Spatio-temporal frequency separability in area 18 neurons of the cat

Spatial frequency tuning curves were obtained at a series of temporal frequencies and/or velocities from neurons of Areas 17 and 18 of the cat, in order to assess the interaction between these spatial and temporal parameters. In the great majority of instances, for neurons in both Areas 17 and 18, we found the optimal spatial frequency invariant with the temporal frequency or velocity at which a neuron was tested. Thus in this respect, responses of neurons in Area 18, like those of Area 17, are separable in their dependence on spatial and temporal frequency.