Scientists have for the first time recorded individual brain cells in the act of summoning a spontaneous memory, revealing not only where a remembered experience is registered but also, in part, how the brain is able to recreate it.
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Showing posts with label brain. Show all posts
Showing posts with label brain. Show all posts
Wednesday, December 17, 2008
Tuesday, September 16, 2008
Thursday, August 14, 2008
Your living 1/10 of a second in the future!
Key to All Optical Illusions Discovered
Humans can see into the future, says a cognitive scientist. It's nothing like the alleged predictive powers of Nostradamus, but we do get a glimpse of events one-tenth of a second before they occur.
And the mechanism behind that can also explain why we are tricked by optical illusions.
Researcher Mark Changizi of Rensselaer Polytechnic Institute in New York says it starts with a neural lag that most everyone experiences while awake. When light hits your retina, about one-tenth of a second goes by before the brain translates the signal into a visual perception of the world.
Scientists already knew about the lag, yet they have debated over exactly how we compensate, with one school of thought proposing our motor system somehow modifies our movements to offset the delay.
Humans can see into the future, says a cognitive scientist. It's nothing like the alleged predictive powers of Nostradamus, but we do get a glimpse of events one-tenth of a second before they occur.
And the mechanism behind that can also explain why we are tricked by optical illusions.
Researcher Mark Changizi of Rensselaer Polytechnic Institute in New York says it starts with a neural lag that most everyone experiences while awake. When light hits your retina, about one-tenth of a second goes by before the brain translates the signal into a visual perception of the world.
Scientists already knew about the lag, yet they have debated over exactly how we compensate, with one school of thought proposing our motor system somehow modifies our movements to offset the delay.
Human brain appears 'hard-wired' for hierarchy
Human imaging studies have for the first time identified brain circuitry associated with social status, according to researchers at the National Institute of Mental Health (NIMH) of the National Institutes of Health. They found that different brain areas are activated when a person moves up or down in a pecking order – or simply views perceived social superiors or inferiors. Circuitry activated by important events responded to a potential change in hierarchical status as much as it did to winning money.
story
story
Coke versus Pepsi: It's all in the head
The preference for Coke versus Pepsi is not only a matter for the tongue to decide, Samuel McClure and his colleagues have found. Brain scans of people tasting the soft drinks reveal that knowing which drink they're tasting affects their preference and activates memory-related brain regions that recall cultural influences. Thus, say the researchers, they have shown neurologically how a culturally based brand image influences a behavioral choice.
story.
story.
Cognitive dissonance in monkeys
And Behind Door No. 1, a Fatal Flaw
By JOHN TIERNEY
Published: April 8, 2008
Some experiments that purport to show cognitive-dissonance effects might be explainable by statistics alone.
Not Really.
NY Times story.
By JOHN TIERNEY
Published: April 8, 2008
Some experiments that purport to show cognitive-dissonance effects might be explainable by statistics alone.
Not Really.
NY Times story.
Brain Scanners Can See Your Decisions Before You Make Them
You may think you decided to read this story -- but in fact, your brain made the decision long before you knew about it.
In a study published Sunday in Nature Neuroscience, researchers using brain scanners could predict people's decisions seven seconds before the test subjects were even aware of making them.
The decision studied -- whether to hit a button with one's left or right hand -- may not be representative of complicated choices that are more integrally tied to our sense of self-direction. Regardless, the findings raise profound questions about the nature of self and autonomy: How free is our will? Is conscious choice just an illusion?
Wired Story
In a study published Sunday in Nature Neuroscience, researchers using brain scanners could predict people's decisions seven seconds before the test subjects were even aware of making them.
The decision studied -- whether to hit a button with one's left or right hand -- may not be representative of complicated choices that are more integrally tied to our sense of self-direction. Regardless, the findings raise profound questions about the nature of self and autonomy: How free is our will? Is conscious choice just an illusion?
Wired Story
Saturday, June 14, 2008
What Women Want (Maybe)
What Women Want (Maybe)
By ANDY NEWMAN
Published: June 12, 2008
NY Times
A new documentary about bisexuality provides scientific evidence that places female sexuality along a continuum between heterosexuality and homosexuality, rather than as an either-or phenomenon.
This article cites JPSP research on images which arouse heterosexual women.
By ANDY NEWMAN
Published: June 12, 2008
NY Times
A new documentary about bisexuality provides scientific evidence that places female sexuality along a continuum between heterosexuality and homosexuality, rather than as an either-or phenomenon.
This article cites JPSP research on images which arouse heterosexual women.
Sunday, March 23, 2008
"ice-pick" lobotomy
On Jan. 17, 1946, a psychiatrist named Walter Freeman launched a radical new era in the treatment of mental illness in this country. On that day, he performed the first-ever transorbital or "ice-pick" lobotomy in his Washington, D.C., office. Freeman believed that mental illness was related to overactive emotions, and that by cutting the brain he cut away these feelings.
All Things Considered
All Things Considered
Sunday, February 24, 2008
Wednesday, February 20, 2008
Researchers Gain Understanding of How Poverty Alters the Brain
The Chronicle of Higher Education
Monday, February 18, 2008
Researchers Gain Understanding of How Poverty Alters the Brain
By RICHARD MONASTERSKY
Brain studies of poor children reveal that their neural systems develop differently from those of other children, a finding that potentially points the way toward creating methods for ameliorating the effects of poverty on academic achievement.
"Growing up poor is bad for your brain—we've known that for a long time," said Martha J. Farah, director of the center for cognitive neuroscience at the University of Pennsylvania. "What's new is that neuroscientists have begun to try to understand this problem," she said last week at the annual meeting here of the American Association for the Advancement of Science, which ends today.
For generations, psychologists have noted that children raised in poverty perform poorer on cognitive tests, on average, than do students from wealthier families. Some researchers have taken those results to argue that intelligence is determined for the most part by genetics and that certain races are inherently smarter than others. In 1994, Richard J. Herrnstein and Charles Murray presented that case in their book, The Bell Curve: Intelligence and Class Structure in American Life.
But the new results from neuroscience indicate that experience, especially being raised in poverty, has a strong effect on the way the brain works. "It's not a case of bad genes," said Ms. Farah.
She and her colleagues have investigated the issue by trying to tease out which aspects of poverty alter specific cognitive skills, such as memory, language, and the ability to delay gratification. The researchers studied a group of African-American children of low socioeconomic status, who had been tracked from birth through high-school graduation by Hallam Hurt, a pediatrician at Penn.
Over the years, Dr. Hurt's team had assessed the home environments of the children, monitoring how nurturing parents were, and how intellectually stimulating the homes were—for example, whether the children had access to books and visited museums.
When Ms. Farah's team tested 110 of those children, they found that particular cognitive skills were linked with certain aspects of the environment. Children with better language abilities were more likely to come from intellectually stimulating homes, no matter how nurturing their parents were. Memory skills, however, matched the nurturing levels in the home, reported Ms. Farah, who will publish her results in an upcoming issue of Developmental Science.
Effect of Nurturing on the Brain
To test why, the researchers did MRI scans of the children. They found that students raised in nurturing homes generally had bigger hippocampi, the portion of the brain associated with forming and retrieving memories. The discovery dovetails with previous research in rodents, which showed that rats raised in a stressful environment develop smaller hippocampi.
The results of the new work suggest that "it's worth making intervention and prevention programs because clearly a lot of the action here is experiential," said Ms. Farah. "This points out the fact that these phenomena are the result of adverse environments."
At the science association's meeting, Courtney Stevens, a postdoctoral research associate at the University of Oregon's brain-development laboratory, described other experiments on the cognitive effects of poverty. In one study, researchers put a net of electrodes on the heads of children and measured their brain waves. The children were seated between two speakers playing different stories and they were asked to pay attention to only one of the stories.
While the stories were being read, the children heard identical bursts of distracting noise coming from either of the speakers. The brains of the children responded differently to those same noises, depending on whether it came from the side they were listening to or ignoring. It's almost as if the brain has a volume control, turning up the sound on the side it is attending to, said Ms. Stevens.
The study revealed that students from lower-income families were less able to screen out the noises embedded in the stories they were supposed to ignore.
The students in the higher-income group, however, "had more gain on their volume control," she said. "Their brains were able to make a larger distinction between what they were trying to hear versus ignore."
With those results and others suggesting that cognitive skills are strongly influenced by environment, the Oregon team is developing intervention programs to try to counteract the effects of poverty. At the meeting, Ms. Courtney described one experimental program that has shown initial success.
Parental-Intervention Program
The program, developed by Jessica Fanning, a doctoral student at Oregon, trains parents to improve their communication skills and provides them with tools to improve their children's behavior, with the aim of reducing stress in the home. To test her program, Ms. Fanning recruited families from a Head Start program.
She found that after eight weekly sessions with parents, they reported less stress in the home, and their children performed significantly better on tests of language skills, nonverbal intelligence, memory, and attention.
The researchers have thus far tested only 14 low-income children and 14 controls. And they are tracking the children to see whether the effects persist. "At the end of the day, what we don't care about is a 5-point difference in I.Q.," said Ms. Stevens. "We care about this measure if it's going to translate into something persistent and useful."
While many of the researchers at the session supported the hypothesis that socioeconomic status plays a strong role in affecting brain development in children, Mabel L. Rice, director of the doctoral program in child language at the University of Kansas, described a new study that goes against the hypothesis, at least in the case of early verbal abilities. In tests of 1,766 children in Australia, Ms. Rice and her colleagues found no correlation between a child's verbal abilities at 24 months old and the parents' socioeconomic status or their education levels.
"The conclusion is that we don't want to assume too strongly that children of poverty are unable to acquire early vocabulary," she told The Chronicle.
Ms. Rice and three other researchers reported their results in December in the Journal of Speech, Language, and Hearing Research.
Monday, February 18, 2008
Researchers Gain Understanding of How Poverty Alters the Brain
By RICHARD MONASTERSKY
Brain studies of poor children reveal that their neural systems develop differently from those of other children, a finding that potentially points the way toward creating methods for ameliorating the effects of poverty on academic achievement.
"Growing up poor is bad for your brain—we've known that for a long time," said Martha J. Farah, director of the center for cognitive neuroscience at the University of Pennsylvania. "What's new is that neuroscientists have begun to try to understand this problem," she said last week at the annual meeting here of the American Association for the Advancement of Science, which ends today.
For generations, psychologists have noted that children raised in poverty perform poorer on cognitive tests, on average, than do students from wealthier families. Some researchers have taken those results to argue that intelligence is determined for the most part by genetics and that certain races are inherently smarter than others. In 1994, Richard J. Herrnstein and Charles Murray presented that case in their book, The Bell Curve: Intelligence and Class Structure in American Life.
But the new results from neuroscience indicate that experience, especially being raised in poverty, has a strong effect on the way the brain works. "It's not a case of bad genes," said Ms. Farah.
She and her colleagues have investigated the issue by trying to tease out which aspects of poverty alter specific cognitive skills, such as memory, language, and the ability to delay gratification. The researchers studied a group of African-American children of low socioeconomic status, who had been tracked from birth through high-school graduation by Hallam Hurt, a pediatrician at Penn.
Over the years, Dr. Hurt's team had assessed the home environments of the children, monitoring how nurturing parents were, and how intellectually stimulating the homes were—for example, whether the children had access to books and visited museums.
When Ms. Farah's team tested 110 of those children, they found that particular cognitive skills were linked with certain aspects of the environment. Children with better language abilities were more likely to come from intellectually stimulating homes, no matter how nurturing their parents were. Memory skills, however, matched the nurturing levels in the home, reported Ms. Farah, who will publish her results in an upcoming issue of Developmental Science.
Effect of Nurturing on the Brain
To test why, the researchers did MRI scans of the children. They found that students raised in nurturing homes generally had bigger hippocampi, the portion of the brain associated with forming and retrieving memories. The discovery dovetails with previous research in rodents, which showed that rats raised in a stressful environment develop smaller hippocampi.
The results of the new work suggest that "it's worth making intervention and prevention programs because clearly a lot of the action here is experiential," said Ms. Farah. "This points out the fact that these phenomena are the result of adverse environments."
At the science association's meeting, Courtney Stevens, a postdoctoral research associate at the University of Oregon's brain-development laboratory, described other experiments on the cognitive effects of poverty. In one study, researchers put a net of electrodes on the heads of children and measured their brain waves. The children were seated between two speakers playing different stories and they were asked to pay attention to only one of the stories.
While the stories were being read, the children heard identical bursts of distracting noise coming from either of the speakers. The brains of the children responded differently to those same noises, depending on whether it came from the side they were listening to or ignoring. It's almost as if the brain has a volume control, turning up the sound on the side it is attending to, said Ms. Stevens.
The study revealed that students from lower-income families were less able to screen out the noises embedded in the stories they were supposed to ignore.
The students in the higher-income group, however, "had more gain on their volume control," she said. "Their brains were able to make a larger distinction between what they were trying to hear versus ignore."
With those results and others suggesting that cognitive skills are strongly influenced by environment, the Oregon team is developing intervention programs to try to counteract the effects of poverty. At the meeting, Ms. Courtney described one experimental program that has shown initial success.
Parental-Intervention Program
The program, developed by Jessica Fanning, a doctoral student at Oregon, trains parents to improve their communication skills and provides them with tools to improve their children's behavior, with the aim of reducing stress in the home. To test her program, Ms. Fanning recruited families from a Head Start program.
She found that after eight weekly sessions with parents, they reported less stress in the home, and their children performed significantly better on tests of language skills, nonverbal intelligence, memory, and attention.
The researchers have thus far tested only 14 low-income children and 14 controls. And they are tracking the children to see whether the effects persist. "At the end of the day, what we don't care about is a 5-point difference in I.Q.," said Ms. Stevens. "We care about this measure if it's going to translate into something persistent and useful."
While many of the researchers at the session supported the hypothesis that socioeconomic status plays a strong role in affecting brain development in children, Mabel L. Rice, director of the doctoral program in child language at the University of Kansas, described a new study that goes against the hypothesis, at least in the case of early verbal abilities. In tests of 1,766 children in Australia, Ms. Rice and her colleagues found no correlation between a child's verbal abilities at 24 months old and the parents' socioeconomic status or their education levels.
"The conclusion is that we don't want to assume too strongly that children of poverty are unable to acquire early vocabulary," she told The Chronicle.
Ms. Rice and three other researchers reported their results in December in the Journal of Speech, Language, and Hearing Research.
Sunday, January 20, 2008
Monday, December 31, 2007
Thursday, August 30, 2007
Saturday, August 18, 2007
Wednesday, August 1, 2007
Saturday, July 21, 2007
Brain damage turns man into human chameleon
"In his 1983 fake documentary 'Zelig', Woody Allen plays a character, Leonard Zelig, a kind of human chameleon who takes on the appearance and behaviour of whoever he is with. Now psychologists in Italy have reported the real-life case of AD, a 65-year-old whose identity appears dependent on the environment he is in. He started behaving this way after cardiac arrest caused damage to the fronto-temporal region of his brain."
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