The growing sensory suppression on visual perception during head-rotation preparation

Sensory perception is often impaired by self-generated movements. This effect of sensory suppression has been commonly observed in voluntary hand-movement-induced tactile sensation during the period of motor preparation and execution. However, it remains unclear whether such suppression also occurs in the visual domain and if it can be induced by the preparation of other body movements. To extend our knowledge about sensory suppression, the present study investigated visual sensitivity during the preparation of head rotation. Participants wore virtual reality goggles and rotated their heads horizontally according to a visual cue presented on the goggles screens. Before the start of head rotation, a target of Landolt C was displayed at a peripheral location that was directed by the head-rotation cue or a symmetric location in the opposite visual field. After each head rotation, participants reported the target's orientation, allowing the measurement of the discrimination threshold. Besides, the discrimination sensitivity was also measured in two head-still conditions with or without the presentation of a visual cue. The results showed that the discrimination performance was largely impaired by the preparation of head rotation. This effect of sensory attenuation increased with the approach of head-motion onset. However, the attenuation was not found on the discrimination of auditory stimuli during the preparation of head rotation, thus excluding the account of general dual-task requirement. In contrast to the previous findings of improved perception by preparation of saccade or reach, our findings indicate that sensory suppression rather than attention shift plays a major role during the preparation of head movement.