Attention Cueing in Rivalry: Insights from Pupillometry

Abstract

We used pupillometry to evaluate the effects of attention cueing on perceptual bi-stability, as reported by adult human observers. Perceptual alternations and pupil diameter were measured during two forms of rivalry, generated by presenting a white and a black disk to the two eyes (binocular rivalry) or splitting the disks between eyes (interocular grouping rivalry). In line with previous studies, we found that subtle pupil size modulations (;0.05 mm) tracked alternations between exclusive dominance phases of the black or white disk. These pupil responses were larger for perceptually stronger stimuli: presented to the dominant eye or with physically higher luminance contrast. However, cueing of endogenous attention to one of the rivaling percepts did not affect pupil modulations during exclusive dominance phases. This was observed despite the reliable effects of endogenous attention on perceptual dominance, which shifted in favor of the cued percept by ;10%. The results were comparable for binocular and interocular grouping rivalry. Cueing only had a marginal modulatory effect on pupil size during mixed percepts in binocular rivalry. This may suggest that, rather than acting by modulating perceptual strength, endogenous attention primarily acts during periods of unresolved competition, which is compatible with attention being automatically directed to the rivaling stimuli during periods of exclusive dominance and thereby sustaining perceptual alternations.

Adaptation to numerosity affects the pupillary light response

“…In illusory 3D stimuli, the pupil modulation tracks the polarity of the surface perceived to be in front, and the magnitude of this modulation varied with the local–global perceptual style, as measured with the by the Autism-Spectrum Quotient (AQ) questionnaire in neurotypical adults 47 , 48 . Other studies using binocular rivalry and interocular grouping rivalry evoking alternations between dark or bright percepts found that pupil size modulations tracked alternations between dominance phases, even though the physical stimulation did not change 49 , 50 .…”

Measuring the reliability of binocular rivalry

“…and C.L.) took part in experiment 2 ( Acquafredda, Binda, & Lunghi, 2022 ). Thirty-four volunteers, mean age 23.9 ± 0.79 years, 24 females (including authors C.L.…”