Seeing at Will: Shared Neural Representations of Motion Perception and Intention

Abstract

Intention can bias perception in cases where two or more interpretations of a stimulus are possible. The neural mechanisms whereby intention influences perception are poorly understood. Here we investigated whether the intention to perceive horizontal or vertical motion in a bistable apparent motion stimulus pre-activates motion axes representations in sensory cortex before the position shift occurs and before motion in consciously perceived. Twelve participants underwent fMRI scanning under three conditions: (1) passively viewing quartet stimuli moving continuously along veridical trajectories; (2) passively viewing bistable apparent motion quartet stimuli induced by two pairs of squares alternately flashing at diagonally opposite corners of an invisible rectangle; or (3) while actively intending to perceive a single-shot apparent-motion stimulus as moving either vertically or horizontally. Multivariate decoding analyses revealed that activity patterns during the intention period of (3) generalized to patterns evoked by both (1) physical and (2) ambiguous motion perception. Cross-decoding was strongest within dorsal/lateral visual regions, including hMT+, V3AB, and the intraparietal sulcus, but was largely absent from ventral visual cortex. Widespread overlap was also observed between intention-related and perceptual motion representations throughout the dorsal/lateral visual cortex. Our findings suggest that intention may bias prospective sensory representations prior to the stimulus-driven processing that results in perceptual experience and that these representations closely resemble those associated with illusory motion perception. The fact that intention-related representations were mostly found within dorsal/lateral visual regions is consistent with top-down influences from attentional control systems.