title: New human-specific brain landmark: the depth asymmetry of superior temporal sulcus.
abstract: Identifying potentially unique features of the human cerebral cortex is a first step to understanding how evolution has shaped the brain in our species. By analyzing MR images obtained from 177 humans and 73 chimpanzees, we observed a human-specific asymmetry in the superior temporal sulcus at the heart of the communication regions and which we have named the "superior temporal asymmetrical pit" (STAP). This 45-mm-long segment ventral to Heschl's gyrus is deeper in the right hemisphere than in the left in 95% of typical human subjects, from infanthood till adulthood, and is present, irrespective of handedness, language lateralization, and sex although it is greater in males than in females. The STAP also is seen in several groups of atypical subjects including persons with situs inversus, autistic spectrum disorder, Turner syndrome, and corpus callosum agenesis. It is explained in part by the larger number of sulcal interruptions in the left than in the right hemisphere. Its early presence in the infants of this study as well as in fetuses and premature infants suggests a strong genetic influence. Because this asymmetry is barely visible in chimpanzees, we recommend the STAP region during midgestation as an important phenotype to investigate asymmetrical variations of gene expression among the primate lineage. This genetic target may provide important insights regarding the evolution of the crucial cognitive abilities sustained by this sulcus in our species, namely communication and social cognition.
authors.affiliation: Cognitive Neuroimaging Unit, U992, francois.leroy@cea.fr.
authors.forename: François
authors.initials: F
authors.lastname: Leroy
authors.affiliation: Shanghai Key Laboratory of Brain Functional Genomics, East China Normal University, Shanghai 200241, China;
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322;
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Bogart
authors.affiliation: Cognitive Neuroimaging Unit, U992.
authors.forename: Jessica
authors.initials: J
authors.lastname: Dubois
authors.affiliation: Laboratory for Systems and Information Science, UMR CNRS 7296, Aix-Marseille University, Marseille 13284, France;
authors.forename: Olivier
authors.initials: O
authors.lastname: Coulon
authors.affiliation: Cognitive Neuroimaging Unit, U992.
authors.forename: Karla
authors.initials: K
authors.lastname: Monzalvo
authors.affiliation: Analysis and Processing of Information Unit.
authors.forename: Clara
authors.initials: C
authors.lastname: Fischer
authors.affiliation: Cognitive Neuroimaging Unit, U992.
authors.forename: Hervé
authors.initials: H
authors.lastname: Glasel
authors.affiliation: Department of Experimental Psychology, Ghent University, Ghent B-9000, Belgium;
authors.forename: Lise
authors.initials: L
authors.lastname: Van der Haegen
authors.affiliation: Cognitive Neuroimaging Unit, U992.
authors.forename: Audrey
authors.initials: A
authors.lastname: Bénézit
authors.affiliation: Institute of Neuroscience, National Yang-Ming University, Taipei City 112, Taiwan;
authors.forename: Ching-Po
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Center for Morphometric Analysis, Neuroscience Center, Massachusetts General Hospital, Boston, MA 02114;
authors.forename: David N
authors.initials: DN
authors.lastname: Kennedy
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka 565-0871 Japan;
authors.forename: Aya S
authors.initials: AS
authors.lastname: Ihara
authors.affiliation: Clinical and Translational Applications Research Unit, U663, and.
authors.forename: Lucie
authors.initials: L
authors.lastname: Hertz-Pannier
authors.affiliation: Neuropediatrics Department, Trousseau Hospital, Assistance Publique Hôpitaux de Paris, Paris 75012, France; and.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Moutard
authors.affiliation: Nuclear Magnetic Resonance Imaging and Spectroscopy Unit, Office of Atomic Energy and Alternative Energies (CEA), INSERM, NeuroSpin, Gif-sur-Yvette 91191, France;
authors.forename: Cyril
authors.initials: C
authors.lastname: Poupon
authors.affiliation: Analysis and Processing of Information Unit.
authors.forename: Marc
authors.initials: M
authors.lastname: Brysbaert
authors.affiliation: Clinical Research Imaging Centre, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh EH8 9YL, United Kingdom.
authors.forename: Neil
authors.initials: N
authors.lastname: Roberts
authors.affiliation: Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322;
authors.forename: William D
authors.initials: WD
authors.lastname: Hopkins
authors.affiliation: Analysis and Processing of Information Unit.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mangin
authors.affiliation: Cognitive Neuroimaging Unit, U992.
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Dehaene-Lambertz
mesh_terms: D000328:Adult; D061085:Agenesis of Corpus Callosum / Q000000981:diagnostic imaging / Q000503:physiopathology; D000818:Animals; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000000981:diagnostic imaging / Q000503:physiopathology; D003071:Cognition; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D002679:Pan troglodytes; D011859:Radiography; D012857:Situs Inversus / Q000000981:diagnostic imaging / Q000503:physiopathology; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology; D014424:Turner Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology
keywords: STS; anatomy; asymmetry; brain; human-specific