Decreased neuronal activity in reward circuitry of pathological gamblers during processing of personal relevant stimuli.

Pathological gamblers impress by an increasing preoccupation with gambling, which leads to the neglect of stimuli, interests, and behaviors that were once of high personal relevance. Neurobiologically dysfunctions in reward circuitry underlay pathological gambling. To explore the association of both findings, we investigated 16 unmedicated pathological gamblers using an fMRI paradigm that included two different tasks: the evaluation of personal relevance and a reward task that served as a functional localizer. Pathological gamblers revealed diminished deactivation during monetary loss events in some of our core reward regions, the left nucleus accumbens and the left putamen. Moreover, while pathological gamblers viewed stimuli of high personal relevance, we found decreased neuronal activity in all of our core reward regions, including the bilateral nucleus accumbens and the left ventral putamen cortex as compared to healthy controls. We demonstrated for the first time altered neuronal activity in reward circuitry during personal relevance in pathological gamblers. Our findings may provide new insights into the neurobiological basis of pathological gamblers' preoccupation by gambling.

Is our self nothing but reward? Neuronal overlap and distinction between reward and personal relevance and its relation to human personality.

BACKGROUND: The attribution of personal relevance, i.e. relating internal and external stimuli to establish a sense of belonging, is a common phenomenon in daily life. Although previous research demonstrated a relationship between reward and personal relevance, their exact neuronal relationship including the impact of personality traits remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Using functional magnetic resonance imaging, we applied an experimental paradigm that allowed us to explore the neural response evoked by reward and the attribution of personal relevance separately. We observed different brain regions previously reported to be active during reward and personal relevance, including the bilateral caudate nucleus and the pregenual anterior cingulate cortex (PACC). Additional analysis revealed activations in the right and left insula specific for the attribution of personal relevance. Furthermore, our results demonstrate a negative correlation between signal changes in both the PACC and the left anterior insula during the attribution of low personal relevance and the personality dimension novelty seeking. CONCLUSION/SIGNIFICANCE: While a set of subcortical and cortical regions including the PACC is commonly involved in reward and personal relevance, other regions like the bilateral anterior insula were recruited specifically during personal relevance. Based on our correlation between novelty seeking and signal changes in both regions during personal relevance, we assume that the neuronal response to personally relevant stimuli is dependent on the personality trait novelty seeking.