A UA professor and a team of researchers have used DNA from 69 college students to look for three specific genes that control dopamine in the brain, in an effort to form conclusions on learning.
Michael Frank, assistant professor of psychology and director of the UA’s Laboratory for Neural Computation and Cognition, led the research team.
Dopamine
The goal is to replicate and extend his work, which will help predict the way people learn.
-Jim Cavanagh,
cognition and neural systems graduate student
is a chemical in the brain that is often linked to memory, learning and motor skill – “”It’s critical for all of those functions,”” Frank said.
Poor regulation of dopamine in the brain has been linked to Parkinson’s disease, as well as addiction and schizophrenia. Medication for these afflictions often comes in the form of dopamine regulators, Frank said.
The research revolved around the effect of positive or negative reinforcement on people, leading to a theoretical model of how the three genes impact dopamine in the brain.
Research showed that two of the genes affect decisions made based on the outcome of many previous decisions, while the third is linked to the way a person’s choice changed after only one exposure to negative reinforcement.
To correlate the DNA findings to the subjects, the subjects used a computer program to test how well they learned from positive or negative feedback.
They were asked to pick between two Japanese symbols that were arbitrarily assigned as correct or incorrect. The subjects learned only by the positive or negative feedback they received, as they were rewarded or punished to prompt their subsequent decisions, Frank said.
Even though the subjects felt frustrated by the test, the data showed they learned from the feedback, Frank said.
“”This is the first time a genetic basis has been found for learning this way,”” he said.
Research indicated that some people naturally learn better from positive reinforcement and some from negative reinforcement. There are also people who respond well to both types, and those incapable of learning from either, Frank said.
There is still a lot of work to be done, but the research so far is promising, he added.
“”It’s potentially scary but also potentially very useful,”” he said.
As more is understood about the regulation of dopamine in the brain, it could be possible to genetically test people for their best learning style and treat them appropriately, Frank said.
The next experiment will be to test the importance of varying values of reward and punishment to learning according to reinforcement, he said.
Other researchers in the UA’s psychophysiology lab have “”replicated (Frank’s) findings and extended them,”” said Jim Cavanagh, a third-year cognition and neural systems
graduate student.
Cavanagh’s work with his advisor, psychology professor John Allen, uses Frank’s model and some of his findings for tests on clinical groups that include people with obsessive-compulsive disorder and major depressive disorder, Cavanagh said.
The research involves electroencephalography, which measures the brain’s electrical activity through the attachment of electrodes to the scalp.
“”The goal is to replicate and extend (Frank’s) work,”” which will help predict the way people learn, Cavanagh said, adding that he and other researchers will present their work for the Society of Psychophysiological Research in two weeks.
