Motivated attention: incentive effects on attentional modification of prepulse inhibition.

Prepulse inhibition (PPI) of startle is greater for attended compared to ignored prestimuli, and, consistent with theories of motivated attention, initial evidence suggests that this effect is greater among participants given performance-based incentives. The present study examined a within-subjects incentive manipulation. Participants (n=41) completed two blocks of a tone discrimination task. During the incentive block, participants received trialwise feedback with small monetary incentives for task performance. Startle eyeblink EMG responses to auditory probes were assessed at 60-, 120-, and 180-ms tone-probe stimulus onset asynchronies (SOAs). As predicted, PPI was enhanced during attended compared to ignored prestimuli only at the 120-ms SOA in the incentive condition. There was no evidence of attentional modification in the no-incentive condition. These data suggest that attentional modification of PPI is sensitive to within-subjects manipulations of incentive, providing a useful tool for testing models of motivated attention in psychopathology and psychopharmacology.