Face specific broadband electrocorticographic spectral power change in the rhinal cortex

Abstract

Recent studies have revealed additional face areas in the anterior temporal lobe in addition to the ‘core’ face areas (fusiform face area, occipital face area, and face area in the superior temporal sulcus). The electrocorticogram of a patient who underwent implantation of subdural grid electrodes in the right anterior ventral temporal lobe revealed a strong face-specific response both in event-related potentials (ERP) and in the induced broadband spectral power change at an electrode located on the anterior collateral sulcus, straddling the border between the perirhinal and entorhinal cortices. The ERP and induced broadband power changes were highly specific to facial stimuli, which was obvious even in a single trial analysis. The face-specific response was recorded in an area with perfect overlap of the ‘anterior temporal face patch’ in the anterior collateral sulcus, proposed based on human functional magnetic resonance imaging (fMRI) results. A recent fMRI study in monkeys reported a face-specific visual response in the rhinal cortex, suggesting that the basic structural configuration of face responsive areas are preserved across species. Although the rhinal cortex has long been regarded as part of the memory system, recent data suggest that it also plays a role in perception. The face-specific response in the present study might reflect visual processing based on complex conjunctions of visual features required for facial processing.