title: Non-monotonic Temporal-Weighting Indicates a Dynamically Modulated Evidence-Integration Mechanism.
abstract: Perceptual decisions are thought to be mediated by a mechanism of sequential sampling and integration of noisy evidence whose temporal weighting profile affects the decision quality. To examine temporal weighting, participants were presented with two brightness-fluctuating disks for 1, 2 or 3 seconds and were requested to choose the overall brighter disk at the end of each trial. By employing a signal-perturbation method, which deploys across trials a set of systematically controlled temporal dispersions of the same overall signal, we were able to quantify the participants' temporal weighting profile. Results indicate that, for intervals of 1 or 2 sec, participants exhibit a primacy-bias. However, for longer stimuli (3-sec) the temporal weighting profile is non-monotonic, with concurrent primacy and recency, which is inconsistent with the predictions of previously suggested computational models of perceptual decision-making (drift-diffusion and Ornstein-Uhlenbeck processes). We propose a novel, dynamic variant of the leaky-competing accumulator model as a potential account for this finding, and we discuss potential neural mechanisms.
authors: School of Psychology, Tel-Aviv University, Tel-Aviv, Israel.|The Cohn Institute for the History and Philosophy of Science and Ideas, Tel-Aviv University, Tel-Aviv, Israel.
authors: Zohar Z
authors: ZZ
authors: Bronfman
authors: School of Psychology, Tel-Aviv University, Tel-Aviv, Israel.
authors: Noam
authors: N
authors: Brezis
authors: School of Psychology, Tel-Aviv University, Tel-Aviv, Israel.|Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.
authors: Marius
authors: M
authors: Usher
mesh_terms: D002755:Choice Behavior / Q000502:physiology*; D019295:Computational Biology; D003657:Decision Making / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D013647:Task Performance and Analysis