Human V6 Integrates Visual and Extra-Retinal Cues during Head-Induced Gaze Shifts

Andreas Schindler,Andreas Bartels

doi:10.1016/j.isci.2018.09.004

Abstract

SummaryA key question in vision research concerns how the brain compensates for self-induced eye and head movements to form the world-centered, spatiotopic representations we perceive. Although human V3A and V6 integrate eye movements with vision, it is unclear which areas integrate head motion signals with visual retinotopic representations, as fMRI typically prevents head movement executions. Here we examined whether human early visual cortex V3A and V6 integrate these signals. A previously introduced paradigm allowed participant head movement during trials, but stabilized the head during data acquisition utilizing the delay between blood-oxygen-level-dependent (BOLD) and neural signals. Visual stimuli simulated either a stable environment or one with arbitrary head-coupled visual motion. Importantly, both conditions were matched in retinal and head motion. Contrasts revealed differential responses in human V6. Given the lack of vestibular responses in primate V6, these results suggest multi-modal integration of visual with neck efference copy signals or proprioception in V6.

Highlights

A remarkable property of the visual system is its feat to provide us with stable vision despite continuously changing retinal input induced by our movements of eyes, head, and body
Despite this prominent role for head motion in visual stability almost nothing is known about which visual processing stages integrate head motion signals with retinotopic representations as technical limitations have hindered human neuroimaging to study the neural underpinnings of voluntary head movements
We probed each area using the BOLD contrast between congruent and incongruent conditions

Summary

Introduction

A remarkable property of the visual system is its feat to provide us with stable vision despite continuously changing retinal input induced by our movements of eyes, head, and body. Gaze change commands reach eye and head effector muscles at the same time (Bizzi et al, 1971), and human observers compensate for eye- and head-induced self-motion with equal precision (Crowell et al, 1998). Despite this prominent role for head motion in visual stability almost nothing is known about which visual processing stages integrate head motion signals with retinotopic representations as technical limitations have hindered human neuroimaging to study the neural underpinnings of voluntary head movements

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