Abstract
Decisions across a range of perceptual tasks are known to be biased toward stimuli and choices from the past. So-called serial dependence is thought to be an adaptive low-level mechanism that promotes perceptual stability across visual inputs. However, recent studies suggest post-perceptual mechanisms may instead contribute to serially-biased responses, calling into question the locus of serial dependence and the nature of integration of past and present sensory inputs. Here, we uncover decisional contributions to serial dependence that account for the majority, if not all of the bias. We measured serial dependence in a 3D motion extrapolation task where uncertainty in the sensory information varied from trial to trial. Furthermore, visual and auditory response feedback were provided to a subset of participants on every trial. We found that responses were significantly more biased toward the previously reported motion direction rather than the previously presented direction, with larger biases on trials with greater uncertainty in the sensory input. Critically, response feedback was associated with an abolishment of bias toward the previously presented direction, and a significant reduction of bias toward the previously reported direction. These results provide clear evidence for a post-perceptual locus of serial dependence and support the role of serial dependence as a behavioral strategy to overcome sensory uncertainty.
Competing Interest Statement
The authors have declared no competing interest.
