summary: The neurotransmitter dopamine plays a key role in encoding prediction errors for both reward and punishment in the human brain.
This study suggests that dopamine is essential for learning from both positive and negative experiences, allowing the brain to adapt behavior based on the outcome. Scientists used electrochemical techniques and machine learning to measure dopamine levels in real time during computer games with rewards and penalties.
The findings reveal the complex role of dopamine in human behavior and may have implications for our understanding of psychiatric and neurological disorders.
Important facts:
- Dopamine functions as a neurotransmitter in the brain, facilitating communication between nerve cells and playing a role in movement, cognition, and learning.
- This study is the first to investigate how dopamine encodes rewards and punishments on fast timescales in the human brain.
- Understanding the role of dopamine in both rewarding and punishing experiences may provide insight into mental and neurological disorders.
sauce: Wake Forest Baptist Medical Center
What happens in the human brain when we learn from positive and negative experiences? To answer that question and better understand decision-making and human behavior, scientists study dopamine. I am.
Dopamine is a neurotransmitter produced in the brain that acts as a chemical messenger, facilitating communication between nerve cells in the brain and body. It is involved in functions such as movement, cognition, and learning. Although dopamine is best known for its association with positive emotions, scientists are also studying its role in negative experiences.
Now, a new study by researchers at Wake Forest University School of Medicine was published on December 1st. scientific progress Dopamine release in the human brain has been shown to play an important role in encoding prediction errors for both rewards and punishments.
This means that dopamine is involved in the process of learning from both positive and negative experiences, allowing the brain to adjust and adapt behavior based on the results of these experiences.
“Previous research has shown that dopamine plays an important role in how animals learn from ‘rewarding’ (and sometimes ‘punishing’) experiences. However, little research has been done to directly assess how dopamine acts in the human brain on fast timescales,” said Kenneth, associate professor of physiology, pharmacology, and neurosurgery at Wake Forest University School of Medicine. Dr. T. Kishida said.
“This is a human-based study that examines how dopamine encodes reward and punishment, and whether dopamine reflects the ‘optimal’ educational signals used in today’s cutting-edge artificial intelligence research. This is the first study to
In this study, researchers from Kishida’s team utilized fast-scan cyclic voltammetry, an electrochemical technique combined with machine learning, to detect and measure dopamine levels in real time (i.e., measurements). However, this method is difficult and can only be performed for invasive procedures such as deep brain stimulation (DBS) brain surgery.
DBS is commonly used to treat conditions such as Parkinson’s disease, essential tremor, obsessive-compulsive disorder, and epilepsy.
Professor Kishida’s team collaborated with Atrium Health Wake Forest Baptist neurosurgeons Steven B. Tutter, MD, and Adrian W. Ruxton, MD, both faculty members in the Department of Neurosurgery at Wake Forest University School of Medicine. Also, a carbon fiber microelectrode was inserted. Deep inside the brains of three participants scheduled to undergo DBS to treat essential tremor at Atrium Health Wake Forest Baptist Medical Center.
Participants played a simple computer game while awake in the operating room. While they played the game, dopamine measurements were taken in the striatum, a part of the brain important for cognition, decision-making, and coordination.
During the game, participants’ choices are rewarded or punished with real monetary gains or losses. The game was divided into three stages in which participants learned from positive or negative feedback and made choices that maximized rewards and minimized penalties. Throughout each of his three stages of the game, dopamine levels were continuously measured every 100 milliseconds.
“We know that dopamine not only plays a role in signaling both positive and negative experiences in the brain, but also appears to do so in an optimal way when trying to learn from those consequences. What’s also interesting is that there may be independent pathways in the brain that engage the dopamine system differently for rewarding and punishing experiences.
“Our findings suggest that these two pathways may encode rewarding and punishing experiences on slightly offset timescales, with a time difference of only 200 to 400 milliseconds.” We revealed surprising results,” said Kishida.
Professor Kishida believes this level of understanding could lead to a better understanding of how the dopamine system is affected in people with mental and neurological disorders. Professor Kishida said additional research is needed to understand how dopamine signaling changes in psychiatric and neurological diseases.
“Traditionally, dopamine is often referred to as the ‘pleasure neurotransmitter,'” says Kishida.
“However, our study provides evidence that this is not the way we think about dopamine. Rather, dopamine is an important part of a sophisticated system that teaches our brains and guides our behavior.
“The implication that dopamine is involved in teaching our brains to experience punitive experiences is an important discovery that may explain the mechanisms underlying depression, addiction, and related mental and neurological disorders. It has the potential to provide new directions for research that will help us understand it more deeply.”
About this dopamine and learning research news
author: Kenneth T. Kishida
sauce: Wake Forest Baptist Medical Center
contact: Kenneth T. Kishida – Wake Forest Baptist Medical Center
image: Image credited to Neuroscience News
Original research: Open access.
“Subsecond fluctuations in extracellular dopamine encode prediction errors of reward and punishment in humansWritten by Paul Sands et al. scientific progress
abstract
Subsecond fluctuations in extracellular dopamine encode prediction errors of reward and punishment in humans
In the mammalian brain, activity in dopamine neurons in the midbrain is hypothesized to facilitate learning by triggering rapid changes in dopamine levels in target brain regions, encoding reward prediction errors that guide behavior. I am.
This hypothesis (and alternatives regarding the role of dopamine in punishment learning) has limited direct evidence in humans. We performed a probabilistic reward and punishment learning choice task on volunteers (i.e., deep brain stimulation surgery) designed to test whether dopamine release encodes only reward prediction errors or whether dopamine release encodes We report that we have measured intracranial subsecond measurements of dopamine release in the human striatum during a run (patients who received the test). It is also possible to encode adaptive punishment learning signals.
Results show that extracellular dopamine levels can encode prediction errors for both reward and punishment within different time intervals through independent valence-specific pathways in the human brain.