RT Journal Article SR Electronic T1 Strategic and Dynamic Temporal Weighting for Perceptual Decisions in Humans and Macaques JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0169-18.2018 DO 10.1523/ENEURO.0169-18.2018 VO 5 IS 5 A1 Aaron J Levi A1 Jacob L. Yates A1 Alexander C. Huk A1 Leor N. Katz YR 2018 UL http://www.eneuro.org/content/5/5/ENEURO.0169-18.2018.abstract AB Perceptual decision-making is often modeled as the accumulation of sensory evidence over time. Recent studies using psychophysical reverse correlation have shown that even though the sensory evidence is stationary over time, subjects may exhibit a time-varying weighting strategy, weighting some stimulus epochs more heavily than others. While previous work has explained time-varying weighting as a consequence of static decision mechanisms (e.g., decision bound or leak), here we show that time-varying weighting can reflect strategic adaptation to stimulus statistics, and thus can readily take a number of forms. We characterized the temporal weighting strategies of humans and macaques performing a motion discrimination task in which the amount of information carried by the motion stimulus was manipulated over time. Both species could adapt their temporal weighting strategy to match the time-varying statistics of the sensory stimulus. When early stimulus epochs had higher mean motion strength than late, subjects adopted a pronounced early weighting strategy, where early information was weighted more heavily in guiding perceptual decisions. When the mean motion strength was greater in later stimulus epochs, in contrast, subjects shifted to a marked late weighting strategy. These results demonstrate that perceptual decisions involve a temporally flexible weighting process in both humans and monkeys, and introduce a paradigm with which to manipulate sensory weighting in decision-making tasks.