title: Selective attention modulates high-frequency activity in the face-processing network.
abstract: Face processing depends on the orchestrated activity of a large-scale neuronal network. Its activity can be modulated by attention as a function of task demands. However, it remains largely unknown whether voluntary, endogenous attention and reflexive, exogenous attention to facial expressions equally affect all regions of the face-processing network, and whether such effects primarily modify the strength of the neuronal response, the latency, the duration, or the spectral characteristics. We exploited the good temporal and spatial resolution of intracranial electroencephalography (iEEG) and recorded from depth electrodes to uncover the fast dynamics of emotional face processing. We investigated frequency-specific responses and event-related potentials (ERP) in the ventral occipito-temporal cortex (VOTC), ventral temporal cortex (VTC), anterior insula, orbitofrontal cortex (OFC), and amygdala when facial expressions were task-relevant or task-irrelevant. All investigated regions of interest (ROI) were clearly modulated by task demands and exhibited stronger changes in stimulus-induced gamma band activity (50-150 Hz) when facial expressions were task-relevant. Observed latencies demonstrate that the activation is temporally coordinated across the network, rather than serially proceeding along a processing hierarchy. Early and sustained responses to task-relevant faces in VOTC and VTC corroborate their role for the core system of face processing, but they also occurred in the anterior insula. Strong attentional modulation in the OFC and amygdala (300 msec) suggests that the extended system of the face-processing network is only recruited if the task demands active face processing. Contrary to our expectation, we rarely observed differences between fearful and neutral faces. Our results demonstrate that activity in the face-processing network is susceptible to the deployment of selective attention. Moreover, we show that endogenous attention operates along the whole face-processing network, and that these effects are reflected in frequency-specific changes in the gamma band.
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: kathrin.muesch@gmail.com.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Müsch
authors.affiliation: Laboratoire de Psychologie Cognitive, Aix-Marseille University, Marseille, France. Electronic address: carlos-miguel.hamame@univ-amu.fr.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Hamamé
authors.affiliation: Université Grenoble Alpes, LPNC, Grenoble, France; CNRS, LPNC, UMR, 5105 Grenoble, France. Electronic address: perronemarcela@gmail.com.
authors.forename: Marcela
authors.initials: M
authors.lastname: Perrone-Bertolotti
authors.affiliation: Department of Neurology, Grenoble University Hospital, Grenoble, France. Electronic address: LMinotti@chu-grenoble.fr.
authors.forename: Lorella
authors.initials: L
authors.lastname: Minotti
authors.affiliation: Department of Neurology, Grenoble University Hospital, Grenoble, France. Electronic address: philippe.kahane@ujf-grenoble.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Kahane
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: ak.engel@uke.de.
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Engel
authors.affiliation: INSERM U1028, Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center, Lyon, France; University Claude Bernard, Lyon, France. Electronic address: jp.lachaux@inserm.fr.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lachaux
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: t.schneider@uke.de.
authors.forename: Till R
authors.initials: TR
authors.lastname: Schneider
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005145:Face; D005149:Facial Expression; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010775:Photic Stimulation; D055815:Young Adult
keywords: Amygdala; Emotion; Face processing; Gamma band activity; Intracranial EEG