title: Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.
abstract: Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex.
authors: Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892 wchan2@uthsc.edu.
authors: Annie W-Y
authors: http://orcid.org/0000-0001-9072-9222
authors: AW
authors: Chan
authors: Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892.
authors: Chris I
authors: http://orcid.org/0000-0001-6861-8964
authors: CI
authors: Baker
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D005385:Fingers / Q000294:innervation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*; D010812:Physical Stimulation; D013003:Somatosensory Cortex / Q000098:blood supply / Q000502:physiology*; D014110:Touch; D014785:Vision, Ocular; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: action; empathy; hands; human fMRI; touch; vision
references: J Neurosci. 2009 Sep 16;29(37):11523-39
references: 19759300
references: J Cogn Neurosci. 2011 Jul;23(7):1808-22
references: 20666597
references: Hum Brain Mapp. 2014 Jan;35(1):213-26
references: 22965769
references: J Neurosci. 2008 Aug 13;28(33):8361-75
references: 18701699
references: Proc Natl Acad Sci U S A. 2012 Oct 30;109(44):18114-9
references: 23071340
references: J Neurophysiol. 2007 Sep;98(3):1626-33
references: 17596425
references: Neuroimage. 2012 Apr 2;60(2):952-7
references: 22306799
references: Neuroimage. 2010 Apr 15;50(3):1148-67
references: 20056149
references: Front Hum Neurosci. 2014 Sep 09;8:686
references: 25249960
references: Neuroimage. 1999 Jul;10(1):63-83
references: 10385582
references: Cereb Cortex. 2001 May;11(5):463-73
references: 11313298
references: Cereb Cortex. 2015 Sep;25(9):3144-58
references: 24862848
references: Cereb Cortex. 2013 Nov;23(11):2734-53
references: 22918981
references: J Neurosci. 2007 May 16;27(20):5326-37
references: 17507555
references: Neuroreport. 2004 Oct 25;15(15):2407-10
references: 15640765
references: Neuroimage. 2009 Jul 1;46(3):844-53
references: 19285143
references: Hum Brain Mapp. 2009 Sep;30(9):2722-30
references: 19172650
references: J Cogn Neurosci. 2008 Sep;20(9):1611-23
references: 18345991
references: Nat Neurosci. 2010 Apr;13(4):417-8
references: 20208528
references: Cereb Cortex. 1996 Mar-Apr;6(2):226-37
references: 8670653
references: Curr Opin Neurobiol. 2009 Dec;19(6):666-71
references: 19880311
references: Eur J Neurosci. 2001 Jan;13(2):400-4
references: 11168545
references: Trends Cogn Sci. 2014 Apr;18(4):163-6
references: 24484764
references: J Neurosci. 2006 Sep 20;26(38):9736-42
references: 16988044
references: J Comp Neurol. 2000 Feb 28;418(1):1-21
references: 10701752
references: Nat Rev Neurosci. 2010 Apr;11(4):264-74
references: 20216547
references: J Cogn Neurosci. 2005 Feb;17(2):212-26
references: 15811234
references: Cereb Cortex. 2011 Sep;21(9):2113-21
references: 21330469
references: Curr Opin Neurobiol. 2014 Feb;24(1):39-46
references: 24492077
references: Hum Brain Mapp. 1997;5(4):222-7
references: 20408219
references: J Neurophysiol. 2005 Jan;93(1):603-8
references: 15295012
references: Curr Opin Neurobiol. 2001 Apr;11(2):157-63
references: 11301234
references: J Neurosci. 2011 Mar 9;31(10):3743-56
references: 21389229
references: Neuron. 2004 Apr 22;42(2):335-46
references: 15091347
references: Hum Brain Mapp. 2013 Aug;34(8):1882-95
references: 22422484
references: J Neurophysiol. 2010 Aug;104(2):1077-89
references: 20538772
references: Exp Brain Res. 2003 Nov;153(2):180-9
references: 12961051
references: Annu Rev Neurosci. 2004;27:169-92
references: 15217330
references: Cereb Cortex. 2008 Sep;18(9):2158-68
references: 18234687
references: Brain Struct Funct. 2014 Jan;219(1):119-40
references: 23283478
references: Hum Brain Mapp. 2011 Dec;32(12):2104-14
references: 21305659
references: Neuron. 2005 Aug 4;47(3):457-70
references: 16055068
references: Science. 2001 Sep 28;293(5539):2470-3
references: 11577239
references: Neuropsychologia. 2006;44(13):2668-84
references: 16337974
references: Cereb Cortex. 2006 Oct;16(10):1453-61
references: 16339084
references: Neuroimage. 2007 Oct 1;37(4):1315-28
references: 17689268
references: Curr Opin Neurobiol. 2006 Apr;16(2):205-12
references: 16563735
references: Eur J Neurosci. 2008 Oct;28(8):1569-88
references: 18691325
references: Nat Neurosci. 2008 Nov;11(11):1267-9
references: 18820694
references: J Neurosci. 2005 Nov 23;25(47):11055-9
references: 16306418
references: Brain. 1997 Jan;120 ( Pt 1):141-57
references: 9055804
references: Front Hum Neurosci. 2013 May 29;7:227
references: 23754999
references: Brain. 2005 Jul;128(Pt 7):1571-83
references: 15817510