The influence of motivational salience within the dopamine-striatal system: a DCM study

Wednesday, October 26, 2011 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center	NIMH	NEURO/BEHAV/SENSYS-3

Authors

• DN Blitzer
• SA Colalillo
• MR Haynes
• JW Barter
• DR Weinberger
• CF Zink

Abstract

Areas within the dopamine-striatal system have been shown to respond to stimuli predicting motivationally salient events. Neuroimaging studies have corroborated these findings; however, little is known about how motivationally salient information modulates connections in this system. The current study investigated how different levels of motivationally salient stimuli influence coupling between the midbrain and ventral striatum (vStr) using Dynamic Causal Modeling (DCM) of fMRI data. Participants performed a modified version of the Monetary Incentive Delay task in which cues with varying salience were presented immediately prior to the target. One cue predicted a short response window (high motivational salience), and the other predicted a long response window (low motivational salience). The data were analyzed using DCM, an analysis method that assesses the effective connectivity between regions and the modulatory influence of external stimuli on intrinsic connections. In line with previous studies, we found that only behaviorally relevant cues displayed a significant modulation of midbrain to striatal connectivity. Importantly, this modulation was significantly greater for the more motivationally salient cue. Our results indicate that while the same regions respond to behaviorally relevant stimuli, the extent to which the midbrain drives the vStr is associated with the motivational salience assigned to a stimulus.

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