- Tel: (443) 722-6746
- Email: geoffrey.
A key feature of behavior - adaptive behavior - is that it takes into account consequences. In other words, when you decide to take an action, you - ie your brain - embarks on that course of action because of a desire to obtain or avoid some outcome. Even more importantly you - ie your brain - use information you have learned about relationships or associations between cues in the environment and likely outcomes of your actions. These associative representations - instantiated in the architecture and electrical activity of your brain - modulate and modify your actions in both large and small ways. Indeed you can feel their operation in considering the two pictures below; these reactions reflect the incentive value of the outcomes you have learned to associate with these cues.
You use incentive value of the outcome both overtly and covertly to guide your responses to cues and circumstances such as these.
Without this ability you might engage in habit-driven and inappropriate behavior.
Perhaps the most famous example of this deficit occurred in a patient named Phineas Gage. Gage was a railroad worker in the mid-1800's, who suffered a terrible accident in which a 3 ft metal rod was blasted through the front of his brain. He recovered from this accident, but despite mostly intact neurological function was never able to recover his 'self'.
After his recovery, in an 1868 report, his physician John Harlow described him as:
“...fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operation which are no sooner arranged than they are abandoned” - Harlow, 1868
Gage had become unable to control his behavior according to the consequences or outcomes of his actions.
Humans are perhaps (but not necessarily) unique in our ability to create abstractions upon abstractions of outcomes to guide our behavior, but the general principles and indeed circuits governing this ability appear to be largely conserved in many mammalian species. From humans, to non-human primates, to rats, the evidence indicates that the ability to form and use information about outcomes depends critically upon processing in a circuit of brain regions including the orbitofrontal cortex (OFC), basolateral amygdala (ABL), and nucleus accumbens (NA).
By studying how these brain areas mediate goal-directed behavior in rats, we can understand how the same circuit functions in humans. More importantly, we can also use our model to study how the normal function of this circuit is disrupted in clinical brain disorders and how treatments might address this disruption.
These are the long-term research goals of the lab - first to employ a multidisciplinary approach to characterize the respective functions of the system of structures centered on the orbitofrontal cortex in normal rats, and second to use this basic research as a springboard to explore the basis of disorders, such as addiction and age-related cognitive decline, that impact this system.