Laboratory

in sensory physiology

Effective perceptual decisions rely upon combining sensory information with knowledge of the rewards available for different choices. Postdoctoral researcher Nela Cicmil combined electrical microstimulation of functionally specific groups of neurons in visual area V5/MT with performance-contingent reward manipulation, while monkeys performed a visual discrimination task. Microstimulation was less effective in shifting perceptual choices towards the stimulus preferences of the stimulated neurons when available reward was larger. Psychophysical control experiments showed this result was not explained by a selective change in response strategy on microstimulated trials. A bounded accumulation decision model, applied to analyse behavioural performance, revealed that the interaction of expected reward with microstimulation can be explained if expected reward modulates a sensory representation stage of perceptual decision-making. Cicimil et al 2015 eLife; Cicmil & Krug 2015 Phil Trans B.