In today’s Academic Minute, Dr. James Cavanagh of Brown University reveals how our brain and behavior can be influenced by our evolutionary past.
James Cavanagh is a postdoctoral research associate at Brown University where he works in the Laboratory of Neural Computation and Cognition. The LNCC examines the role of genetics in predicting an individual’s ability to learn from rewards and punishments. During the summer of 2013, Cavanagh will establish a new research lab at the University of New Mexico where he will begin an assistant professorship.
Dr. James Cavanagh – The Impulse to Do Nothing
It can be hard to overcome our habits. For example, it is easy to motivate an action to obtain a reward, or to inhibit action to avoid punishment. Animals, including humans, have deeply ingrained biology to actively seek food and to freeze to avoid a predator. Scientists, meanwhile, have long known that it can be impossible to condition chickens and rats to accomplish the alternatives: act to avoid bad things, or withhold action to get a reward. Those animals don’t have the luxury of extensive prefrontal cortices to override their innate biases, like people do.
In recent study I completed with Michael Frank, we tested a potential mechanism by which the human prefrontal cortex contributes to better behavior. Participants played a video game where they saw different symbols indicating they had to learn to make or inhibit an action to either gain a reward or avoid a punishment. We also recorded EEG – brain electrical activity – while people performed this task. As ingrained biases would suggest, people were very good at learning to act to get reward and inhibit action to avoid punishment. Yet people were widely varied in their abilities to learn to act to avoid punishment or inhibit to get reward. We were able to predict these differences from the EEG activity that occurred when people looked at the symbol: people with more theta band power in the prefrontal cortex had a better ability to override their innate biases.
These findings provided clear evidence that frontal theta acts as an ‘alarm bell’ to warn of the upcoming motivational conflict between ingrained bias and the desired outcome. Now we’re expanding these findings by revealing what other brain systems responded to this ‘alarm’ to shape behavior, by applying this task with psychiatric patients to assess the integrity of prefrontal control, and even selectively modulating frontal theta to see if we can diminish or enhance this adaptive tendency in healthy individuals.
Production support for the Academic Minute comes from Newman’s Own, giving all profits to charity and pursuing the common good for over 30 years, and from Mount Holyoke College.