title: Hemispheric specialization in affective responses, cerebral dominance for language, and handedness: Lateralization of emotion, language, and dexterity.
abstract: Hemispheric specialization in affective responses has received little attention in the literature. This is a fundamental variable to understand circuit dynamics of networks subserving emotion. In this study we put to test a modified "valence" hypothesis of emotion processing, considering that sadness and happiness are processed by each hemisphere in relation to dominance for language and handedness. Mood induction and language activation during functional magnetic resonance imaging (fMRI) were used in 20 right-handed and 20 nonright-handed subjects, focusing on interconnected regions known to play critical roles in affective responses: subgenual cingulate cortex, amygdala, and anterior insular cortex. We observed a consistent relationship between lateralization of affective processing, motor dexterity, and language in individuals with clear right-handedness. Sadness induces a greater activation of right-hemisphere cortical structures in right-handed, left-dominant individuals, which is not evident in nonright-handed subjects who show no consistent hemispheric dominance for language. In anterior insula, right-handed individuals displayed reciprocal activation of either hemisphere depending upon mood valence, whereas amygdala activation was predominantly left-sided regardless of mood valence. Nonright-handed individuals exhibited less consistent brain lateralization of affective processing regardless of language and motor dexterity lateralization. In contrast with traditional views on emotion processing lateralization, hemispheric specialization in affective responses is not a unitary process but is specific to the brain structure being activated.
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina; Department of Neurophysiology, University of Buenos Aires School of Psychology, Buenos Aires, Argentina.
authors.forename: Elsa Yolanda
authors.initials: EY
authors.lastname: Costanzo
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Argentine National Council of Scientific and Technological Research (CONICET), Argentina; Department of Physics, University of Buenos Aires School of Science, Buenos Aires, Argentina.
authors.forename: Mirta
authors.initials: M
authors.lastname: Villarreal
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina; Argentine National Council of Scientific and Technological Research (CONICET), Argentina.
authors.forename: Lucas Javier
authors.initials: LJ
authors.lastname: Drucaroff
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ortiz-Villafañe
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina; Argentine National Council of Scientific and Technological Research (CONICET), Argentina; Department of Neurophysiology, University of Buenos Aires School of Psychology, Buenos Aires, Argentina.
authors.forename: Mariana Nair
authors.initials: MN
authors.lastname: Castro
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Micaela
authors.initials: M
authors.lastname: Goldschmidt
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Agustina Edith
authors.initials: AE
authors.lastname: Wainsztein
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina; Argentine National Council of Scientific and Technological Research (CONICET), Argentina.
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Ladrón-de-Guevara
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Romero
authors.affiliation: Argentine National Council of Scientific and Technological Research (CONICET), Argentina; Center for Neuropsychiatry and Behavioral Neurology (CENECON), Hospital de Clínicas "José de San Martín", Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Luis Ignacio
authors.initials: LI
authors.lastname: Brusco
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
authors.forename: Joan A
authors.initials: JA
authors.lastname: Camprodon
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States.
authors.forename: Charles
authors.initials: C
authors.lastname: Nemeroff
authors.affiliation: FLENI Psychiatry and Neuroimaging, Buenos Aires, Argentina; Department of Mental Health (FLENI Teaching Unit), University of Buenos Aires School of Medicine, Buenos Aires, Argentina; Argentine National Council of Scientific and Technological Research (CONICET), Argentina; Department of Neurophysiology, University of Buenos Aires School of Psychology, Buenos Aires, Argentina. Electronic address: sguinjoan@fleni.org.ar.
authors.forename: Salvador Martín
authors.initials: SM
authors.lastname: Guinjoan
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004644:Emotions / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology
keywords: Amygdala; Anterior insula; Emotion; Lateralization; Subgenual cingulate; fMRI