Embodied spatial cognition lab
... we put the eyes back in vIsIon
Without an accurate knowledge of the rotation of one's own eyes in the orbit, it would be virtually impossible to reach to a cup, to match a voice to a face in a crowd based on their common location or to recognize large visual scenes from multiple retinal snapshots. Retinal information is insufficient for an accurate perception of object location.
The same retinal projection can correspond to different locations in the visual space, depending on the direction of gaze.
So gaze knowledge helps align vision with the motor space and with the other sensory modalities, such as touch or audition.
Research in our lab aims to uncover how neural representations of space that support attention, reaching or object recognition emerge from basic sensorimotor signals and whether a failure to integrate these signals cause neuropsychological disease.
In our recent paper, a former PhD student in our lab, Barthel Odoj, and I report that an eye rotation signal in the somatosensory cortex (oculoproprioception) is specific for spatial attention. This signal is less important for locating external objects (where to reach) and more important for allocating internal priorities for perception (where to attend).
This discovery is exciting not only because it shows that a basic sensorimotor signal can play a selective role in cognition rather than in movement control, but also because it indicates a potential disease mechanism in spatial neglect. Spatial neglect is a common disorder in stroke survivors characterized by a lateral displacement in the focus of attention, often to the right of the body midline. Could spatial neglect reflect an error in the cortical eye proprioceptive signal ? Our research predicts that such an error would selectively impact on the brain's priority maps. Could one treat spatial neglect by targetting this signal ?
To understand better how eye and attention are coupled, PhD student Alex Mitchell is now investigating the connectivity between the brain areas that host oculomotor signals and the brain areas that control the allocation of attention in space.
We hope to have some answers soon, so stay tuned!