高齢になっても健康でいることは、適切な言葉を見つけるのに役立つ脳領域をサポートする(Being fit in older age supports brain regions that help you reach for right words)

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2025-08-28 バーミンガム大学

バーミンガム大学の研究で、高齢期の体力と「言葉が出てこない現象(喉元現象)」との関連が明らかになった。60~81歳の健康な成人73名を対象に、心肺持久力(VO₂ピーク)を測定し、MRI下で言語課題を行ったところ、体力が高い人ほど言葉を探す際の脳活動が特徴的で、言葉が出てこない頻度が少ないことが確認された。具体的には、有酸素能力が高い参加者は言語ネットワークにおける神経活動が異なり、語彙検索においてより効率的に脳を働かせていた。研究者は、運動習慣が脳の言語処理機能を支え、加齢による言葉探しの困難を軽減する可能性を示すものだと強調している。本成果は、健康な加齢において身体活動が認知機能維持に果たす役割を裏付けるものであり、高齢者の生活の質向上に資する新たなエビデンスとなった。

<関連情報>

高齢者の舌先体験を説明する:脳と心肺機能の要因の役割 Explaining tip-of-the-tongue experiences in older adults: The role of brain-based and cardiorespiratory fitness factors

Foyzul Rahman, Kamen A. Tsvetanov, Jack Feron, Karen Mullinger, Kelsey Joyce, Ahmed Gilani, Eunice G. Fernandes, Allison Wetterlin, Linda Wheeldon, Samuel J.E. Lucas, Katrien Segaert
Neurobiology of Aging  Available online: 25 June 2025
DOI:https://doi.org/10.1016/j.neurobiolaging.2025.06.008

Fig 2

Highlights

  • Word-finding problems are linked to brain health and cardiorespiratory fitness(CRF).
  • Brain activity linked to word-finding failures is modulated by CRF and age.
  • Distinct contribution of structure and perfusion also associated with word-finding.
  • Linking brain and CRF factors provides better account of age-related cognitive decline.

Abstract

Cognitive decline associated with healthy ageing is multifactorial: brain-based and lifestyle factors uniquely and jointly contribute to distinct neurocognitive trajectories of ageing. To evaluate existing models of neurocognitive ageing such as compensation, maintenance, or reserve, we explore how various known brain-based and cardiorespiratory fitness factors intersect to better understand cognitive decline. In a pre-registered study (https://osf.io/6fqg7), we tested 73 healthy older adults aged 60—81 (M = 65.51, SD = 4.94) and collected neuroimaging (functional, structural, and perfusion MRI), cardiorespiratory fitness, and cognitive data to investigate a prominent challenge for older adults: word-finding failures. fMRI signal was recorded while participants responded to a definition-based tip-of-the-tongue task, T1-weighted imaging estimated grey matter volume, and cerebral blood flow was indexed using multi-delay pseudo-continuous arterial spin labelling. Commonality analyses were used to analyse these multi-domain data (neuroimaging, cardiorespiratory fitness, language skills, demographic characteristics) and uncover associations between predictors in explaining age-related tip-of-the-tongue rates. Commonality analyses revealed that functional activation of language networks associated with tip-of-the-tongue states is in part linked with age and, interestingly, cardiorespiratory fitness: the combination of higher cardiorespiratory fitness and functional recruitment in some older adults offsets part of the age-related variance in tip-of-the-tongues. Moreover, age-associated atrophy and perfusion in regions other than those showing functional differences accounted for variance in tip-of-the-tongues. Our findings can be interpreted in the context of the classic models of neurocognitive ageing, suggesting compensation. Brain health indices in concordance with cardiorespiratory fitness can provide a more holistic explanation of individual differences in age-related cognitive decline.

医療・健康
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