Neural Mechanisms for Self-Motion Perception in Area MST

Abstract

Research on the neural circuitry responsible for perception of self-motion has focused on the medial superior temporal area, particularly the dorsal division (MSTd). Cells in this area are selective for the location of the focus of expansion and to pursuit eye movements, two signals necessary for recovering the direction of self-motion (Gibson, 1950). Research reviewed here shows many interesting correlates between the perception of self-motion and the activity of MST neurons. In particular, the focus tuning curves of these cells adjust to take into account motions during eye movements using extra-retinal signals, similar to the results of human perceptional experiments. Eye rotations due to head movements are also compensated for perceptually, and the focus tuning of MST neurons are also compensated for during head-generated eye rotations. Finally, the focus tuning curves compensate for both the direction and the speed of eye rotations, similar to that found in psychophysical studies. However, there are also several aspects of MSTd activity that do not completely mesh with the perception of self-motion; these differences suggest that area MSTd is not the final stage or the only locus of brain activity which accounts for this percept. Finally we offer a "gain field" model, which explains how area MSTd neurons can compensate for gaze rotations.

Additional details