among small arteries, veins and capillaries; determines the radius of these vessels and shows how much oxygen is being delivered to tissues. The MGH team used VAI to analyze MR data acquired in a phase 2 clinical trial – led by Tracy Batchelor, MD, director of Pappas Center for Neuro-Oncology at MGH and a co-author of the current paper – of the anti-angiogenesis drug cediranib in patients with recurrent glioblastoma. The images had been taken before treatment started and then 1, 28, 56, and 112 days after it was initiated.

In some patients, VAI identified changes reflecting vascular normalization within the tumors – particularly changes in the shape of blood vessels – after 28 days of cediranib therapy and sometimes as early as the next day. Of the 30 patients whose data was analyzed, VAI indicated that 10 were true responders to cediranib, whereas 12 who had a worsening of disease were characterized as non-responders. Data from the remaining 8 patients suggested stabilization of their tumors. Responding patients ended up surviving six months longer than non-responders, a significant difference for patients with an expected survival of less than two years, Emblem notes. He adds that quickly identifying those whose tumors don’t respond would allow discontinuation of the ineffective therapy and exploration of other options.

Gregory Sorensen, MD, senior author of the Nature Medicine report, explains, “One of the biggest problems in cancer today is that we do not know who will benefit from a particular drug. Since only about half the patients who receive a typical anti-cancer drug benefit and the others just suffer side effects, knowing whether or not a patient’s tumor is responding to a drug can bring us one step closer to truly personalized medicine – tailoring therapies to the patients who will benefit and not wasting time and resources on treatments that will be ineffective.” Formerly with the Martinos Center, Sorensen is now with Siemens Healthcare.

Study co-author Rakesh Jain, PhD, director of the Steele Laboratory in the MGH Department of Radiation Oncology, adds, “This is the most compelling evidence yet of vascular normalization with anti-angiogenic therapy in cancer patients and how this concept can be used to select patients likely to benefit from these therapies.”

Lead author Emblem notes that VAI may help further improve understanding of how abnormal tumor blood vessels change during anti-angiogenesis treatment and could be useful in the treatment of other types of cancer and in vascular conditions like stroke. He and his colleagues are also exploring whether VAI can identify which glioblastoma patients are likely to respond to anti-angiogenesis drugs even before therapy is initiated, potentially eliminating treatment destined to be ineffective. A postdoctoral research fellow at the Martinos Center at the time of the study, Emblem is now a principal investigator at Oslo University Hospital in Norway and maintains an affiliation with the Martinos Center.

Filed under brain tumor anti-angiogenesis therapy glioblastoma blood vessels medicine neuroscience science

92 notes

Researchers Gain Insight into How Ion Channels Control Heart and Brain Electrical Activity Virginia Commonwealth University researchers studying a special class of potassium channels known as GIRKs, which serve important functions in heart and brain tissue, have revealed how they become activated to control cellular excitability. The findings advance the understanding of the interaction between a family of signaling proteins called G proteins, and a special type of cell membrane ion pore called G protein-sensitive, inwardly rectifying potassium (GIRK) channels. The findings may one day help researchers develop targeted drugs to treat conditions of the heart such as atrial fibrillation. In the study, published this week in the Online First section of Science Signaling, a publication of the American Association for the Advancement of Science (AAAS), researchers used a computational approach to predict the interactions between G proteins and a GIRK channel. Rahul Mahajan, a M.D./Ph.D. candidate in the VCU School of Medicine’s Department of Physiology and Biophysics, undertook this problem for his dissertation work, under the mentorship of Diomedes E. Logothetis, Ph.D., chair of the Department of Physiology and Biophysics and the John D. Bower Endowed Chair in Physiology in the VCU School of Medicine. They developed a model and tested its predictions in cells, demonstrating how G proteins cause activation of GIRKs.   “Malfunctions of GIRK channels have been implicated in chronic atrial fibrillation, as well as in drug abuse and addiction,” said Logothetis, who is an internationally recognized leader in the study of ion channels and cell signaling mechanisms.   “Understanding the structural mechanism of Gβγ activation of GIRK channels could lead to rational based drug design efforts to combat chronic atrial fibrillation.” In chronic atrial fibrillation, the GIRK channel is believed to be inappropriately open. According to Logothetis, if researchers are able to target only the specific site that keeps the channel inappropriately open, then any unrelated channels could be left unaltered, thus avoiding unwanted side effects. Crystal structures of GIRK channels, which preceded the current study, have revealed two constrictions of the ion permeation pathway that researchers call “gates”: one at the inner leaflet of the membrane bilayer and the other close by in the cytosol, which is the liquid found inside cells.   “The structure of the Gβγ -GIRK1 complex reveals that Gβγ inserts a part of it in a cleft formed by two cytosolic loops of two adjacent channel subunits,” Logothetis said. “This is also the place where alcohols bind to activate the channel. One can think of this cleft as a clam that has its shells either open or shut closed. Stabilization of this cleft in the ‘open’ position stabilizes the cytosolic gate in the open state.” GIRKs are activated when they interact with G proteins coupled to receptors bound to stimulatory hormones or neurotransmitters. In heart tissue, acetylcholine released by the vagus nerve activates these channels, which hyperpolarize the membrane potential and slow heart rate. In brain tissue, GIRKs inhibit excitation by acting at postsynaptic cells.   G proteins are composed of three subunits, a, b, and g. Since 1987, researchers have known that the Gbgsubunits directly activate the atrial GIRK channel, but an atomic resolution picture of how the two proteins interact remained elusive until now. Moving forward, the team would like to use computational and experimental approaches to build and test the structures of the rest of the components of the G protein complex – for example, the Ga subunits and the G protein-coupled receptor – around the Gβγ-channel complex, which is the structure the team has already achieved.

Researchers Gain Insight into How Ion Channels Control Heart and Brain Electrical Activity

Virginia Commonwealth University researchers studying a special class of potassium channels known as GIRKs, which serve important functions in heart and brain tissue, have revealed how they become activated to control cellular excitability.

The findings advance the understanding of the interaction between a family of signaling proteins called G proteins, and a special type of cell membrane ion pore called G protein-sensitive, inwardly rectifying potassium (GIRK) channels. The findings may one day help researchers develop targeted drugs to treat conditions of the heart such as atrial fibrillation.

In the study, published this week in the Online First section of Science Signaling, a publication of the American Association for the Advancement of Science (AAAS), researchers used a computational approach to predict the interactions between G proteins and a GIRK channel.

Rahul Mahajan, a M.D./Ph.D. candidate in the VCU School of Medicine’s Department of Physiology and Biophysics, undertook this problem for his dissertation work, under the mentorship of Diomedes E. Logothetis, Ph.D., chair of the Department of Physiology and Biophysics and the John D. Bower Endowed Chair in Physiology in the VCU School of Medicine. They developed a model and tested its predictions in cells, demonstrating how G proteins cause activation of GIRKs.  

“Malfunctions of GIRK channels have been implicated in chronic atrial fibrillation, as well as in drug abuse and addiction,” said Logothetis, who is an internationally recognized leader in the study of ion channels and cell signaling mechanisms.  

“Understanding the structural mechanism of Gβγ activation of GIRK channels could lead to rational based drug design efforts to combat chronic atrial fibrillation.”

In chronic atrial fibrillation, the GIRK channel is believed to be inappropriately open. According to Logothetis, if researchers are able to target only the specific site that keeps the channel inappropriately open, then any unrelated channels could be left unaltered, thus avoiding unwanted side effects.

Crystal structures of GIRK channels, which preceded the current study, have revealed two constrictions of the ion permeation pathway that researchers call “gates”: one at the inner leaflet of the membrane bilayer and the other close by in the cytosol, which is the liquid found inside cells.  

“The structure of the Gβγ -GIRK1 complex reveals that Gβγ inserts a part of it in a cleft formed by two cytosolic loops of two adjacent channel subunits,” Logothetis said. “This is also the place where alcohols bind to activate the channel. One can think of this cleft as a clam that has its shells either open or shut closed. Stabilization of this cleft in the ‘open’ position stabilizes the cytosolic gate in the open state.”

GIRKs are activated when they interact with G proteins coupled to receptors bound to stimulatory hormones or neurotransmitters. In heart tissue, acetylcholine released by the vagus nerve activates these channels, which hyperpolarize the membrane potential and slow heart rate. In brain tissue, GIRKs inhibit excitation by acting at postsynaptic cells.  

G proteins are composed of three subunits, a, b, and g. Since 1987, researchers have known that the Gbgsubunits directly activate the atrial GIRK channel, but an atomic resolution picture of how the two proteins interact remained elusive until now.

Moving forward, the team would like to use computational and experimental approaches to build and test the structures of the rest of the components of the G protein complex – for example, the Ga subunits and the G protein-coupled receptor – around the Gβγ-channel complex, which is the structure the team has already achieved.

Filed under ion channels potassium channels G proteins heart brain medicine neuroscience science

801 notes

8-Year-Old Never Ages, Could Reveal ‘Biological Immortality’ Gabby Williams has the facial features and skin of a newborn, and she is just as dependent. Her mother feeds, diapers and cradles her tiny frame as she did the day she was born. The little girl from Billings, Mont., is 8 years old, but weighs only 11 pounds. Gabby has a mysterious condition, shared by only a handful of others in the world, that slows her rate of aging. For the past two years, a doctor who has been trying to find the genetic off-switch to stop the aging process has been studying Gabby, as well as two other people who have striking similarities. Why the ‘Benjamin Button’ children never age. A 29-year-old Florida man has the body of a 10-year-old, and a 31-year-old Brazilian woman is the size of a 2-year-old. Like Gabby, neither seems to grow older. Unraveling what these three people may have in common is the subject of a TLC television special, “40-Year-Old Child: A New Case,” which airs Monday, Aug. 19, at 10 p.m. ET. The show is a follow-up to Gabby’s story, which aired last year. "In some people, something happens to them and the development process is retarded," said medical researcher Richard F. Walker. "The rate of change in the body slows and is negligible." 16-year-old is the size of a toddler. Walker is retired from the University of Florida Medical School and now does his research at All Children’s Hospital in St. Petersburg. "My whole career has been focused on the aging process," he told ABCNews.com. "My fixation has been not on the consequences but the cause of it." Not only do the people he’s studying have a growth rate of one-fifth the speed of others, but they live with a variety of other medical problems, including deafness, the inability to walk, eat or even speak. "Gabrielle hasn’t changed since pretty much forever," said her mother, Mary Margret Williams, 38. "She has gotten a little longer and we have jumped into putting her in size 3-6 month clothes instead of 0-3 months for the footies. "Last time we weighed her she was up a pound to 11 pounds and she’s gotten a few more haircuts," she told ABCNews.com. "Other than that, she hasn’t changed much since the [2012] show." Williams, who works part-time at a dermatologist’s office, and her husband, a corrections officer for the state, share the child care responsibilities for their perpetual infant. Walker explains that physiological change, or what he calls “developmental inertia,” is essential for human growth. Maturation occurs after reproduction. "Without that process we never develop," he said. "When we develop, all the pieces of our body come together and change and are coordinated. Otherwise, there would be chaos." But, said Walker, the body does not have a “stop switch” for this development. “What happens is we become mature at age 20 and continue to change.” The first subtle internal body changes of aging are seen in the 30s and become more visible in the 40s. "There is a progressive erosion of internal order as a result of developmental inertia," he said. In one of the girls Walker has studied, he found damage to one of the genes that causes developmental inertia, a finding that he said is significant. He also suspects the mutations are on the regulatory genes on the second female X chromosome. "If we could identify the gene and then at young adulthood we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal." Now Walker doesn’t mean that people will never die. Disease and accidents will still end human life. "But you wouldn’t have the later years — you’d remain physically and functionally able," he said. That is why he believes his study of Gabby Williams’ genetic code is so important. “She fits the model,” said Walker. "We’ve been on this journey to find out, are my other children at any risk in having a child like Gabrielle," said Williams, who has five other children between the ages of 1 and 10. "We did find out with Dr. Walker when he did the [gene] sequencing that it’s not something we can pass on but just an abnormality, a mutated gene that was just happenstance," she said. "That was a relief for us." At first, when the Williams family members found out about Walker’s research, they hesitated to become guinea pigs in the studies that would promote a so-called “fountain of youth.” "There was some concern," she said. "We are good Catholics, God-fearing people and we believe we are meant to get old — the process of life — and meant to die. It was scary to think about, and we did not want to be part of it." But as they talked further with Walker, the family realized that his research was designed to help people struggling with the impairments of old age. "Alzheimer’s is one of the scariest diseases out there," said Williams. "If what Gabrielle holds inside of her would find a cure — for sure we would be a part of the research project. We have faith that Dr. Walker and the scientific community do find something focused more on the disease of aging, rather than making you 35 for the rest of your life." As for Gabby’s life span, her doctors cannot say what that will look like. "From the time of her birth, we didn’t think she would be with us very long," said her mother. "The fact is she is now going on 9 years. She kind of surpassed my expectations from the get go. "It’s not something I worry about," said Williams, who said she trusts that God has a plan for her infantile daughter. "When he is ready to take her back, it will be sad," she said. "But what a glorious thing it will be for Gabby to go to heaven one day. I know it will happen, but I am not hoping it’s any day soon."

8-Year-Old Never Ages, Could Reveal ‘Biological Immortality’

Gabby Williams has the facial features and skin of a newborn, and she is just as dependent. Her mother feeds, diapers and cradles her tiny frame as she did the day she was born.

The little girl from Billings, Mont., is 8 years old, but weighs only 11 pounds. Gabby has a mysterious condition, shared by only a handful of others in the world, that slows her rate of aging.

For the past two years, a doctor who has been trying to find the genetic off-switch to stop the aging process has been studying Gabby, as well as two other people who have striking similarities.

Why the ‘Benjamin Button’ children never age.

A 29-year-old Florida man has the body of a 10-year-old, and a 31-year-old Brazilian woman is the size of a 2-year-old. Like Gabby, neither seems to grow older.

Unraveling what these three people may have in common is the subject of a TLC television special, “40-Year-Old Child: A New Case,” which airs Monday, Aug. 19, at 10 p.m. ET. The show is a follow-up to Gabby’s story, which aired last year.

"In some people, something happens to them and the development process is retarded," said medical researcher Richard F. Walker. "The rate of change in the body slows and is negligible."

16-year-old is the size of a toddler.

Walker is retired from the University of Florida Medical School and now does his research at All Children’s Hospital in St. Petersburg.

"My whole career has been focused on the aging process," he told ABCNews.com. "My fixation has been not on the consequences but the cause of it."

Not only do the people he’s studying have a growth rate of one-fifth the speed of others, but they live with a variety of other medical problems, including deafness, the inability to walk, eat or even speak.

"Gabrielle hasn’t changed since pretty much forever," said her mother, Mary Margret Williams, 38. "She has gotten a little longer and we have jumped into putting her in size 3-6 month clothes instead of 0-3 months for the footies.

"Last time we weighed her she was up a pound to 11 pounds and she’s gotten a few more haircuts," she told ABCNews.com. "Other than that, she hasn’t changed much since the [2012] show."

Williams, who works part-time at a dermatologist’s office, and her husband, a corrections officer for the state, share the child care responsibilities for their perpetual infant.

Walker explains that physiological change, or what he calls “developmental inertia,” is essential for human growth. Maturation occurs after reproduction.

"Without that process we never develop," he said. "When we develop, all the pieces of our body come together and change and are coordinated. Otherwise, there would be chaos."

But, said Walker, the body does not have a “stop switch” for this development. “What happens is we become mature at age 20 and continue to change.”

The first subtle internal body changes of aging are seen in the 30s and become more visible in the 40s.

"There is a progressive erosion of internal order as a result of developmental inertia," he said.

In one of the girls Walker has studied, he found damage to one of the genes that causes developmental inertia, a finding that he said is significant. He also suspects the mutations are on the regulatory genes on the second female X chromosome.

"If we could identify the gene and then at young adulthood we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal."

Now Walker doesn’t mean that people will never die. Disease and accidents will still end human life.

"But you wouldn’t have the later years — you’d remain physically and functionally able," he said.

That is why he believes his study of Gabby Williams’ genetic code is so important. “She fits the model,” said Walker.

"We’ve been on this journey to find out, are my other children at any risk in having a child like Gabrielle," said Williams, who has five other children between the ages of 1 and 10.

"We did find out with Dr. Walker when he did the [gene] sequencing that it’s not something we can pass on but just an abnormality, a mutated gene that was just happenstance," she said. "That was a relief for us."

At first, when the Williams family members found out about Walker’s research, they hesitated to become guinea pigs in the studies that would promote a so-called “fountain of youth.”

"There was some concern," she said. "We are good Catholics, God-fearing people and we believe we are meant to get old — the process of life — and meant to die. It was scary to think about, and we did not want to be part of it."

But as they talked further with Walker, the family realized that his research was designed to help people struggling with the impairments of old age.

"Alzheimer’s is one of the scariest diseases out there," said Williams. "If what Gabrielle holds inside of her would find a cure — for sure we would be a part of the research project. We have faith that Dr. Walker and the scientific community do find something focused more on the disease of aging, rather than making you 35 for the rest of your life."

As for Gabby’s life span, her doctors cannot say what that will look like.

"From the time of her birth, we didn’t think she would be with us very long," said her mother. "The fact is she is now going on 9 years. She kind of surpassed my expectations from the get go.

"It’s not something I worry about," said Williams, who said she trusts that God has a plan for her infantile daughter.

"When he is ready to take her back, it will be sad," she said. "But what a glorious thing it will be for Gabby to go to heaven one day. I know it will happen, but I am not hoping it’s any day soon."

Filed under progeria aging developmental inertia genetics neuroscience science

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Why One Cream Cake Leads to Another

Continuously eating fatty foods perturbs communication between the gut and brain, which in turn perpetuates a bad diet.

A chronic high-fat diet is thought to desensitize the brain to the feeling of satisfaction that one normally gets from a meal, causing a person to overeat in order to achieve the same high again. New research published today (August 15) in Science, however, suggests that this desensitization actually begins in the gut itself, where production of a satiety factor, which normally tells the brain to stop eating, becomes dialed down by the repeated intake of high-fat food.

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“It’s really fantastic work,” said Paul Kenny, a professor of molecular therapeutics at The Scripps Research Institute in Jupiter, Florida, who was not involved in the study. “It could be a so-called missing link between gut and brain signaling, which has been something of a mystery.”

While pork belly, ice cream, and other high-fat foods produce an endorphin response in the brain when they hit the taste buds, according to Kenny, the gut also sends signals directly to the brain to control our feeding behavior. Indeed, mice nourished via gastric feeding tubes, which bypass the mouth, exhibit a surge in dopamine—a neurotransmitter promoting reinforcement in the brain’s reward circuitry—similar to that experienced by those eating normally.

This dopamine surge occurs in response to feeding in both mice and humans. But evidence suggests that dopamine signaling in the brain is deficient in obese people. Ivan de Araujo, a professor of psychiatry at the Yale School of Medicine, has now discovered that obese mice on a chronic high-fat diet also have a muted dopamine response when receiving fatty food via a direct tube to their stomachs.

To determine the nature of the dopamine-regulating signal emanating from the gut, Araujo and his team searched for possible candidates. “When you look at animals chronically exposed to high-fat foods, you see high levels of almost every circulating factor—leptin, insulin, triglycerides, glucose, et cetera,” he said. But one class of signaling molecule is suppressed. Of these, Araujo’s primary candidate was oleoylethanolamide. Not only is the factor produced by intestinal cells in response to food, he said, but during chronic high-fat exposure, “the suppression levels seemed to somehow match the suppression that we saw in dopamine release.”

Araujo confirmed oleoylethanol’s dopamine-regulating ability in mice by administering the factor via a catheter to the tissues surrounding their guts. “We discovered that by restoring the baseline level of [oleoylethanolamide] in the gut … the high-fat fed animals started having dopamine responses that were indistinguishable from their lean counterparts.”

The team also found that oleoylethanolamide’s effect on dopamine was transmitted via the vagus nerve, which runs between the brain and abdomen, and was dependent on its interaction with a transcription factor called PPAR-a.

Oleoylethanolamide levels are also reduced in fasting animals and increase in response to eating, communicating with the brain to stop further consumption once the belly is full. Indeed, oleoylethanolamide is a known satiety factor. Therefore, when chronic consumption of high-fat food diminishes its production, the satisfaction signal is not achieved, and the brain is essentially “blind to the presence of calories in the gut,” said Araujo, and thus demands more food.

It is not clear why a chronic high-fat diet suppresses the production of oleoylethanolamide. But once the vicious cycle starts, it is hard to break because the brain is receiving its information subconsciously, said Daniele Piomelli, a professor at the University of California, Irvine, and director of drug discovery and development at the Italian Institute of Technology in Genoa.

“We eat what we like, and we think we are conscious of what we like, but I think what this [paper] and others are indicating is that there is a deeper, darker side to liking—a side that we’re not aware of,” Piomelli said. “Because it is an innate drive, you can not control it.” Put another way, even if you could trick your taste buds into enjoying low-fat yogurt, you’re unlikely to trick your gut.

The good news, however, is that “there is no permanent impairment in the [animals’] dopamine levels,” Araujo said. This suggests that if drugs could be designed to regulate the oleoylethanolamide–to-PPAR-a pathway in the gut, Kenny added, it could have “a huge impact on people’s ability to control their appetite.”

(Source: the-scientist.com)

Filed under dopamine dopamine deficiency obesity diet appetite neuroscience science

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Head hurts? Zap the wonder nerve in your neck

"It was like red-hot pokers needling one side of my face," says Catherine, recalling the cluster headaches she experienced for six years. "I just wanted it to stop." But it wouldn’t – none of the drugs she tried had any effect.

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Thinking she had nothing to lose, last year she enrolled in a pilot study to test a handheld device that applies a bolt of electricity to the neck, stimulating the vagus nerve – the superhighway that connects the brain to many of the body’s organs, including the heart.

The results of the trial were presented last month at the International Headache Congress in Boston, and while the trial is small, the findings are positive. Of the 21 volunteers, 18 reported a reduction in the severity and frequency of their headaches, rating them, on average, 50 per cent less painful after using the device daily and whenever they felt a headache coming on.

This isn’t the first time vagal nerve stimulation has been used as a treatment – but it is one of the first that hasn’t required surgery. Some people with epilepsy have had a small generator that sends regular electrical signals to the vagus nerve implanted into their chest. Implanted devices have also been approved to treat depression. What’s more, there is increasing evidence that such stimulation could treat many more disorders from headaches to stroke and possibly Alzheimer’s disease.

The latest study suggests it is possible to stimulate the nerve through the skin, rather than resorting to surgery. “What we’ve done is figured out a way to stimulate the vagus nerve with a very similar signal, but non-invasively through the neck,” says Bruce Simon, vice-president of research at New Jersey-based ElectroCore, makers of the handheld device. “It’s a simpler, less invasive way to stimulate the nerve.”

Cluster headaches are thought to be triggered by the overactivation of brain cells involved in pain processing. The neurotransmitter glutamate, which excites brain cells, is a prime suspect. ElectroCore turned to the vagus nerve as previous studies had shown that stimulating it in people with epilepsy releases neurotransmitters that dampen brain activity.

When the firm used a smaller version of ElectroCore’s device on rats, it found it reduced glutamate levels and excitability in these pain centres. Other studies have shown that vagus nerve stimulation causes the release of inhibitory neurotransmitters which counter the effects of glutamate.

The big question is whether a non-implantable device can really trigger changes in brain chemistry in humans, or whether people are simply experiencing a placebo effect. “The vagus nerve is buried deep in the neck, and something that’s delivering currents through the skin can only go so deep,” says Mike Kilgard of the University of Texas at Dallas. As you turn up the voltage, there’s a risk of it activating muscle fibres that trigger painful cramps, he adds.

Simon says that volunteers using the device haven’t reported any serious side effects. He adds that ElectroCore will soon publish data showing changes in brain activity in humans after using the device. Placebo-controlled trials are also about to start.

Catherine has been using it for a year without ill effect. “I can now function properly as a human being again,” she says.

The many uses of the wonder nerve

Coma, irritable bowel syndrome, asthma and obesity are just some of the disparate conditions that vagus nerve stimulation may benefit and for which human trials are under way.

It might also help people with tinnitus. Although people with tinnitus complain of ringing in their ears, the problem actually arises because too many neurons fire in the auditory part of the brain when certain frequencies are heard.

Mike Kilgard of the University of Texas at Dallas reasoned that if people were played tones that didn’t trigger tinnitus while the vagus nerve was stimulated, this might coax the rogue neurons into firing in response to these frequencies instead. “By activating this nerve we can enhance the brain’s ability to rewire itself,” he says.

He has so far tested the method in rats and in 10 people with tinnitus, using an implanted device to stimulate the nerve. Not everyone noticed an improvement, but even so Kilgard is planning a larger trial. The work was presented at a meeting of the International Union of Physiological Sciences in Birmingham, UK, last month. The technique is also being tested in people who have had a stroke.

"If these studies stand up it could be worth changing the name of the vagus nerve to the wonder nerve," says Sunny Ogbonnaya at Cork University Hospital in Ireland.

Filed under vagus nerve vagal nerve stimulation glutamate headaches brain activity neuroscience science

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Device Could Spot Seizures by Reading Brainwaves through the Ear

Neuroscientists often use electroencephalography (EEG) as an inexpensive way to record electrical signals in the brain. Though it would be useful to run these recordings for long periods of time, that usually isn’t practical: EEG recording traditionally involves attaching many electrodes and cables to a patient’s scalp.

Now engineers at Imperial College in London have developed an EEG device that can be worn inside the ear, like a hearing aid. They say the device will allow scientists to record EEGs for several days at a time; this would allow doctors to monitor patients who have regularly recurring problems like seizures or microsleep.

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“The ideal is to have a very stable recording system, and recordings which are repeatable,” explains co-creator Danilo Mandic. “It’s not interfering with your normal life, because there are acoustic vents so people can hear. After a while, they forget they’re having an EEG.”

By nestling the EEG inside the ear, the engineers avoid a lot of signal noise usually introduced by body movement. They can also ensure that the electrodes are always placed in exactly the same spot, which, they say, will make repeated readings more reliable.

Since the device attaches to just one area, it can record only from the temporal region. This limits its potential applications to events that involve local activity. Tzzy-Ping Jung, co-director of the University of California, San Diego’s Center for Advanced Neurological Engineering, says that this does not mean the device will not be valuable.

“Different modalities will have different applications. I would not rule out the usefulness of any modalities,” says Jung. “I think it’s a very good idea with very promising results.”

(Source: technologyreview.com)

Filed under EEG device brain imaging seizures brainwaves neuroscience science

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Female frogs prefer males who can multitask

From frogs to humans, selecting a mate is complicated. Females of many species judge suitors based on many indicators of health or parenting potential. But it can be difficult for males to produce multiple signals that demonstrate these qualities simultaneously.

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In a study of gray tree frogs, a team of University of Minnesota researchers discovered that females prefer males whose calls reflect the ability to multitask effectively. In this species (Hyla chrysoscelis) males produce “trilled” mating calls that consist of a string of pulses.

Typical calls can range in duration from 20-40 pulses per call and occur between 5-15 calls per minute. Males face a trade-off between call duration and call rate, but females preferred calls that are longer and more frequent, which is no simple task.

The findings were published in August issue of Animal Behavior.

"It’s kind of like singing and dancing at the same time," says Jessica Ward, a postdoctoral researcher who is lead author for the study. Ward works in the laboratory of Mark Bee, a professor in the College of Biological Sciences’ Department of Ecology, Evolution and Behavior.

The study supports the multitasking hypothesis, which suggests that females prefer males who can do two or more hard-to-do things at the same time because these are especially good quality males, Ward says. The hypothesis, which explores how multiple signals produced by males influence female behavior, is a new area of interest in animal behavior research.

By listening to recordings of 1,000 calls, Ward and colleagues learned that males are indeed forced to trade off call duration and call rate. That is, males that produce relatively longer calls only do so at relatively slower rates.

"It’s easy to imagine that we humans might also prefer multitasking partners, such as someone who can successfully earn a good income, cook dinner, manage the finances and get the kids to soccer practice on time."

The study was carried out in connection with Bee’s research goal, which is understanding how female frogs are able to distinguish individual mating calls from a large chorus of males. By comparison, humans, especially as we age, lose the ability to distinguish individual voices in a crowd. This phenomenon, called the “cocktail party” problem, is often the first sign of a diminishing ability to hear. Understanding how frogs hear could lead to improved hearing aids.

(Source: www1.umn.edu)

Filed under multitasking mating frogs animal behavior psychology neuroscience science

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Autistic kids who best peers at math show different brain organization Children with autism and average IQs consistently demonstrated superior math skills compared with nonautistic children in the same IQ range, according to a study by researchers at the Stanford University School of Medicine and Lucile Packard Children’s Hospital. “There appears to be a unique pattern of brain organization that underlies superior problem-solving abilities in children with autism,” said Vinod Menon, PhD, professor of psychiatry and behavioral sciences and a member of the Child Health Research Institute at Packard Children’s. The autistic children’s enhanced math abilities were tied to patterns of activation in a particular area of their brains — an area normally associated with recognizing faces and visual objects. Menon is senior author of the study, published online Aug. 17 in Biological Psychiatry. Postdoctoral scholar Teresa luculano, PhD, is the lead author. Children with autism have difficulty with social interactions, especially interpreting nonverbal cues in face-to-face conversations. They often engage in repetitive behaviors and have a restricted range of interests. But in addition to such deficits, children with autism sometimes exhibit exceptional skills or talents, known as savant abilities. For example, some can instantly recall the day of the week of any calendar date within a particular range of years — for example, that May 21, 1982, was a Friday. And some display superior mathematical skills. “Remembering calendar dates is probably not going to help you with academic and professional success,” Menon said. “But being able to solve numerical problems and developing good mathematical skills could make a big difference in the life of a child with autism.” The idea that people with autism could employ such skills in jobs, and get satisfaction from doing so, has been gaining ground in recent years. The participants in the study were 36 children, ages 7 to 12. Half had been diagnosed with autism. The other half was the control group. Each group had 14 boys and four girls. (Autism disproportionately affects boys.) All participants had IQs in the normal range and showed normal verbal and reading skills on standardized tests administered as part of the recruitment process for the study. But on the standardized math tests that were administered, the children with autism outperformed children in the control group. After the math test, researchers interviewed the children to assess which types of problem-solving strategies each had used: Simply remembering an answer they already knew; counting on their fingers or in their heads; or breaking the problem down into components — a comparatively sophisticated method called decomposition. The children with autism displayed greater use of decomposition strategies, suggesting that more analytic strategies, rather than rote memory, were the source of their enhanced abilities. Then, the children worked on solving math problems while their brain activity was measured in an MRI scanner, in which they had to lie down and remain still. The brain scans of the autistic children revealed an unusual pattern of activity in the ventral temporal occipital cortex, an area specialized for processing visual objects, including faces. “Our findings suggest that altered patterns of brain organization in areas typically devoted to face processing may underlie the ability of children with autism to develop specialized skills in numerical problem solving,” Iuculano said. “These findings not only empirically confirm that high-functioning children with autism have especially strong number-problem-solving abilities, but show that this cognitive strength in math is based on different patterns of functional brain organization,” said Carl Feinstein, MD, director of the Center for Autism and Related Disorders at Packard Children’s and professor of psychiatry and behavioral sciences at the School of Medicine. He was not involved in the study. Menon added that previous research “has focused almost exclusively on weaknesses in children with autism. Our study supports the idea that the atypical brain development in autism can lead, not just to deficits, but also to some remarkable cognitive strengths. We think this can be reassuring to parents.” The research team is now gathering data from a larger group of children with autism to learn more about individual differences in their mathematical abilities. Menon emphasized that not all children with autism have superior math abilities, and that understanding the neural basis of variations in problem-solving abilities is an important topic for future research. (Image: Corbis)

Autistic kids who best peers at math show different brain organization

Children with autism and average IQs consistently demonstrated superior math skills compared with nonautistic children in the same IQ range, according to a study by researchers at the Stanford University School of Medicine and Lucile Packard Children’s Hospital.

“There appears to be a unique pattern of brain organization that underlies superior problem-solving abilities in children with autism,” said Vinod Menon, PhD, professor of psychiatry and behavioral sciences and a member of the Child Health Research Institute at Packard Children’s.

The autistic children’s enhanced math abilities were tied to patterns of activation in a particular area of their brains — an area normally associated with recognizing faces and visual objects.

Menon is senior author of the study, published online Aug. 17 in Biological Psychiatry. Postdoctoral scholar Teresa luculano, PhD, is the lead author.

Children with autism have difficulty with social interactions, especially interpreting nonverbal cues in face-to-face conversations. They often engage in repetitive behaviors and have a restricted range of interests.

But in addition to such deficits, children with autism sometimes exhibit exceptional skills or talents, known as savant abilities. For example, some can instantly recall the day of the week of any calendar date within a particular range of years — for example, that May 21, 1982, was a Friday. And some display superior mathematical skills.

“Remembering calendar dates is probably not going to help you with academic and professional success,” Menon said. “But being able to solve numerical problems and developing good mathematical skills could make a big difference in the life of a child with autism.”

The idea that people with autism could employ such skills in jobs, and get satisfaction from doing so, has been gaining ground in recent years.

The participants in the study were 36 children, ages 7 to 12. Half had been diagnosed with autism. The other half was the control group. Each group had 14 boys and four girls. (Autism disproportionately affects boys.) All participants had IQs in the normal range and showed normal verbal and reading skills on standardized tests administered as part of the recruitment process for the study. But on the standardized math tests that were administered, the children with autism outperformed children in the control group.

After the math test, researchers interviewed the children to assess which types of problem-solving strategies each had used: Simply remembering an answer they already knew; counting on their fingers or in their heads; or breaking the problem down into components — a comparatively sophisticated method called decomposition. The children with autism displayed greater use of decomposition strategies, suggesting that more analytic strategies, rather than rote memory, were the source of their enhanced abilities.

Then, the children worked on solving math problems while their brain activity was measured in an MRI scanner, in which they had to lie down and remain still. The brain scans of the autistic children revealed an unusual pattern of activity in the ventral temporal occipital cortex, an area specialized for processing visual objects, including faces.

“Our findings suggest that altered patterns of brain organization in areas typically devoted to face processing may underlie the ability of children with autism to develop specialized skills in numerical problem solving,” Iuculano said.

“These findings not only empirically confirm that high-functioning children with autism have especially strong number-problem-solving abilities, but show that this cognitive strength in math is based on different patterns of functional brain organization,” said Carl Feinstein, MD, director of the Center for Autism and Related Disorders at Packard Children’s and professor of psychiatry and behavioral sciences at the School of Medicine. He was not involved in the study.

Menon added that previous research “has focused almost exclusively on weaknesses in children with autism. Our study supports the idea that the atypical brain development in autism can lead, not just to deficits, but also to some remarkable cognitive strengths. We think this can be reassuring to parents.”

The research team is now gathering data from a larger group of children with autism to learn more about individual differences in their mathematical abilities. Menon emphasized that not all children with autism have superior math abilities, and that understanding the neural basis of variations in problem-solving abilities is an important topic for future research.

(Image: Corbis)

Filed under autism ASD mathematical skills brain differences brain activity neuroimaging neuroscience psychology science

162 notes

Remembering to Remember Supported by Two Distinct Brain Processes You plan on shopping for groceries later and you tell yourself that you have to remember to take the grocery bags with you when you leave the house. Lo and behold, you reach the check-out counter and you realize you’ve forgotten the bags. Remembering to remember — whether it’s grocery bags, appointments, or taking medications — is essential to our everyday lives. New research sheds light on two distinct brain processes that underlie this type of memory, known as prospective memory. The research is published in Psychological Science, a journal of the Association for Psychological Science. To investigate how prospective memory is processed in the brain, psychological scientist Mark McDaniel of Washington University in St. Louis and colleagues had participants lie in an fMRI scanner and asked them to press one of two buttons to indicate whether a  word that popped up on a screen was a member of a designated category. In addition to this ongoing activity, participants were asked to try to remember to press a third button whenever a special target popped up. The task was designed to tap into participants’ prospective memory, or their ability to remember to take certain actions in response to specific future events. When McDaniel and colleagues analyzed the fMRI data, they observed that two distinct brain activation patterns emerged when participants made the correct button press for a special target. When the special target was not relevant to the ongoing activity — such as a syllable like “tor” — participants seemed to rely on top-down brain processes supported by the prefrontal cortex. In order to answer correctly when the special syllable flashed up on the screen, the participants had to sustain their attention and monitor for the special syllable throughout the entire task. In the grocery bag scenario, this would be like remembering to bring the grocery bags by constantly reminding yourself that you can’t forget them. When the special target was integral to the ongoing activity—such as a whole word, like “table” — participants recruited a different set of brain regions, and they didn’t show sustained activation in these regions. The findings suggest that remembering what to do when the special target was a whole word didn’t require the same type of top-down monitoring. Instead, the target word seemed to act as an environmental cue that prompted participants to make the appropriate response – like reminding yourself to bring the grocery bags by leaving them near the front door. “These findings suggest that people could make use of several different strategies to accomplish prospective memory tasks,” says McDaniel. McDaniel and colleagues are continuing their research on prospective memory, examining how this phenomenon might change with age. (Image: Shutterstock)

Remembering to Remember Supported by Two Distinct Brain Processes

You plan on shopping for groceries later and you tell yourself that you have to remember to take the grocery bags with you when you leave the house. Lo and behold, you reach the check-out counter and you realize you’ve forgotten the bags.

Remembering to remember — whether it’s grocery bags, appointments, or taking medications — is essential to our everyday lives. New research sheds light on two distinct brain processes that underlie this type of memory, known as prospective memory.

The research is published in Psychological Science, a journal of the Association for Psychological Science.

To investigate how prospective memory is processed in the brain, psychological scientist Mark McDaniel of Washington University in St. Louis and colleagues had participants lie in an fMRI scanner and asked them to press one of two buttons to indicate whether a  word that popped up on a screen was a member of a designated category. In addition to this ongoing activity, participants were asked to try to remember to press a third button whenever a special target popped up. The task was designed to tap into participants’ prospective memory, or their ability to remember to take certain actions in response to specific future events.

When McDaniel and colleagues analyzed the fMRI data, they observed that two distinct brain activation patterns emerged when participants made the correct button press for a special target.

When the special target was not relevant to the ongoing activity — such as a syllable like “tor” — participants seemed to rely on top-down brain processes supported by the prefrontal cortex. In order to answer correctly when the special syllable flashed up on the screen, the participants had to sustain their attention and monitor for the special syllable throughout the entire task. In the grocery bag scenario, this would be like remembering to bring the grocery bags by constantly reminding yourself that you can’t forget them.

When the special target was integral to the ongoing activity—such as a whole word, like “table” — participants recruited a different set of brain regions, and they didn’t show sustained activation in these regions. The findings suggest that remembering what to do when the special target was a whole word didn’t require the same type of top-down monitoring. Instead, the target word seemed to act as an environmental cue that prompted participants to make the appropriate response – like reminding yourself to bring the grocery bags by leaving them near the front door.

“These findings suggest that people could make use of several different strategies to accomplish prospective memory tasks,” says McDaniel.

McDaniel and colleagues are continuing their research on prospective memory, examining how this phenomenon might change with age.

(Image: Shutterstock)

Filed under prospective memory fMRI brain activity prefrontal cortex memory psychology neuroscience science

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