Size Perception Biases Are Temporally Stable and Vary Consistently Between Visual Field Meridians

Abstract

The apparent size of visual stimuli depends on where in the visual field they appear. We recently presented a model of how size perception could be biased by stimulus encoding in retinotopic cortex. However, it remains unclear if such perceptual biases are instead trivially related to discrimination ability and if they are temporally stable. An independent test of the model is also still outstanding. Here, I show that perceptual biases are stable across stimulus durations between 50 and 1,000 milliseconds, even though discrimination ability unsurprisingly improves with duration. Furthermore, perceptual biases are stronger along the vertical than the horizontal meridian, which mirrors reported differences in spatial vision and the positional selectivity of early visual cortex. Taken together, these findings support our model of how size is inferred from cortical responses.

Perception of the ambiguous motion quartet: a stimulus-observer interaction approach

“…Therefore, we may conclude that there is no clear, meaningful influence of spatial location on the perception of this MQ with AR = 1. Interestingly, in contrast to the current findings, various previous studies have reported an effect of spatial location on the perception of visual stimuli (Moutsiana et al, 2016;Schwarzkopf, 2019;Finlayson et al, 2020). This indicates that perception of different basic visual stimuli is differentially affected by location in the visual field, which would be worthwhile for further exploration.…”

Human perception of spatial frequency varies with stimulus orientation and location in the visual field

“…Our approach is consistent with earlier observations of lower apparent SF for horizontal than for vertical gratings presented along the horizontal meridian 13 , 14 . The proposed link between (low) spatial resolution and (small) apparent size of objects can explain why apparent SF increases with eccentricity 12 , and is in line with the tendency to perceive stimuli as smaller in peripheral compared to central vision as well as along the vertical compared to horizontal meridian 25 , 26 . Because the overall spatial resolution gradually decreases from the horizontal to the vertical meridian (i.e.…”

Cortical magnification eliminates differences in contrast sensitivity across but not around the visual field

“…Might M-scaling eliminate polar angle asymmetries for visual dimensions other than contrast sensitivity? Polar angle asymmetries have been identified for fundamental basic visual properties (e.g., contrast sensitivity; Abrams et al, 2012 ; Baldwin et al, 2012 ; Cameron et al, 2002 ; Himmelberg et al, 2020 ; Pointer and Hess, 1989 ; Silva et al, 2008 ; acuity; Barbot et al, 2021 ; Greenwood et al, 2017 ; Kwak et al, 2023 ; Schwarzkopf, 2019 ; Wang et al, 2020 ), for mid-level properties (e.g., crowding; Greenwood et al, 2017 ; Petrov and Meleshkevich, 2011 ) and texture segmentation ( Barbot et al, 2021 ; Greenwood et al, 2017 ; Kwak et al, 2023 ; Talgar and Carrasco, 2002 ; Wang et al, 2020 ), and for higher-order properties (e.g., speed of information accrual; Carrasco et al, 2004 ; numerosity processing; Chakravarthi et al, 2022 ; face perception; Afraz et al, 2010 ; Peterson and Eckstein, 2013 ; and perceived object size; Schwarzkopf, 2019 ). However, contrast sensitivity is the currency of the visual system, which most – if not all – visual dimensions depend upon in some capacity.…”