TY - JOUR

T1 - Reciprocal or independent hemispheric specializations: Evidence from cerebral dominance for fluency, faces, and bodies in right- and left-handers

AU - Karlsson, Emma

AU - Johnstone, Leah

AU - Carey, David

N1 - NO EMBARGO upon publication © 2021, American Psychological Association. This paper is not the copy of record and may not exactly replicate the final, authoritative version of the article. Please do not copy or cite without authors' permission. The final article will be available, upon publication, via its DOI: 10.1037/pne0000269

PY - 2022/6

Y1 - 2022/6

N2 - Objective: There are distinct cortical regions that respond preferentially to human faces and bodies. It is generally accepted that these face- and body-selective regions are lateralized with a preference for the right hemisphere, but unknown how frequently these biases occur or if they are lateralized in a complementary fashion to language processing. Methods: fMRI was used to examine face and body lateralization in two samples of right-handers (n’s = 31 and 18) and left-handers (n’s = 43 and 24) with ‘typical’, left hemisphere, language dominance to examine the frequency of these biases. Crucially, we also recruited individuals with ‘atypical’, right hemisphere, language dominance (n’s = 17 and 10) to examine complementarity with language. Results: Language typical right-handers had consistent population-level and average right-sided biases for face- and body perception. Language typical left-handers had population-level biases for faces in sample 2, but not sample 1; and for bodies in sample 1 but not sample 2. Language typical left-handers were, on average, right-lateralized for faces in both samples, but right-lateralized for bodies in sample 1 only. Language atypicals did not have a population-level bias for body- or face perception, and were, on average, left-lateralized for faces in sample 1, but not in sample 2. Atypicals were not lateralized for body perception.Conclusions: These results add to the growing literature which suggests that many right hemisphere processes are not lateralized in a fully complementary fashion to language. Left-handers seem to have more varied lateralization patterns even when language dominance is controlled for.

AB - Objective: There are distinct cortical regions that respond preferentially to human faces and bodies. It is generally accepted that these face- and body-selective regions are lateralized with a preference for the right hemisphere, but unknown how frequently these biases occur or if they are lateralized in a complementary fashion to language processing. Methods: fMRI was used to examine face and body lateralization in two samples of right-handers (n’s = 31 and 18) and left-handers (n’s = 43 and 24) with ‘typical’, left hemisphere, language dominance to examine the frequency of these biases. Crucially, we also recruited individuals with ‘atypical’, right hemisphere, language dominance (n’s = 17 and 10) to examine complementarity with language. Results: Language typical right-handers had consistent population-level and average right-sided biases for face- and body perception. Language typical left-handers had population-level biases for faces in sample 2, but not sample 1; and for bodies in sample 1 but not sample 2. Language typical left-handers were, on average, right-lateralized for faces in both samples, but right-lateralized for bodies in sample 1 only. Language atypicals did not have a population-level bias for body- or face perception, and were, on average, left-lateralized for faces in sample 1, but not in sample 2. Atypicals were not lateralized for body perception.Conclusions: These results add to the growing literature which suggests that many right hemisphere processes are not lateralized in a fully complementary fashion to language. Left-handers seem to have more varied lateralization patterns even when language dominance is controlled for.

KW - Hemispheric lateralization

KW - functional brain asymmetry

KW - atypical language dominance

KW - Handedness

U2 - 10.1037/pne0000269

DO - 10.1037/pne0000269

M3 - Article

VL - 15

SP - 89

EP - 104

JO - Psychology & Neuroscience

JF - Psychology & Neuroscience

SN - 1983-3288

IS - 2

ER -