[Abstract Title]. - Society for Neuroscience

Title: Simultaneous LFP recordings in primate V4 and PF cortex during visual perception of
natural images
Authors: *S. LIEBE, N. K. LOGOTHETIS, G. RAINER;
Dept Physiol Cognitive Proc, MPI Biol. Cybernetics, Tuebingen, Germany
Abstract: Both the extrastriate area V4 and the dorsolateral prefrontal cortex (PFC) play an
important role in the processing of visual information. Their role can be best understood by
examining single unit responses as well as local field potentials (LFPs) that are indicators of
integrative dendro-somatic events. Here, we examine tuning properties of LFPs simultaneously
in both areas during a visual memory task. We first focus on the visual evoked potential (VEP).
We employed a set of natural images as stimuli that were shown in chromatic and achromatic
conditions at different degradation levels.
A majority of recorded sites (110/151 in V4, 91/140 in PF in two monkeys) showed significant
deflections in stimulus-locked averaged LFP waveforms or VEPs in both areas. Across sites, the
VEP in V4 tended to exhibit two peaks with approximate latencies of 80 and 200 ms. In PFC the
VEP was characterized by a unimodal peak at a latency of about 200ms, which corresponded in
terms of its onset dynamics very closely to the late peak in V4 (200 msec). This suggests that the
arrival of sensory information is reflected in an early peak in V4, and that both areas process
information jointly during a period characterized by a late VEP peak.
VEPs in both regions exhibited tuning for stimulus identity and color. In V4 the amplitude of
both peaks carried information about stimulus identity (p