Perception Action Cognition Occasional Talks
Eye position signals in spatial cognition
The straightforward sense of where things are belies the hard problem of aligning input from mobile sensory organs with one another and with the action space of the body. Without information about the rotation of the eyes within the head, for instance, it would be virtually impossible to match an unknown face and a voice in a crowd or to reach to visual targets without seeing the hand. There are two main signals of eye position. The copy of the command sent to the extraocular muscles (corollary discharge) is predictive, therefore faster. The reafference from these muscles (proprioception) is slower, but more accurate. In my talk I will present evidence that these signals are used flexibly, depending on behavioral goals. Locating objects relative to the body, for instance to guide a movement, relies mainly on the fast signal, corollary discharge . In contrast, eye proprioception seems to be more important for perception, ie allocating attention in the body-centered space.