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 oscillations (about 0.05 mm) tracked alternations between exclusive dominance phases of the black or white disk. These oscillations 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 oscillations during exclusive dominance phases. This was in spite of the reliable effects of endogenous attention on perceptual dominance, which shifted in favor of the cued percept by about 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.

Flicker pupil perimetry: In search of an objective visual field test for young or neurologically impaired patients

“…This novel view explains why subjectively perceived brightness and the degree of awareness for the presented stimulus rather than its physical properties determine pupil response amplitudes Suzuki et al, 2019). Furthermore, experience with stimulus content , the degree and locus of attention (Acquafredda et al, 2022;Binda & Murray, 2015b;Rosli et al, 2018a), and visual sensitivity (Binda & Murray, 2015a; all shape pupil responses. In summary, a pupillary response amplitude reflects how well a stimulus draws attention and is processed.…”