Functional characteristics of a motion responsive region in the posterior cingulate cortex compared to V5/MT and MST

Motion processing regions apart from V5+/MT+ are still relatively poorly understood. The cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex (dPCC) was previously described to respond preferentially to coherent motion and implied in ego-motion processing. We used fMRI to compare responses of CSv/dPCC and of areas V5/MT and MST to distinct types of motion and self-motion cues such as retinal motion and objective motion, determined during pursuit. Both V5/MT and MST had a strong preference for contra- versus ipsi-lateral stimulation, no preference for 2D planar motion versus 3D flow, and reduced yet significant responses to random motion. In contrast, CSv/dPCC preferred 2D planar motion over 3D flow, showed no lateralization, and did not respond to random motion. All areas responded strongly to eye-movement related signals, however CSv responded more to ‘real’ motion than to retinal motion while the reverse was the case for V5/MT and MST. CSv/dPCC thus differs from other motion-responsive regions by its unique preference to full-field, coherent and planar motion cues and its enhanced capability to respond to real motion. These results place CSv/dPCC in a good position to process visual and non-visual cues related to self-induced motion, especially those associated to eye-movements