SPATIAL AND TEMPORAL MATCHING OF RECEPTIVE-FIELD PROPERTIES OF BINOCULAR CELLS IN AREA-19 OF THE CAT

The spatial and temporal properties of single neurons were investigate d in area 19 of the cat. We evaluated the matching of binocular recept ive held properties with regard to the respective strength of the ipsi lateral and contralateral inputs. Results indicate that most cells in area 19 are well tuned to spatial and temporal frequencies and exhibit relatively low contrast threshold (mean=6.8%) when assessed using opt imal parameters and tested through the dominant eye. Spatial resolutio n (mean=0.75 c/degrees), optimal spatial frequencies (mean=0.16 c/degr ees) were relatively low and spatial bandwidths (mean=2.1 octaves) wer e broader as compared to those of cells in area 17 but comparable to t hose of cells in other extrastriate areas. On the other hand temporal resolution (mean=10.7 Hz), optimal temporal frequency (mean=4.5 Hz) an d temporal bandwidths (mean=2.9 octaves) were higher and broader than in primary visual cortex. A significant relationship exists between mo st of the cell's properties assessed through either eye. For some para meters, such as spatial and temporal resolution, ocular dominance was shown to be significantly related to the extent of matching between th e two eyes. For these parameters, binocular cells that exhibited a bal anced ocular dominance were generally well matched with regard to the receptive field properties of each eye whereas the largest mismatches were found in cells that were more strongly dominated by one eye. Thes e results suggest that visual input contributes to the activation of c ells in area 19 in a redundant manner, possibly attesting to the multi plicity of parallel pathways to this area in the cat. (C) 1998 IBRO. P ublished by Elsevier Science Ltd.