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Sulewski, P.

Publications and source records attributed to Sulewski, P..

2 recordsLinked to original sources

Predictive remapping and allocentric coding as consequences of energy efficiency in recurrent neural network models of active vision

Despite moving our eyes from one location to another, our perception of the world is stable - an aspect thought to rely on predictive computations that use efference copies to predict the upcoming foveal input. Are these complex computations genetically hard-coded, or can they emerge from simpler principles? Here we consider the organisms limited energy budget as a potential origin. We expose a recurrent neural network to sequences of fixation patches and saccadic efference copies, training the model to minimise energy consumption (preactivation). We show that targeted inhibitory predictive remapping emerges from this energy efficiency optimization alone. As furthermore demonstrated, this computation relies on the models learned ability to re-code egocentric eye-coordinates into an allocentric (imagecentric) reference frame. Together, our findings suggest that both allocentric coding and predictive remapping can emerge from energy efficiency constraints during active vision, demonstrating how complex neural computations can arise from simple physical principles.

neuroscience↗

Saccade onset, not fixation onset, best explains early sensory responses across the human visual cortex during naturalistic vision

Visual processing is traditionally studied using static viewing paradigms in which researchers analyse brain responses to the onsets of a sequence of randomly selected stimuli. Translating this "stimulus onset" approach to active vision paradigms that allow for free eye-movements, researchers often consider fixation onsets as the events that trigger visual activity across the visual system. Here, we test this assumption by analysing a large-scale magnetoencephalography (MEG) dataset with simultaneously recorded eye movements of 5 participants who freely explored thousands of natural images, yielding approximately 200,000 gaze events. We show that saccade-related events, particularly peak saccade curvature, rather than fixation onsets, explain most variance in latency of the early sensory component M100. Further, comparing the classic M100 elicited by stimulus onsets with the M100s elicited during active vision revealed stark differences, both in response to saccade-related and fixation-onset events. This indicates that phenomena discovered using gold standard stimulus onset paradigms do not necessarily translate to natural vision. Our findings challenge the prevailing approach to studying vision in static paradigms and highlight the importance of internally generated and action-driven signals in the dynamics of natural sensory processing.

neuroscience↗