title: Gamma oscillations distinguish mere exposure from other likability effects.
abstract: Repeated exposure to neutral stimuli enhances liking for those, which is called mere exposure effect (MEE) (Zajonc, 1968). Its behavioral effects have been extensively investigated. However, the mechanism by which it is generated remains unclear. To elucidate the neural mechanism of the MEE, we recorded electroencephalograms while subjects indicated their preferences for face stimuli with and without MEE induction. According to behavioral data, participants were divided into two groups, one with, and one without MEE tendency. In participants with an MEE tendency, gamma activity (40-60 [Hz]) in the parieto-occipital area was significantly weaker for exposed faces than unexposed ones, indicating a repetition-suppression effect. Gamma activity from sites exhibiting peak repetition-suppression effects was significantly weaker in theoretically genuine MEE trials than non-MEE trials, indicating that emotion processing might influence the MEE. These results suggest that existing theories regarding mechanisms underlying the MEE, namely, fluency misattribution and apprehensiveness reduction might not be mutually exclusive. Moreover, gamma activity might be a potential indicator to distinguish the MEE from other likability effects, at least in the case of human face stimuli.
authors.affiliation: Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku, Toyohashi, Aichi 441-8580, Japan.
authors.forename: Nutchakan
authors.initials: N
authors.lastname: Kongthong
authors.affiliation: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku, Toyohashi, Aichi 441-8580, Japan. Electronic address: minami@tut.jp.
authors.forename: Tetsuto
authors.initials: T
authors.lastname: Minami
authors.affiliation: Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku, Toyohashi, Aichi 441-8580, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nakauchi
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology; D003657:Decision Making / Q000502:physiology; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D005071:Evoked Potentials; D005145:Face; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology; D013647:Task Performance and Analysis; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*
keywords: Face stimuli; Gamma band oscillation; Mere exposure effect; Preferential decision