Monday, June 30, 2008

Using Mental Strategies Can Alter the Brain's Reward Circuitry

From New York University news release:Using Mental Strategies Can Alter The Brain's Reward Circuitry

The cognitive strategies humans use to regulate emotions can determineboth neurological and physiological responses to potential rewards, ateam of New York University and Rutgers University neuroscientists hasdiscovered. The findings, reported in the most recent issue of thejournal Nature Neuroscience, shed light on how the regulation ofemotions may influence decision making.Previous research has demonstrated these strategies can alter responsesto negative events. However, less understood is whether such strategiescan also efficiently regulate expectations of a future reward or adesired outcome.

Scientists have already determined that the expectationof a potential reward brings about positive feelings and aidsrecognizing environmental cues that predict future rewards. Central tothis process is the role of the striatum, a multi-faceted structure inthe brain that is involved in reward processing--and which is especiallyengaged when potential rewards are predicted or anticipated.However, the striatum signal is not always beneficial. Its activity also correlates with drug-specific cravings, most likely increasing urges to partake in risk-seeking behavior in the pursuit of rewards that aredetrimental. Therefore, understanding how to regulate or control thepositive feelings associated with reward expectation is an importantline of inquiry.

The NYU study was conducted by a team of researchers from the laboratoryof NYU Professor Elizabeth Phelps, who co-authored the work withMauricio R. Delgado, now a professor at Rutgers University, and M.Meredith Gillis, an NYU graduate student. They sought to betterunderstand the influence of emotional regulation strategies on thephysiological and neural processes relevant to expectations of reward.The study's subjects were presented with two conditioned stimuli, a blueand a yellow square that either predicted or did not predict a potentialmonetary reward. Prior to each trial, participants were also given awritten cue that instructed them to either respond to the stimulus("think of the meaning of the blue square, such as a potential reward")or regulate their emotional response to the stimulus ("think ofsomething blue in nature that calms you down, such as the ocean").Skin conductance responses (SCRs) of the participants were taken at thebeginning of each conditioned stimulus. These served as a behavioralmeasure of physiological reaction potentially related to reward anticipation.

The results showed that the participants' emotion regulation strategiescould influence physiological and neural responses relevant to theexpectation of reward. Specifically, results from the SCRs revealed thatthe subjects' emotion regulation strategies decreased arousal that waslinked to the anticipation of a potential reward."Our findings demonstrated that emotion regulation strategies cansuccessfully curb physiological and neural responses associated with theexpectation of reward," said Delgado. "This is a first step tounderstanding how our thoughts may effectively control positive emotionsand eventual urges that may arise, such as drug cravings."The work was supported by the James S. McDonnell Foundation, theBeatrice and Samuel A. Seaver Foundation, and the National Institute onDrug Abuse.

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