title: Facilitated early cortical processing of nude human bodies.
abstract: Functional brain imaging has identified specialized neural systems supporting human body perception. Responses to nude vs. clothed bodies within this system are amplified. However, it remains unresolved whether nude and clothed bodies are processed by same cerebral networks or whether processing of nude bodies recruits additional affective and arousal processing areas. We recorded simultaneous MEG and EEG while participants viewed photographs of clothed and nude bodies. Global field power revealed a peak ∼145ms after stimulus onset to both clothed and nude bodies, and ∼205ms exclusively to nude bodies. Nude-body-sensitive responses were centered first (100-200ms) in the extrastriate and fusiform body areas, and subsequently (200-300ms) in affective-motivational areas including insula and anterior cingulate cortex. We conclude that visibility of sexual features facilitates early cortical processing of human bodies, the purpose of which is presumably to trigger sexual behavior and ultimately ensure reproduction.
authors.affiliation: Brain and Mind Laboratory, Department of Neuroscience and Biomedical Engineering (NBE), School of Science, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland. Electronic address: jussi.alho@aalto.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Alho
authors.affiliation: Brain and Mind Laboratory, Department of Neuroscience and Biomedical Engineering (NBE), School of Science, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland.
authors.forename: Nelli
authors.initials: N
authors.lastname: Salminen
authors.affiliation: Brain and Mind Laboratory, Department of Neuroscience and Biomedical Engineering (NBE), School of Science, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Sams
authors.affiliation: Human Information Processing Laboratory, School of Social Sciences and Humanities/Psychology, University of Tampere, 33014 Tampere, Finland.
authors.forename: Jari K
authors.initials: JK
authors.lastname: Hietanen
authors.affiliation: Brain and Mind Laboratory, Department of Neuroscience and Biomedical Engineering (NBE), School of Science, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland; University of Turku, Department of Psychology and Turku PET Centre, P.O. Box 52, FI-20521 Turku, Finland; MEG Core, Aalto NeuroImaging, Aalto University, P.O. Box 11000, FI-00076 Aalto, Finland; AMI Centre, Aalto NeuroImaging, Aalto University, P.O. Box 11000, FI-00076 Aalto, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Nummenmaa
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D018594:Human Body; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D019529:Sexuality / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: EEG; Human body; MEG; Nude; Visual processing