Fig. 1

Task procedure and marginal bias plots. A Sequence of events in a trial. On each trial, subjects viewed a random-dot motion stimulus and reported the perceived direction of motion by extending a dark bar from the center point. They were instructed to report the direction of motion of dots by swiping their finger on a touchpad to extend a bar from the center of the display to the direction of their estimate and confirm that report with a click on the touchpad. B Bias plot marginalized on the relative direction of the previous stimulus. Response errors are expressed as a function of the relative direction of the previous stimulus (i.e., previous stimulus minus current stimulus). Consistent with earlier studies, estimation responses are systematically biased to the previous stimulus. C Bias plot marginalized on the relative direction of the previous response. Response errors are expressed as a function of the relative direction of the previous response (i.e., previous response minus current stimulus). For each subject, bias was computed by averaging the response error over a sliding window (window width: 10°, step size: 1°). Averages with less than ten trials within a subject were excluded before illustration. Again, estimation responses are systematically biased to the previous response. Shaded regions represent 95% confidence intervals