Neural interactions of two slits in the orientation domain in the visual cortical units of the cat.

The responses of the cat's visual cortical cells to an optimally oriented (O-) and an inclined (theta-) slit have been studied. Cell's responses to the simultaneous presentation, in simple cells, are similar to those to theta-slit alone, but in complex cells, are remarkably decreased at orientation difference of about 45 degrees. In the sequential presentation, the effects of preceding theta-slit on the responses to the following O-slit decrease as the orientation difference increases. This suggests that neural interactions of simultaneous and sequential presentation of two slits are caused by different mechanisms.