Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications

BackgroundFunctional MRI (fMRI) studies conducted on young adults reveal a predominantly left-lateralized cortical language network during semantic and phonological processing (SP and PP, respectively). Both linguistic dimensions have been advanced as potential cognitive markers of pathological agin...

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Main Authors: David Toloza-Ramirez, Rodrigo Santibañez, Leonardo Arraño-Carrasco, Romina Zunino-Pesce, Teresa Julio-Ramos, David A. Copland, Camilo Quezada, Carolina Mendez-Orellana
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-07-01
Series:Frontiers in Aging Neuroscience
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Online Access:https://www.frontiersin.org/articles/10.3389/fnagi.2025.1547162/full
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author David Toloza-Ramirez
David Toloza-Ramirez
Rodrigo Santibañez
Leonardo Arraño-Carrasco
Romina Zunino-Pesce
Teresa Julio-Ramos
David A. Copland
Camilo Quezada
Carolina Mendez-Orellana
Carolina Mendez-Orellana
Carolina Mendez-Orellana
author_facet David Toloza-Ramirez
David Toloza-Ramirez
Rodrigo Santibañez
Leonardo Arraño-Carrasco
Romina Zunino-Pesce
Teresa Julio-Ramos
David A. Copland
Camilo Quezada
Carolina Mendez-Orellana
Carolina Mendez-Orellana
Carolina Mendez-Orellana
author_sort David Toloza-Ramirez
collection DOAJ
description BackgroundFunctional MRI (fMRI) studies conducted on young adults reveal a predominantly left-lateralized cortical language network during semantic and phonological processing (SP and PP, respectively). Both linguistic dimensions have been advanced as potential cognitive markers of pathological aging. However, the neural mechanisms underlying SP and PP among healthy older adults remain poorly understood.AimThis study aimed to investigate the dynamics of language lateralization among native Spanish-speaking older adults in relation to their behavioral performance in specific semantic and phonological tasks.MethodologyTwenty-eight healthy, right-handed older Chilean adults (mean age: 67.7, SD±: 7.44, range: 60–87) took part in an fMRI session during which they performed semantic and phonological tasks. They were also evaluated for overall language performance using the Spanish version of ScreeLing and verbal fluency tasks. A fixed-effect analysis was performed to explore group-level differences. Standard regression analyses were also used to assess the association between brain activation and language performance.ResultsBoth SP and PP elicited bilateral activation in the pars triangularis and opercularis of the inferior frontal gyrus (IFG) and the superior temporal gyrus. Activation was also observed in the left inferior parietal gyrus. Semantic fluency performance was significantly associated with activation in the right angular gyrus and the pars opercularis of the IFG. In contrast, phonological fluency was associated with bilateral activation in the IFG pars orbitalis.ConclusionAmong healthy older adults, SP and PP recruit bilateral language-related brain regions, potentially reflecting compensatory mechanisms associated with normal aging. Notably, the IFG pars orbitalis may play a distinct role in supporting phonological fluency, despite not being a region traditionally linked to PP. Further research is needed to clarify the contribution of this region to phonological performance among aging adults.
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spelling doaj-art-b20b8f9d353d4e01a86c0d7720d324f42025-08-20T03:55:59ZengFrontiers Media S.A.Frontiers in Aging Neuroscience1663-43652025-07-011710.3389/fnagi.2025.15471621547162Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implicationsDavid Toloza-Ramirez0David Toloza-Ramirez1Rodrigo Santibañez2Leonardo Arraño-Carrasco3Romina Zunino-Pesce4Teresa Julio-Ramos5David A. Copland6Camilo Quezada7Carolina Mendez-Orellana8Carolina Mendez-Orellana9Carolina Mendez-Orellana10Interdisciplinary Center for Neuroscience, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, ChileFaculty of Rehabilitation Sciences, School of Speech Therapy, Exercise and Rehabilitation Sciences Institute, Universidad Andres Bello, Santiago, ChileDepartment of Neurology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, ChileDepartment of Radiology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, ChileDepartment of Radiology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, ChilePhD Program in Health Sciences and Engineering, Universidad de Valparaiso, Valparaiso, ChileQueensland Aphasia Research Centre, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, QLD, AustraliaDepartamento de Fonoaudiología, Facultad de Medicina, Universidad de Chile, Santiago, ChileFaculty of Medicine, Health Sciences School, Pontificia Universidad Católica de Chile, Santiago, ChileDepartment of Neurosurgery, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile0Department of Radiology and Nuclear Medicine, Erasmus MC – University Medical Center Rotterdam, Rotterdam, NetherlandsBackgroundFunctional MRI (fMRI) studies conducted on young adults reveal a predominantly left-lateralized cortical language network during semantic and phonological processing (SP and PP, respectively). Both linguistic dimensions have been advanced as potential cognitive markers of pathological aging. However, the neural mechanisms underlying SP and PP among healthy older adults remain poorly understood.AimThis study aimed to investigate the dynamics of language lateralization among native Spanish-speaking older adults in relation to their behavioral performance in specific semantic and phonological tasks.MethodologyTwenty-eight healthy, right-handed older Chilean adults (mean age: 67.7, SD±: 7.44, range: 60–87) took part in an fMRI session during which they performed semantic and phonological tasks. They were also evaluated for overall language performance using the Spanish version of ScreeLing and verbal fluency tasks. A fixed-effect analysis was performed to explore group-level differences. Standard regression analyses were also used to assess the association between brain activation and language performance.ResultsBoth SP and PP elicited bilateral activation in the pars triangularis and opercularis of the inferior frontal gyrus (IFG) and the superior temporal gyrus. Activation was also observed in the left inferior parietal gyrus. Semantic fluency performance was significantly associated with activation in the right angular gyrus and the pars opercularis of the IFG. In contrast, phonological fluency was associated with bilateral activation in the IFG pars orbitalis.ConclusionAmong healthy older adults, SP and PP recruit bilateral language-related brain regions, potentially reflecting compensatory mechanisms associated with normal aging. Notably, the IFG pars orbitalis may play a distinct role in supporting phonological fluency, despite not being a region traditionally linked to PP. Further research is needed to clarify the contribution of this region to phonological performance among aging adults.https://www.frontiersin.org/articles/10.3389/fnagi.2025.1547162/fullagingsemanticsphonologyneural basisfunctional MRI
spellingShingle David Toloza-Ramirez
David Toloza-Ramirez
Rodrigo Santibañez
Leonardo Arraño-Carrasco
Romina Zunino-Pesce
Teresa Julio-Ramos
David A. Copland
Camilo Quezada
Carolina Mendez-Orellana
Carolina Mendez-Orellana
Carolina Mendez-Orellana
Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
Frontiers in Aging Neuroscience
aging
semantics
phonology
neural basis
functional MRI
title Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
title_full Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
title_fullStr Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
title_full_unstemmed Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
title_short Beyond the left cerebral hemisphere: bilateral language lateralization in healthy aging and its clinical implications
title_sort beyond the left cerebral hemisphere bilateral language lateralization in healthy aging and its clinical implications
topic aging
semantics
phonology
neural basis
functional MRI
url https://www.frontiersin.org/articles/10.3389/fnagi.2025.1547162/full
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