Purchase this article with an account.
Michael Dorr, Thomas S Wallis, Peter J Bex; Visual sensitivity under naturalistic viewing conditions. Journal of Vision 2014;14(10):1448. doi: https://doi.org/10.1167/14.10.1448.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Psychophysical experiments typically use very simple stimuli, such as isolated dots and gratings on uniform backgrounds, and allow no or only very stereotyped eye movements. While these viewing conditions are highly controllable, they are not representative of real-world vision, which is characterized by a complex, broadband input and several eye movements per second. We performed a series of experiments in which subjects freely watched high-resolution nature documentaries and TV shows on a gaze-contingent display. Eye-tracking at 1000 Hz and fast video processing routines allowed us to precisely modulate the stimulus in real time and in retinal coordinates. The task then was to locate either bandpass contrast changes or geometric distortions that briefly appeared in one of four locations relative to the fovea every few seconds. We confirm a well-known loss of sensitivity when video modulations took place around the time of eye movements, i.e. around episodes of high-speed retinal motion. However, we found that replicating the same retinal input in a passive condition, where subjects maintained central fixation and the video was shifted on the screen, led to a comparable loss in sensitivity. We conclude that no process of active, extra-retinal suppression is needed to explain peri-saccadic visual sensitivity under naturalistic conditions. We further find that the detection of spatial modifications depends on the spatio-temporal structure of the underlying scene, such that distortions are harder to detect in areas that vary rapidly across space or time. These results highlight the importance of naturalistic assessment for understanding visual processing.
Meeting abstract presented at VSS 2014
This PDF is available to Subscribers Only