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Article

Speed tuning properties of mirror symmetry detection mechanisms

Citation
Sharman R & Gheorghiu E (2019) Speed tuning properties of mirror symmetry detection mechanisms. Scientific Reports, 9, Art. No.: 3431. https://doi.org/10.1038/s41598-019-39064-x

Abstract
The human visual system is often tasked with extracting image properties such as symmetry from rapidly moving objects and scenes. The extent to which motion speed and symmetry processing mechanisms interact is not known. Here we examine speed-tuning properties of symmetry detection mechanisms using dynamic dot-patterns containing varying amounts of position and local motion-direction symmetry. We measured symmetry detection thresholds for stimuli in which symmetric and noise elements either drifted with different relative speeds, were relocated at different relative temporal frequencies or were static. We also measured percentage correct responses under two stimulus conditions: a segregated condition in which symmetric and noise elements drifted at different speeds, and a non-segregated condition in which the symmetric elements drifted at two different speeds in equal proportions, as did the noise elements. We found that performance (i)improved gradually with increasing the difference in relative speed between symmetric and noise elements, but was invariant across relative temporal frequencies/lifetime duration differences between symmetric and noise elements, (ii)was higher in the segregated compared to non-segregated conditions, and in the moving compared to the static conditions. We conclude that symmetry detection mechanisms are broadly tuned to speed, with speed-selective symmetry channels combining their outputs by probability summation.

Journal
Scientific Reports: Volume 9

StatusPublished
Author(s)Sharman, Rebecca; Gheorghiu, Elena
FundersThe Wellcome Trust
Publication date31/03/2019
Publication date online05/03/2019
Date accepted by journal15/01/2019
URLhttp://hdl.handle.net/1893/28937
Related URLshttp://hdl.handle.net/11667/122
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