Jay and Juan building on Feng and Holmes Dynamics of reward bias effects in a difficult perceptual identification task Jay and Juan building on Feng and Holmes

Integration of reward and motion information in percpetual decision making (Rorie & Newsome) Monkey’s choices reflect a beautifully regular combination of the effects of stimulus coherence and reward.

Population response of LIP Neurons in two reward conditions Choose in Choose out

Human Experiment Manipulating Stimulus Response Interval using the Response Signal Method Stimuli are rectangles shifted 1,3, or 5 pixels L or R of fixation Reward cue occurs 750 msec before stimulus. Small arrow head vis for 250 msec. Only 2-1 and 1-2 conditions are considered. Response signal occurs at these times after stimulus onset: 0 75 150 225 300 450 600 900 1200 2000 Participant receives 1 or 2 point reward if response occurs within 250 msec of response signal and is correct. Participants were run for 15-25 sessions to provide stable data. Data shown are from later sets of sessions in which the biasing effect of reward appeared to be fairly stable. Three participants have been run for shorter time with same arrows but equal reward to demonstrate that effects of reward bias are not due to arrows per se.

Data Slides Equal reward data showing absence of bias effect for arrows without reward differences Bias early and late in stimulus interval by sessions Full data for stable sessions for the five participants receiving differential rewards

Bias for three participants with arrows but no differential reward

CM JA MJ SL ZA P(choose lg rwd) Early Late Dark = rwd cong stimuli Light = rwd incng stimuli Sessions right of line included in later graphs SL ZA