Abstract
Ensemble representation is thought to facilitate visual processing and avoid information overload, but it may also bias the representation of individual items. When asked to adjust a probe to match the feature of a single target stimulus, subjects' responses were biased towards the mean of previously viewed but task-irrelevant stimuli, without any explicit requirement of engaging ensemble representation. We asked whether this obligatory bias towards the mean occurs across different categories of stimuli and tested it using two visual features (line length and spatial frequency). Our results showed that the bias towards the mean was evident in spatial frequency. However, we did not find a consistent bias towards the mean in line length in multiple conditions with different starting probe values, probe locations, and distributions of the overall stimuli. This may suggest a specificity of stimulus type of the implicit ensemble bias.
Meeting abstract presented at VSS 2018