Friday, December 12, 2008

The Dana Foundation - The Prefrontal Cortex and Frontal Lobe Disorders : An Interview with Jordan Grafman, Ph.D.

The Dana Foundation - The Prefrontal Cortex and Frontal Lobe Disorders : An Interview with Jordan Grafman, Ph.D.

My research indicates that the human prefrontal cortex is especially designed to store in long-term memory the features that are unique to large structured sets of sequential events such as themes, morals, and plans. This enables us to put off immediate gratification, and allows us to out-think faster and stronger competitors. These observations form the foundation for the notion that the human prefrontal cortex is a crowning achievement of the human brain and that, like the rest of the brain, is a work in progress.

Q: You consider the prefrontal cortex to be the seat of “social cognition” and possibly “moral cognition” as well. What do these terms mean and what leads you to these conclusions?

A: Social cognition refers to the long-term memories we access when we interact socially with others, and that guide our social behaviors in routine and novel situations. These long-term memories contain information about how we accomplished social goals—from obtaining permission to do something, to taking leadership, to collaborating on a project —and incorporate information about perception and action. Moral cognition is a specific example of social cognition that pertains to ethical, legal, and “folk” justice, beliefs, and rules.

My colleagues and I (and others) have argued that the pre­frontal cortex is uniquely suited to manage social and moral cognition because it aids us in controlling our immediate reactions to a stimulus (like a face or gesture) and is critical for forecasting the consequences of a current behavior on a long-term goal. While other species have social cognitive abili­ties and some rudimentary features of moral cognition, social cognitive abilities reach their peak in humans (as does the anatomy and physiology of the prefrontal cortex). Like the prefrontal cortex, social cognition only matures in the second decade of life and shows some decline in old age.

In addition, brain damage in the prefrontal cortex due to head injuries, strokes, and dementing illnesses (among other brain disorders) often result in altered social cognitive abilities. Patients with lesions in the prefrontal cortex may behave inap­propriately in public, violating social rules such as personal space maintenance, social contracts, or inappropriate verbal­izations. The earliest example of this comes from the famous brain-injured patient Phineas Gage, but many modern-day Gages have been reported in great detail, highlighting the unfortunate case histories of these patients.

No comments: