RT Journal Article SR Electronic T1 Distinct behavioral effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat JF bioRxiv FD Cold Spring Harbor Laboratory SP 011031 DO 10.1101/011031 A1 Jeffrey C. Erlich A1 Bingni W. Brunton A1 Chunyu A. Duan A1 Timothy D. Hanks A1 Carlos D. Brody YR 2014 UL http://biorxiv.org/content/early/2014/11/04/011031.abstract AB Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evidence have yet to be determined. Here, in rats performing a sensory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best described as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating evidence, even while finding a strong role for PPC in internally-guided decisions.