Perceptual decisions and oculomotor responses rely on temporally distinct streams of evidence

Abstract

Perceptual decisions often require the integration of noisy sensory evidence over time. This process is formalized with sequential sampling models, where evidence is accumulated up to a decision threshold before a choice is made. Although classical accounts grounded in cognitive psychology tend to consider the process of decision formation and the preparation of the motor response as occurring serially, neurophysiological studies have proposed that decision formation and response preparation occur in parallel and are inseparable (Cisek, 2007;Shadlen et al., 2008). To address this serial vs. parallel debate, we developed a behavioural, reverse correlation protocol, in which the stimuli that influence perceptual decisions can be distinguished from the stimuli that influence motor responses. We show that the temporal integration windows supporting these two processes are distinct and largely non-overlapping, suggesting that they proceed in a serial or cascaded fashion.

Serial dependence for oculomotor control depends on early sensory signals

“…Third, the temporal integration of information is different for oculomotor control and perceptual decisions. Although a recent study elegantly demonstrated this difference for single behavioral trials, 18 similar claims have been also made for serial dependence. 19,20 When repeatedly seeing the same movement sequence, perceptual decisions tend to be based on adaptation and integration of information across a longer time period.…”