题目：Serial dependencies in rapid stimulus sequences: Evidence for attractive and repulsive adaptation over brief time-scales in multiple sensory modalities

报告人：David Alais,Ph.D. ( School of Psychology, The University of Sydney)

时间：2016年06月23日 星期四 13:00-15:00

地点： Room 1115, Wang kezhen Building

Abstract:Several recent studies have shown that a rapid form of adaptation occurs between trials in rapid sequences of varying stimuli. Sequential effects often produce positive dependencies (perception biased towards the previous stimulus: similar to priming), contrasting with repulsive aftereffects (negative dependencies) seen after sustained exposure to a single stimulus. Here, a review of very recent work together with new experimental data shows that positive dependencies occur strongly in both spatial and temporal domains, both within and between modalities. Effect sizes can be large, with the previous stimulus accounting for up to a third or more of the current response. These findings suggest a process which stabilises current perception by averaging the recent past to produce the positive dependency. This would be beneficial for any attribute that remains largely stable over time (discounting variability as noise) but not for highly variable attributes where signal variation conveys important information. For variable attributes, conventional ‘repulsive’ adaptation provides a better mechanism as it is optimized for detecting change. In experiments that varied the stimulus in two dimensions (one variable attribute, one stable attribute), we found strong dissociation between adaptation effects: a positive dependency for the stable attribute, and a negative one for the variable attribute. The finding that both positive and negative serial dependencies can operate at the same time on the same stimulus suggests a sophisticated flexibility in sensory adaptation.

Host:Huan Luo