Older adults preserve audiovisual integration through enhanced cortical activations, not by recruiting new regions

Jones, SA ORCID: https://orcid.org/0000-0002-1767-9414 and Noppeney, U, 2024. Older adults preserve audiovisual integration through enhanced cortical activations, not by recruiting new regions. PLOS Biology, 22 (2): e3002494. ISSN 1544-9173

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Abstract

Effective interactions with the environment rely on the integration of multisensory signals: Our brains must efficiently combine signals that share a common source, and segregate those that do not. Healthy ageing can change or impair this process. This functional magnetic resonance imaging study assessed the neural mechanisms underlying age differences in the integration of auditory and visual spatial cues. Participants were presented with synchronous audiovisual signals at various degrees of spatial disparity and indicated their perceived sound location. Behaviourally, older adults were able to maintain localisation accuracy. At the neural level, they integrated auditory and visual cues into spatial representations along dorsal auditory and visual processing pathways similarly to their younger counterparts but showed greater activations in a widespread system of frontal, temporal, and parietal areas. According to multivariate Bayesian decoding, these areas encoded critical stimulus information beyond that which was encoded in the brain areas commonly activated by both groups. Surprisingly, however, the boost in information provided by these areas with age-related activation increases was comparable across the 2 age groups. This dissociation—between comparable information encoded in brain activation patterns across the 2 age groups, but age-related increases in regional blood-oxygen-level-dependent responses—contradicts the widespread notion that older adults recruit new regions as a compensatory mechanism to encode task-relevant information. Instead, our findings suggest that activation increases in older adults reflect nonspecific or modulatory mechanisms related to less efficient or slower processing, or greater demands on attentional resources.

Item Type:	Journal article
Publication Title:	PLOS Biology
Creators:	Jones, S.A. and Noppeney, U.
Publisher:	Public Library of Science (PLoS)
Date:	6 February 2024
Volume:	22
Number:	2
ISSN:	1544-9173
Identifiers:	Number Type 10.1371/journal.pbio.3002494 DOI 1862560 Other
Divisions:	Schools > School of Social Sciences
Record created by:	Laura Ward
Date Added:	19 Feb 2024 16:21
Last Modified:	19 Feb 2024 16:21
URI:	https://irep.ntu.ac.uk/id/eprint/50887

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