Structural brain aging and speech production: a surface-based brain morphometry study.
While there has been a growing number of studies examining the neurofunctional correlates of speech production over the past decade, the neurostructural correlates of this immensely important human behaviour remain less well understood, despite the fact that previous studies have established links between brain structure and behaviour, including speech and language. In the present study, we thus examined, for the first time, the relationship between surface-based cortical thickness (CT) and three different behavioural indexes of sublexical speech production: response duration, reaction times and articulatory accuracy, in healthy young and older adults during the production of simple and complex meaningless sequences of syllables (e.g., /pa-pa-pa/ vs. /pa-ta-ka/). The results show that each behavioural speech measure was sensitive to the complexity of the sequences, as indicated by slower reaction times, longer response durations and decreased articulatory accuracy in both groups for the complex sequences. Older adults produced longer speech responses, particularly during the production of complex sequence. Unique age-independent and age-dependent relationships between brain structure and each of these behavioural measures were found in several cortical and subcortical regions known for their involvement in speech production, including the bilateral anterior insula, the left primary motor area, the rostral supramarginal gyrus, the right inferior frontal sulcus, the bilateral putamen and caudate, and in some region less typically associated with speech production, such as the posterior cingulate cortex.
Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC, Canada. Pascale.tremblay@fmed.ulaval.ca.|Département de Réadaptation, Faculté de Médecine, Université Laval, Quebec, QC, Canada. Pascale.tremblay@fmed.ulaval.ca.|Département de Rehabilitation, Université Laval, Office 4462, 1050 avenue de la Médecine, Quebec, QC, G1V 0A6, Canada. Pascale.tremblay@fmed.ulaval.ca.
Pascale
P
Tremblay
Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec, QC, Canada.|Département de Réadaptation, Faculté de Médecine, Université Laval, Quebec, QC, Canada.
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Deschamps
D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000375:Aging; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D066128:Gray Matter / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D013060:Speech / Q000502:physiology*; D013068:Speech Production Measurement; D055815:Young Adult
Aging; Anterior insula; Cortical thickness; Speech production; Subcortical volume