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May. 24th, 2004 03:09 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
novapsycheRegrets Are Few if Brain Is Damaged
Regret is a complex emotion that helps guide humans in regulating their individual and social behavior.
It is also vulnerable to injury to the brain, a new study says.
Research appearing in the May 21 issue of Science found that when the region of the brain known as the orbitofrontal cortex was damaged, people no longer experienced regret and couldn't anticipate the consequences of their actions when participating in a gambling exercise.
"If I can rehearse in my head how I will feel if I make the wrong choice, I'll be more careful if I have two alternatives," said study co-authors Angela Sirigu, director of research at The French National Center for Scientific Research in Bron. "In patients with orbitofrontal lesions, they don't care about what happens with alternatives. It looks like this region of the brain is very important for the experience of regret," she said.
For this study, Sirigu and her colleagues recruited five people with damage to their orbitofrontal cortex that occurred during a stroke and 18 people with no brain damage. The study volunteers were male and female and their average age was about 55.
They had all of the volunteers participate in gambling exercises. In each exercise, they were asked to choose one of two wheels. Each wheel contained an arrow that would spin and eventually stop on one of four conditions: +50, -50, +200 or -200 (at the time of the study, the unit of money used was French francs.) In one exercise, the arrow would only spin in the chosen wheel. In the other, both arrows would spin, allowing the study volunteers to see what the outcome would have been had they chosen the other wheel.
After each exercise, the volunteers were asked to rate how happy or sad they felt on a scale of -50 to +50, with +50 being extremely happy.
Not surprisingly, people without any damage to their brains weren't pleased when their decision cost them money. However, Sirigu said, knowing what happened on the other wheel could significantly alter how they felt. For example, if they won 50 francs but the other wheel won 200, they were sad, whereas if they had won 50 and not known the outcome of the other wheel, they would have been happy.
On the other hand, people with orbitofrontal lesions didn't care what happened on the alternative wheel, she said. These people also made no attempt to minimize their future losses, as the healthy people did.
"Regret is important for when we are making a choice to make the good choice," Sirigu said.
She noted people with damage to this area of the brain often behave very differently. She said they tend to make risky choices, don't care if they make the wrong choice, and have problems with social interactions.
In the future, Sirigu said, she is planning on studying the brains of people addicted to risk, such as compulsive gamblers, using scans to see what areas of the brain are activated by these behaviors.
"Orbitofrontal damage robs people of the ability to anticipate the consequences of their actions," said Dr. Elkhonon Goldberg, a neuropsychologist at New York University Medical Center and author of The Executive Brain: Frontal Lobes and The Civilized Mind.
He said this was an interesting study that confirmed the role of the orbitofrontal cortex in emotional control. He added the orbitofrontal cortex is not alone in processing complex emotions, such as regret, and said that if the authors had studied other parts of the prefrontal cortex they likely would have noted differences there as well.
---
How we dig up distant memories
Scientists have discovered how the brain can summon up our oldest memories from years past.
They have found that the process is controlled by an area called the anterior cingulate.
It is hoped that the breakthrough could lead to the development of new treatments for Alzheimers and other forms of dementia.
The work, by the University of California Los Angeles, is published in Science.
Scientists have long known that a structure called the hippocampus processes recent memories.
However, it was also known that the hippocampus did not store this information permanently.
And just how the brain is able to retrieve more distant recollections, often from many years ago, had been a mystery.
The UCLA team engineered mice with a mutant form of a gene called kinase II, which eliminates the ability to recall old memories.
The animals were trained to recognise a cage, then tested for their memory of the cage at one, three, 18 and 36 days after training.
The mutant mice recognized the cage for up to three days after training - but showed no signs of recognition when tested again at a later date.
Earlier research suggested that the cortex - or outer layer of the brain - plays a role in the storage and retrieval of old memories.
Next, the UCLA team tested this theory by using imaging methods to track activity in a normal mouse's cortex during memory testing.
No part of the cortex lit up when the animal was exposed to the cage one day after training. When the mouse saw the cage 36 days after training, however, the images highlighted a part of the cortex called the anterior cingulate.
In contrast, the mutant mice's anterior cingulate never switched on during tests for distant memory.
In the third part of their experiment, the researchers injected normal mice with a drug that temporarily turned off the anterior cingulate.
This did not disrupt the animals' memory of the cage at one and three days after training - but did at 18 and 36 days.
Lead researcher Professor Alcino Silva said: "We now had several pieces of evidence all pointing to the same conclusion - the anterior cingulate plays a special role in keeping our early memories alive.
"Our work with the mutant mice also suggests that kinase II is critically involved in preserving our oldest memories."
Professor Silva believes the anterior cingulate assembles signals of an old memory from different sites in the brain.
Dementia may result from a malfunction in this assembling process, leaving the memory too fragmented to make proper sense.
Harriet Millward, of the Alzheimer's Research Trust, told BBC News Online: "Both ageing and certain aspects of Alzheimer's disease and other dementias - such as agitation, depression, apathy, and loss of attention - are all accompanied by reduced activity in the anterior cingulate.
"This study is interesting in making such a clear distinction between short-term and long-term memory and associating the anterior cingulate specifically with the latter.
"However, this has only been shown in mice so far. If these findings can be supported by studies in humans, then they will make a useful contribution to our understanding of Alzheimer's disease and other dementias."
Regret is a complex emotion that helps guide humans in regulating their individual and social behavior.
It is also vulnerable to injury to the brain, a new study says.
Research appearing in the May 21 issue of Science found that when the region of the brain known as the orbitofrontal cortex was damaged, people no longer experienced regret and couldn't anticipate the consequences of their actions when participating in a gambling exercise.
"If I can rehearse in my head how I will feel if I make the wrong choice, I'll be more careful if I have two alternatives," said study co-authors Angela Sirigu, director of research at The French National Center for Scientific Research in Bron. "In patients with orbitofrontal lesions, they don't care about what happens with alternatives. It looks like this region of the brain is very important for the experience of regret," she said.
For this study, Sirigu and her colleagues recruited five people with damage to their orbitofrontal cortex that occurred during a stroke and 18 people with no brain damage. The study volunteers were male and female and their average age was about 55.
They had all of the volunteers participate in gambling exercises. In each exercise, they were asked to choose one of two wheels. Each wheel contained an arrow that would spin and eventually stop on one of four conditions: +50, -50, +200 or -200 (at the time of the study, the unit of money used was French francs.) In one exercise, the arrow would only spin in the chosen wheel. In the other, both arrows would spin, allowing the study volunteers to see what the outcome would have been had they chosen the other wheel.
After each exercise, the volunteers were asked to rate how happy or sad they felt on a scale of -50 to +50, with +50 being extremely happy.
Not surprisingly, people without any damage to their brains weren't pleased when their decision cost them money. However, Sirigu said, knowing what happened on the other wheel could significantly alter how they felt. For example, if they won 50 francs but the other wheel won 200, they were sad, whereas if they had won 50 and not known the outcome of the other wheel, they would have been happy.
On the other hand, people with orbitofrontal lesions didn't care what happened on the alternative wheel, she said. These people also made no attempt to minimize their future losses, as the healthy people did.
"Regret is important for when we are making a choice to make the good choice," Sirigu said.
She noted people with damage to this area of the brain often behave very differently. She said they tend to make risky choices, don't care if they make the wrong choice, and have problems with social interactions.
In the future, Sirigu said, she is planning on studying the brains of people addicted to risk, such as compulsive gamblers, using scans to see what areas of the brain are activated by these behaviors.
"Orbitofrontal damage robs people of the ability to anticipate the consequences of their actions," said Dr. Elkhonon Goldberg, a neuropsychologist at New York University Medical Center and author of The Executive Brain: Frontal Lobes and The Civilized Mind.
He said this was an interesting study that confirmed the role of the orbitofrontal cortex in emotional control. He added the orbitofrontal cortex is not alone in processing complex emotions, such as regret, and said that if the authors had studied other parts of the prefrontal cortex they likely would have noted differences there as well.
---
How we dig up distant memories
Scientists have discovered how the brain can summon up our oldest memories from years past.
They have found that the process is controlled by an area called the anterior cingulate.
It is hoped that the breakthrough could lead to the development of new treatments for Alzheimers and other forms of dementia.
The work, by the University of California Los Angeles, is published in Science.
Scientists have long known that a structure called the hippocampus processes recent memories.
However, it was also known that the hippocampus did not store this information permanently.
And just how the brain is able to retrieve more distant recollections, often from many years ago, had been a mystery.
The UCLA team engineered mice with a mutant form of a gene called kinase II, which eliminates the ability to recall old memories.
The animals were trained to recognise a cage, then tested for their memory of the cage at one, three, 18 and 36 days after training.
The mutant mice recognized the cage for up to three days after training - but showed no signs of recognition when tested again at a later date.
Earlier research suggested that the cortex - or outer layer of the brain - plays a role in the storage and retrieval of old memories.
Next, the UCLA team tested this theory by using imaging methods to track activity in a normal mouse's cortex during memory testing.
No part of the cortex lit up when the animal was exposed to the cage one day after training. When the mouse saw the cage 36 days after training, however, the images highlighted a part of the cortex called the anterior cingulate.
In contrast, the mutant mice's anterior cingulate never switched on during tests for distant memory.
In the third part of their experiment, the researchers injected normal mice with a drug that temporarily turned off the anterior cingulate.
This did not disrupt the animals' memory of the cage at one and three days after training - but did at 18 and 36 days.
Lead researcher Professor Alcino Silva said: "We now had several pieces of evidence all pointing to the same conclusion - the anterior cingulate plays a special role in keeping our early memories alive.
"Our work with the mutant mice also suggests that kinase II is critically involved in preserving our oldest memories."
Professor Silva believes the anterior cingulate assembles signals of an old memory from different sites in the brain.
Dementia may result from a malfunction in this assembling process, leaving the memory too fragmented to make proper sense.
Harriet Millward, of the Alzheimer's Research Trust, told BBC News Online: "Both ageing and certain aspects of Alzheimer's disease and other dementias - such as agitation, depression, apathy, and loss of attention - are all accompanied by reduced activity in the anterior cingulate.
"This study is interesting in making such a clear distinction between short-term and long-term memory and associating the anterior cingulate specifically with the latter.
"However, this has only been shown in mice so far. If these findings can be supported by studies in humans, then they will make a useful contribution to our understanding of Alzheimer's disease and other dementias."
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(no subject)
Date: 2004-05-24 01:10 pm (UTC)I wonder if age affects our Orbitofrontal regions?