Organization of texture segregation processing in primate visual cortex

Investigated which cortical areas and layers are involved in global feature interactions underlying texture segregation in humans and monkeys. Visual stimulation was assessed with an electrostatic monitor, and scalp or intracortical recordings with electrodes were made. Signal processing and psychophysical testing were also performed. Evoked potentials (EPs) were recorded to a stimulus, signalling a contribution from texture segregation-sensitive mechanisms by means of specific response components (SRCs). Equivalent dipole estimations of the SRCs suggest the presence of texture segregation-related activity in the primary visual cortex of human Ss. Results were corroborated by current-source-density analysis of intracortical recordings in the awake monkey. A specific involvement of layers 2/3 and 5 of Area 17 in the global process of image segmentation was demonstrated.