Agarwal, S;
Stamatakis, EA;
Geva, S;
Warburton, EA;
(2016)
Dominant hemisphere functional networks compensate for structural connectivity loss to preserve phonological retrieval with aging.
Brain and Behavior
, 6
(9)
, Article e00495. 10.1002/brb3.495.
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Abstract
Introduction Loss of hemispheric asymmetry during cognitive tasks has been previously demonstrated in the literature. In the context of language, increased right hemisphere activation is observed with aging. Whether this relates to compensation to preserve cognitive function or dedifferentiation implying loss of hemispheric specificity without functional consequence, remains unclear. Methods With a multifaceted approach, integrating structural and functional imaging data during a word retrieval task, in a group of younger and older adults with equivalent cognitive performance, we aimed to establish whether interactions between hemispheres or reorganization of dominant hemisphere networks preserve function. We examined functional and structural connectivity on data from our previously published functional activation study. Functional connectivity was measured using psychophysiological interactions analysis from the left inferior frontal gyrus (LIFG) and the left insula (LINS), based on published literature, and the right inferior frontal gyrus (RIFG) based on our previous study. Results Although RIFG showed increased activation, its connectivity decreased with age. Meanwhile, LIFG and LINS connected more bilaterally in the older adults. White matter integrity, measured by fractional anisotropy (FA) from diffusion tensor imaging, decreased significantly in the older group. Importantly, LINS functional connectivity to LIFG correlated inversely with FA. Conclusions We demonstrate that left hemispheric language areas show higher functional connectivity in older adults with intact behavioral performance, and thus, may have a role in preserving function. The inverse correlation of functional and structural connectivity with age is in keeping with emerging literature and merits further investigation with tractography studies and in other cognitive domains.
| Type: | Article |
|---|---|
| Title: | Dominant hemisphere functional networks compensate for structural connectivity loss to preserve phonological retrieval with aging |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1002/brb3.495 |
| Publisher version: | http://doi.org/10.1002/brb3.495 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Science & Technology, Life Sciences & Biomedicine, Behavioral Sciences, Neurosciences, Neurosciences & Neurology, Aging, DTI, functional connectivity, language, phonology, PPI, word retrieval, PERISYLVIAN LANGUAGE NETWORKS, AGE-RELATED DIFFERENCES, TRAUMATIC BRAIN-INJURY, ADULT LIFE-SPAN, OF-THE-TONGUE, OLDER-ADULTS, WORD RETRIEVAL, CALLOSAL STRUCTURE, COGNITIVE DECLINE, DIFFUSION TENSOR |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Imaging Neuroscience |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1568246 |
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