Perceptual bias and response bias in temporal bisection.

Abstract

In a temporal bisection task with rats, perceptual bias and response bias were simultaneously varied through manipulations of stimulus spacing and the relative probability of reinforcement for correct responses. Both manipulations produced systematic changes in the bisection point. However, only manipulations of relative reinforcement probability produced significant variations in B″, a nonparametric index of response bias. This finding shows that the bisection point may be shifted by either a perceptual bias or a response bias. However, in the absence of an index of response bias, such as B″, shifts caused by perceptual effects are indistinguishable from those caused by response preferences.