The temporal integration windows for visual mirror symmetry. (November 2021)

• Record Type: Journal Article
• Authors: Bellagarda, Cayla A.; Dickinson, J. Edwin; Bell, Jason; Badcock, David R.
• Is Part Of: Vision research. Volume 188(2021)
• Page Start: 184
• Page End: 192
• Publication Date: 2021-11
• Subjects: Symmetry -- Temporal integration -- Luminance-polarity -- Orientation; Vision -- Periodicals; 573.88
• DOI: 10.1016/j.visres.2021.07.009
• Languages: English
• ISSNs: 0042-6989

Abstract

Highlights: Mirror symmetry detection mechanisms are sensitive to temporal delay. Matched-polarity patterns have lower thresholds but greater delay sensitivity. Unmatched-polarity patterns have higher thresholds but less delay sensitivity. Symmetry integration windows suggest dual first- and second-order mechanisms. Symmetry integration windows not consistent with attentional mechanisms. Abstract: Symmetry perception in dot patterns is tolerant to temporal delays of up to 60 ms within and between element pairs. However, it is not known how factors effecting symmetry discrimination in static patterns might affect temporal integration in dynamic patterns. One such feature is luminance polarity. Using dynamic stimuli with increasing temporal delay (SOA) between the onset of the first and second element in a symmetric pair, we investigated how four different luminance-polarity conditions affected the temporal integration of symmetric patterns. All four luminance polarity conditions showed similar upper temporal limits of approximately 60 ms. However psychophysical performance over all delay durations showed significantly higher symmetry thresholds for unmatched-polarity patterns at short delays, but also significantly less sensitivity to increasing temporal delay relative to matched-polarity patterns. These varying temporal windows are consistent with the involvement of a fast, sensitive first-order mechanism for matched-polarity patterns, and a slower, more robust second-order mechanism for unmatched-polarity patterns. Temporal integration windows for unmatched-polarity patterns were not consistent with performance expected from attentional mechanisms alone, and instead supports the involvement of second-order mechanisms that combines information from ON and OFF channels.