Neuronal selectivity and local map structure in visual cortex.
The organization of primary visual cortex (V1) into functional maps makes individual cells operate in a variety of contexts. For instance, some neurons lie in regions of fairly homogeneous orientation preference (iso-orientation domains), while others lie in regions with a variety of preferences (e.g., pinwheel centers). We asked whether this diversity in local map structure correlates with the degree of selectivity of spike responses. We used a combination of imaging and electrophysiology to reveal that neurons in regions of homogeneous orientation preference have much sharper tuning. Moreover, in both monkeys and cats, a common principle links the structure of the orientation map, on the spatial scale of dendritic integration, to the degree of selectivity of individual cells. We conclude that neural computation is not invariant across the cortical surface. This finding must factor into future theories of receptive field wiring and map development.
Nauhaus
Ian
I
Biomedical Engineering Department, University of California, Los Angeles, CA 90095, USA.
Benucci
Andrea
A
Carandini
Matteo
M
Ringach
Dario L
DL
D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002415:Cats; D008252:Macaca fascicularis; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology