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Researchers at the Center for Neural Science and Medicine and the Cedars-Sinai Department of Neurosurgery have discovered how signals from a group of neurons in the frontal lobe of the brain simultaneously give humans the flexibility to learn new tasks and focus on developing highly skilled skills. specific.
His research, published today in the peer-reviewed journal science, provides a fundamental understanding of performance tracking, an executive function that is used to manage daily life.
The key finding of the study is that the brain uses the same group of neurons for performance feedback in many different situations, whether a person is trying a new task for the first time or working to hone a specific skill.
“Part of the magic of the human brain is that it’s so flexible,” said Ueli Rutishauser, Ph.D., a professor of Neurosurgery, Neurology and Biomedical Sciences, director of the Board of Governors’ Center for Neural Science and Medicine. Chair of Neuroscience and lead author of the study. “We designed our study to decipher how the brain can be generalized i specializing at the same time, both of which are key to helping us pursue a goal. ”
Performance tracking is an internal signal, a kind of self-generated feedback, that lets a person know they’ve made a mistake. An example is the person who notices that he passed an intersection where he should have turned. Another example is the person who says something in a conversation and recognizes as soon as the words come out of his mouth that what he has just said is inappropriate.
“That moment ‘Oh, shoot’, that ‘Ui!’ At the moment, performance monitoring is underway, “said Zhongzheng Fu, Ph.D., a postdoctoral researcher at the Cedars-Sinai Rutishauser Laboratory and lead author of the study.
These signals help to improve performance in future attempts by passing information to areas of the brain that regulate emotions, memory, planning, and problem solving. Performance tracking also helps the brain adjust its focus by indicating how many conflicts or difficulties were encountered during the task.
“So a ‘Oops!’ The moment can make someone pay more attention the next time they chat with a friend or plan to stop at the store back home from work, “Fu said.
To monitor performance in action, researchers recorded the activity of individual neurons in the medial frontal cortex of study participants. Participants were patients with epilepsy who, as part of their treatment, had electrodes implanted in their brain to help locate the focus of their seizures. Specifically, these patients had electrodes implanted in the medial frontal cortex, a brain region that is known to play a central role in performance control.
In Stroop’s task, which confronts reading with color naming, participants saw the written name of a color, such as “red,” printed in a different color ink, such as green, and He asked them to name the color of the ink instead of the written word.
“This creates conflicts in the brain,” Rutishauser said. “You have decades of training in reading, but now your goal is to suppress that habit of reading and say the color of the ink in which the word is written.”
In the other task, the multi-source interference task (MSIT), which involves number recognition, participants saw three numeric digits on the screen, two equal and the other single, for example, 1-2-2 . The subject’s task was to press the button associated with the unique number — in this case, “1” —resisting his tendency to press “2” because that number appears twice.
“These two tasks serve as solid evidence of how self-control is performed in different scenarios involving different cognitive domains,” Fu said.
A structured answer
While the subjects were performing these tasks, the researchers observed two different types of functioning neurons. “Error” neurons fired strongly after making a mistake, while “conflict” neurons fired in response to the difficulty of the task the subject had just performed.
“When we looked at the activity of neurons in this area of the brain, we were surprised that most of them were only activated after a decision or action was completed. This indicates that this area of the brain plays a role in the brain. ‘time to evaluate decisions after the fact, instead of making them.’
There are two types of performance control: general domain and specific domain. Tracking the overall performance of the domain tells us something failed and can detect errors on any type of task, whether someone is driving a car, browsing a social situation, or playing Wordle for the first time. This allows them to perform new tasks with little instruction, which machines cannot do.
“Machines can be trained to do something really good,” Fu said. “You can build a robot to turn burgers around, but you can’t adapt those skills to fry dough balls. Humans, by controlling the overall performance of the domain, can.”
Tracking domain-specific performance informs the person who made the mistake what has been mistaken, detecting specific errors: missing a turn, saying something inappropriate, or choosing the wrong letter in a puzzle. This is one way that people perfect their individual skills.
Surprisingly, neurons signaling general domain and domain-specific information were mixed into the medial frontal cortex.
“We used to think that there were parts of the brain dedicated only to controlling the overall performance of the domain and others only to a specific domain,” Rutishauser said.
“Our study now shows that this is not the case. We have learned that the same group of neurons can track the overall and specific performance of the domain. When you listen to these neurons, you can read both types of information simultaneously.”
To understand how these signals are interpreted by other areas of the brain, it helps to think of neurons as musicians in an orchestra, Rutishauser said.
“If everyone plays at random, the listeners, in this case, the regions of the brain that receive the signals, only hear a set of confusing notes,” Rutishauser said.
“But if they play an arranged composition, it’s possible to clearly hear the various melodies and harmonies even with so many instruments or neurons monitoring the performance playing at once.”
However, too much or too little of this signage can cause problems, Rutishauser said.
Hyperactive performance monitoring can be manifested as an obsessive-compulsive disorder, which causes a person to obsessively check for errors that do not exist. At the other end of the spectrum is schizophrenia, where performance monitoring can be inactive to the point that a person does not perceive mistakes or the inadequacy of their words or actions.
“We believe that the mechanistic knowledge we have acquired will be critical to perfecting treatments for these devastating psychiatric disorders,” Rutishauser said.
The research team also included Jeffrey Chung, MD, director of the Cedars-Sinai Epilepsy Program; Assistant Professor of Neurology Chrystal Reed, MD, Ph.D .; Adam Mamelak, MD, Professor of Neurosurgery and Director of the Functional Neurosurgery Program; Ralph Adolphs, Ph.D., Professor of Psychology, Neuroscience, and Biology at the California Institute of Technology; and associate researcher Danielle Beam.
About this neuroscience research news
Author: Press Office
Source: Cedars Sinai
Contact: Press Office – Cedars Sinai
Image: The image is in the public domain
Original research: Closed access.
“The geometry of overall domain performance control in the human medial frontal cortex” by Zhongzheng Fu et al. Science
The geometry of overall domain performance control in the human medial frontal cortex
Controlling behavior to flexibly achieve desired goals depends on the ability to control one’s own performance. It is unknown how performance monitoring can be both flexible, to support different tasks, and specialized, to perform each task well.
We recorded individual neurons in the human medial frontal cortex while subjects performed two tasks involving three types of cognitive conflict. Neurons encoding the probability of conflict, conflict, and error in one or both tasks were mixed, forming a representational geometry that simultaneously allowed for task specialization and generalization. The neurons encoding the conflict served retrospectively to update internal estimates of the likelihood of the conflict. Representations of the conflict population were compositional.
These findings reveal how representations of assessment signals can be both abstract and task-specific and suggest a neural mechanism for estimating control demand.