title: Facilitative integration of local motion signals in the peripheral visual field observed in monkey ocular following responses.
abstract: To explore how local motion signals in the peripheral visual field are integrated, we recorded ocular following responses (OFRs) to moving vertical gratings extending across a wide horizontal width (1) of various vertical heights, (2) of a thin strip (4° height) at various vertical eccentricities, and (3) of two thin strips separated with various vertical distances (double-grating) in four monkeys. We found that the OFRs became larger and responsive more to lower spatial frequency than to higher as the vertical height of the motion stimuli increased up to 8° or 16°. This result is consistent with the incorporation of visual motion signals originating in the peripheral visual field; the OFRs to thin strips of drifting gratings were tuned for lower spatial frequency as the eccentricity increased. We also found that the OFRs to the double-gratings were quite similar to the sum of the responses to the single gratings in the initial period, but were significantly larger than the linear-sum in the final period. This result suggests that a non-linear mechanism, by which weak local motion signals are integrated into an effective ensemble, underlies the OFRs.
authors: Department of Integrative Brain Science, Graduate School of Medicine, Kyoto University, Japan.
authors: Yuki
authors: Y
authors: Aoki
authors: Kenji
authors: K
authors: Kawano
authors: Kenichiro
authors: K
authors: Miura
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D004558:Electric Stimulation; D008253:Macaca mulatta; D009039:Motion Perception / Q000502:physiology*