title: Additive effects of affective arousal and top-down attention on the event-related brain responses to human bodies.
abstract: The early visual event-related 'N170 response' is sensitive to human body configuration and it is enhanced to nude versus clothed bodies. We tested whether the N170 response as well as later EPN and P3/LPP responses to nude bodies reflect the effect of increased arousal elicited by these stimuli, or top-down allocation of object-based attention to the nude bodies. Participants saw pictures of clothed and nude bodies and faces. In each block, participants were asked to direct their attention towards stimuli from a specified target category while ignoring others. Object-based attention did not modulate the N170 amplitudes towards attended stimuli; instead N170 response was larger to nude bodies compared to stimuli from other categories. Top-down attention and affective arousal had additive effects on the EPN and P3/LPP responses reflecting later processing stages. We conclude that nude human bodies have a privileged status in the visual processing system due to the affective arousal they trigger.
authors.affiliation: Human Information Processing Laboratory, School of Social Sciences and Humanities, FIN-33014 University of Tampere, Finland. Electronic address: jari.hietanen@uta.fi.
authors.forename: Jari K
authors.initials: JK
authors.lastname: Hietanen
authors.affiliation: Human Information Processing Laboratory, School of Social Sciences and Humanities, FIN-33014 University of Tampere, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Kirjavainen
authors.affiliation: Brain Research Unit, O.V. Lounasmaa Laboratory, Aalto University School of Science and Technology, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Nummenmaa
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005145:Face; D005260:Female; D018594:Human Body; D006801:Humans; D008297:Male; D009715:Nudism; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Arousal; Attention; EEG; EPN; LPP; N170; Object-based attention; P3; Visual body processing