title: Category-specific versus category-general semantic impairment induced by transcranial magnetic stimulation.
abstract: Semantic cognition permits us to bring meaning to our verbal and nonverbal experiences and to generate context- and time-appropriate behavior. It is core to language and nonverbal skilled behaviors and, when impaired after brain damage, it generates significant disability. A fundamental neuroscience question is, therefore, how does the brain code and generate semantic cognition? Historical and some contemporary theories emphasize that conceptualization stems from the joint action of modality-specific association cortices (the "distributed" theory) reflecting our accumulated verbal, motor, and sensory experiences. Parallel studies of semantic dementia, rTMS in normal participants, and neuroimaging indicate that the anterior temporal lobe (ATL) plays a crucial and necessary role in conceptualization by merging experience into an amodal semantic representation. Some contemporary computational models suggest that concepts reflect a hub-and-spoke combination of information--modality-specific association areas support sensory, verbal, and motor sources (the spokes) while anterior temporal lobes act as an amodal hub. We demonstrate novel and striking evidence in favor of this hypothesis by applying rTMS to normal participants: ATL stimulation generates a category-general impairment whereas IPL stimulation induces a category-specific deficit for man-made objects, reflecting the coding of praxis in this neural region.
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Manchester M13 9PL, UK. gorana.pobric@manchester.ac.uk
authors.forename: Gorana
authors.initials: G
authors.lastname: Pobric
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Jefferies
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Lambon Ralph
mesh_terms: D003071:Cognition / Q000502:physiology*; D003210:Concept Formation; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000503:physiopathology*; D006801:Humans; D007802:Language; D008297:Male; D008568:Memory / Q000502:physiology; D012660:Semantics; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects*; D055815:Young Adult
references.citation: Annu Rev Psychol. 2007;58:25-45
references.pmid: 16968210
references.citation: Psychon Bull Rev. 1994 Dec;1(4):476-90
references.pmid: 24203555
references.citation: Q J Exp Psychol. 1975 Nov;27(4):635-57
references.pmid: 1197619
references.citation: Cereb Cortex. 2009 Apr;19(4):832-8
references.pmid: 18678765
references.citation: Proc Natl Acad Sci U S A. 2010 Feb 9;107(6):2717-22
references.pmid: 20133780
references.citation: Cereb Cortex. 2009 Dec;19(12):2767-96
references.pmid: 19329570
references.citation: J Cogn Neurosci. 2003 Jan 1;15(1):30-46
references.pmid: 12590841
references.citation: Ann N Y Acad Sci. 2008 Mar;1124:61-76
references.pmid: 18400924
references.citation: Annu Rev Psychol. 2009;60:27-51
references.pmid: 18767921
references.citation: Brain. 2007 Apr;130(Pt 4):1138-47
references.pmid: 17251241
references.citation: Brain Lang. 2002 Aug;82(2):179-99
references.pmid: 12096875
references.citation: J Exp Psychol Gen. 1991 Dec;120(4):339-57
references.pmid: 1837294
references.citation: Neuropsychologia. 2000;38(9):1207-15
references.pmid: 10865096
references.citation: Behav Res Methods. 2007 Nov;39(4):973-8
references.pmid: 18183914
references.citation: Brain. 2007 Apr;130(Pt 4):1127-37
references.pmid: 17438021
references.citation: Brain. 1992 Dec;115 ( Pt 6):1783-806
references.pmid: 1486461
references.citation: Proc Natl Acad Sci U S A. 2007 Dec 11;104(50):20137-41
references.pmid: 18056637
references.citation: Cereb Cortex. 2010 Nov;20(11):2728-38
references.pmid: 20190005
references.citation: J Cogn Neurosci. 2010 Jun;22(6):1083-94
references.pmid: 19583477
references.citation: Nat Rev Neurosci. 2007 Dec;8(12):976-87
references.pmid: 18026167
references.citation: Brain. 1984 Sep;107 ( Pt 3):829-54
references.pmid: 6206910
references.citation: Nat Rev Neurosci. 2003 Apr;4(4):310-22
references.pmid: 12671647
references.citation: Cereb Cortex. 2006 Mar;16(3):437-45
references.pmid: 15944370