Active vision modulates early cortical stages of visual processing: Evidence from MEG and eye-tracking

Vision is fundamentally active. Humans and other mammals make several saccadic eye movements per second. This feature of mammalian vision has received increasing interest across the last decades and many behavioural and neurophysiological studies have investigated how the visual system accounts for the effects of self-generated motion (efference copy) in perceptual processing. Still, it is often believed that, besides accounting for the efference copy and for the rhythmic modulation of activity due to perpetual saccade-fixation cycles, active vision does not further modulate neural processing of visual input obtained during periods of fixation. In contrast, using a gaze-contingent trans-saccadic change design with concurrent MEG and eye-tracking data recording from human participants, we find sequential history effects in visual cortices. Harnessing the preview effect, we show that primary visual and ventral occipital cortices respond differently when eye-movements bring objects into focus compared to when the same objects appear during steady fixation. Specifically, we find that sequential modulations of cortical processing across saccades, in the form of preview effects, are increased during active vision compared to steady-gaze control conditions. Our data also show that these sequential modulations cannot be explained by any type of adaptation alone. Our study, therefore, provides an update on the role of active vision in modulating cortical function.