HUMAN PERCEPTUAL PROCESSING - INHIBITION OF TRANSIENT PREFRONTAL-PARIETAL 40 HZ BINDING AT P300 ONSET DOCUMENTED IN NON-AVERAGED COGNITIVE BRAIN POTENTIALS

Non-averaged scalp-recorded human brain potentials were analyzed durin g selective attention to somatic (finger) sensory stimuli. Distinct co gnitive electrogeneses were identified by numerical assessment of thei r scalp topographical congruities with appropriate templates. The P300 electrogenesis and the 40 Hz neuronal oscillations disclosed, at diff erent scalp sites, variations in timing from trial to trial. However, in any given single trial the transient 40 Hz phase-locking between th e somatic prefrontal and parietal subareas was found to be disrupted a t P300 onset. The results suggest that the P300 cognitive electrogenes is manifests an inhibition of the neurons assemblies involved in the p erceptual processing of the attended sensory input, thereby achieving a 'closure' of the cognitive operations dealing with the currently att ended sensory input. P300 can thus be viewed as one of the physiologic al mechanisms which can control the kinetics of the 40 Hz binding proc ess. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.