Clustering of selectivity for optic flow in the ventral intraparietal area.

The presence of a columnar or clustered organization for some property often denotes that this property is important to the local information processing in a cortical area. To determine whether self-motion is systematically organized in the ventral intraparietal area (VIP), we made long electrode penetrations, recording both multi-unit and single-unit tuning for horizontally varying heading stimuli at frequent intervals. Single units were well correlated with the tuning of multi-unit activity at the same location and multi-unit activity was more correlated with tuning at nearby locations than it was with tuning at locations beyond approximately 0.5 mm. From this, we conclude that heading information is represented in a clustered, and possibly columnar, fashion in VIP.