Time course of gamma‐band oscillation associated with face processing in the inferior occipital gyrus and fusiform gyrus: A combined fMRI and MEG study

Abstract

Debate continues over whether the inferior occipital gyrus (IOG) or the fusiform gyrus (FG) represents the first stage of face processing and what role these brain regions play. We investigated this issue by combining functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in normal adults. Participants passively observed upright and inverted faces and houses. First, we identified the IOG and FG as face-specific regions using fMRI. We applied beamforming source reconstruction and time-frequency analysis to MEG source signals to reveal the time course of gamma-band activations in these regions. The results revealed that the right IOG showed higher gamma-band activation in response to upright faces than to upright houses at 100 ms from the stimulus onset. Subsequently, the right FG showed greater gamma-band response to upright faces versus upright houses at around 170 ms. The gamma-band activation in the right IOG and right FG was larger in response to inverted faces than to upright faces at the later time window. These results suggest that (1) the gamma-band activities occurs rapidly first in the IOG and next in the FG and (2) the gamma-band activity in the right IOG at later time stages is involved in configuration processing for faces. Hum Brain Mapp 38:2067-2079, 2017. © 2017 Wiley Periodicals, Inc.

Bidirectional electric communication between the inferior occipital gyrus and the amygdala during face processing

“…Several previous functional neuroimaging studies have reported that the FG is active during the observation of faces [e.g., Haxby et al, ; Sergent et al, ; for a review, see Kanwisher and Yovel, ]. Intracranial EEG [Engell and McCarthy, ; Klopp et al, ; Lachaux et al, ] and MEG [Uono et al, ] studies reported that this region exhibits gamma‐band activation in response to faces. However, the manner in which the FG may contribute to the functional network that includes the IOG and amygdala remains unknown.…”

Theta- and Gamma-Band Activity Discriminates Face, Body and Object Perception

“…Evidence suggests that enhanced gamma oscillations are induced by faces over occipito-temporal areas when compared to control stimuli such as houses or scrambled stimuli (Zion-Golumbic and Zion-Golumbic et al, 2008;Gao et al, 2012). Since these oscillations show a physiological FIE (i.e., upright faces induced enhanced synchronization in gamma-band oscillations when compared to inverted faces), this activity likely reflects the difficulty of the visual system to bind facial features of inverted faces (i.e., holistic processing is not engaged by inverted stimuli) in a configural representation (Lachaux et al, 2005;Anaki et al, 2007;Dobel et al, 2011;Moratti et al, 2014;Matsuzaki et al, 2015;Uono et al, 2017). In line with behavioral results, even non-face stimuli (i.e., objects) show a physiological inversion effect, albeit of smaller magnitude (Tallon-Baudry and Bertrand, 1999).…”

Frequency-Dependent Changes of the Resting BOLD Signals Predicts Cognitive Deficits in Asymptomatic Carotid Artery Stenosis

“…In medial temporal lobe, parahippocampal gyrus is a gray matter layer around the hippocampus, which plays an important role in the encoding and extraction of memory ( Megevand et al, 2014 ). Additionally, olfactory region in parahippocampal gyrus is the gate linking to the hippocampus with rich incoming connections; fusiform gyrus is linked to the function including color information processing and the recognition of face, body, and word ( Uono et al, 2017 ).…”