title: Basic instinct undressed: early spatiotemporal processing for primary sexual characteristics.
abstract: This study investigates the spatiotemporal dynamics associated with conscious and non-conscious processing of naked and dressed human bodies. To this effect, stimuli of naked men and women with visible primary sexual characteristics, as well as dressed bodies, were presented to 20 heterosexual male and female participants while acquiring high resolution EEG data. The stimuli were either consciously detectable (supraliminal presentations) or were rendered non-conscious through backward masking (subliminal presentations). The N1 event-related potential component was significantly enhanced in participants when they viewed naked compared to dressed bodies under supraliminal viewing conditions. More importantly, naked bodies of the opposite sex produced a significantly greater N1 component compared to dressed bodies during subliminal presentations, when participants were not aware of the stimulus presented. A source localization algorithm computed on the N1 showed that the response for naked bodies in the supraliminal viewing condition was stronger in body processing areas, primary visual areas and additional structures related to emotion processing. By contrast, in the subliminal viewing condition, only visual and body processing areas were found to be activated. These results suggest that naked bodies and primary sexual characteristics are processed early in time (i.e., <200 ms) and activate key brain structures even when they are not consciously detected. It appears that, similarly to what has been reported for emotional faces, sexual features benefit from automatic and rapid processing, most likely due to their high relevance for the individual and their importance for the species in terms of reproductive success.
authors.affiliation: Laboratory of Experimental Neuropsychology, Neuropsychology Unit, Neurology Clinic, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Lore B
authors.initials: LB
authors.lastname: Legrand
authors.forename: Marzia
authors.initials: M
authors.lastname: Del Zotto
authors.forename: Rémi
authors.initials: R
authors.lastname: Tyrand
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Pegna
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003243:Consciousness / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D018594:Human Body; D006801:Humans; D007323:Instinct; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D012727:Sex Characteristics; D014473:Unconscious, Psychology; D055815:Young Adult
references.citation: Int J Psychophysiol. 1994 Oct;18(1):49-65
references.pmid: 7876038
references.citation: Proc Natl Acad Sci U S A. 2004 Nov 23;101(47):16701-6
references.pmid: 15546983
references.citation: Prog Neurobiol. 2012 Jul;98(1):49-81
references.pmid: 22609047
references.citation: J Neurophysiol. 2007 Sep;98(3):1626-33
references.pmid: 17596425
references.citation: Psychophysiology. 2008 Mar;45(2):318-26
references.pmid: 17995905
references.citation: Neuropsychologia. 1971 Mar;9(1):97-113
references.pmid: 5146491
references.citation: Am J Public Health. 2003 Jun;93(6):894-8
references.pmid: 12773346
references.citation: Science. 2001 Sep 28;293(5539):2470-3
references.pmid: 11577239
references.citation: Neuroimage. 2010 Jan 15;49(2):1717-27
references.pmid: 19804836
references.citation: Neuron. 2001 Jun;30(3):829-41
references.pmid: 11430815
references.citation: Soc Cogn Affect Neurosci. 2012 Nov;7(8):924-36
references.pmid: 22006991
references.citation: Cogn Affect Behav Neurosci. 2012 Mar;12(1):115-39
references.pmid: 21964552
references.citation: Soc Cogn Affect Neurosci. 2007 Dec;2(4):274-83
references.pmid: 18985133
references.citation: Cereb Cortex. 2012 Jul;22(7):1564-76
references.pmid: 21893680
references.citation: Nat Rev Urol. 2012 Sep;9(9):486-98
references.pmid: 22926422
references.citation: Int J Psychophysiol. 2008 Nov;70(2):127-36
references.pmid: 18804496
references.citation: J Sex Res. 2003 May;40(2):134-45
references.pmid: 12908121
references.citation: Neuroreport. 2004 Apr 9;15(5):777-80
references.pmid: 15073513
references.citation: Nat Rev Neurosci. 2007 Aug;8(8):636-48
references.pmid: 17643089
references.citation: J Cogn Neurosci. 2005 Aug;17(8):1328-40
references.pmid: 16197687
references.citation: Biol Psychol. 2008 Oct;79(2):200-8
references.pmid: 18541359
references.citation: PLoS One. 2008 Jan 30;3(1):e1506
references.pmid: 18231593
references.citation: Neuroimage. 2006 Nov 1;33(2):689-99
references.pmid: 16962339
references.citation: Neuroimage. 2008 Sep 1;42(3):1142-50
references.pmid: 18598769
references.citation: J Comp Neurol. 2005 Dec 5;493(1):154-66
references.pmid: 16254997
references.citation: Electroencephalogr Clin Neurophysiol. 1980 Jun;48(6):609-21
references.pmid: 6155251
references.citation: J Neurosci. 2010 Sep 29;30(39):13095-104
references.pmid: 20881127
references.citation: Nature. 1998 Jun 4;393(6684):467-70
references.pmid: 9624001
references.citation: J Neurosci. 2005 Nov 23;25(47):11055-9
references.pmid: 16306418
references.citation: Neurosci Biobehav Rev. 2012 Jul;36(6):1481-509
references.pmid: 22465619
references.citation: Cereb Cortex. 2006 Oct;16(10):1453-61
references.pmid: 16339084
references.citation: PLoS One. 2011;6(11):e24408
references.pmid: 22110574
references.citation: J Exp Psychol Hum Percept Perform. 2010 Dec;36(6):1477-85
references.pmid: 20695695
references.citation: Neuron. 2012 Feb 23;73(4):653-76
references.pmid: 22365542
references.citation: Nat Rev Neurosci. 2005 Sep;6(9):691-702
references.pmid: 16136173
references.citation: Hum Brain Mapp. 2010 Jul;31(7):1089-105
references.pmid: 20017134
references.citation: J Neurosci. 2007 Jan 31;27(5):1082-9
references.pmid: 17267562
references.citation: Behav Brain Funct. 2008 Jul 22;4:30
references.pmid: 18647397
references.citation: Front Hum Neurosci. 2012 May 01;6:108
references.pmid: 22557958
references.citation: Neurosci Biobehav Rev. 2010 Mar;34(4):513-27
references.pmid: 19857515
references.citation: Nat Neurosci. 2005 Jan;8(1):24-5
references.pmid: 15592466
references.citation: Neuroimage. 2003 Oct;20(2):855-69
references.pmid: 14568457
references.citation: Brain Res. 2006 Jun 6;1093(1):167-77
references.pmid: 16712815
references.citation: Psychoneuroendocrinology. 2005 Jun;30(5):461-82
references.pmid: 15721058
references.citation: Psychophysiology. 2004 May;41(3):441-9
references.pmid: 15102130
references.citation: Proc Natl Acad Sci U S A. 1999 Feb 16;96(4):1680-5
references.pmid: 9990084
references.citation: Neuropsychologia. 2008 Feb 12;46(3):774-85
references.pmid: 18037456
references.citation: Proc Natl Acad Sci U S A. 2006 Nov 7;103(45):17048-52
references.pmid: 17075055
references.citation: Brain. 1998 Jan;121 ( Pt 1):47-57
references.pmid: 9549487
references.citation: J Neurosci. 2004 Jun 16;24(24):5500-5
references.pmid: 15201322
references.citation: PLoS One. 2010 Feb 05;5(2):e9042
references.pmid: 20140088
references.citation: Neuroimage. 2006 Aug 15;32(2):871-9
references.pmid: 16750639
references.citation: Clin Neurophysiol. 2004 Oct;115(10):2195-222
references.pmid: 15351361
references.citation: Brain Res. 2007 Dec;1186:233-41
references.pmid: 17996856
references.citation: Nat Neurosci. 2004 Nov;7(11):1271-8
references.pmid: 15494727