Evidence map›Paper›PMID 41043000›Full record

ArticleThe journals of gerontology. Series B, Psychological sciences and social sciences2026

Cognitive dedifferentiation in later life: longitudinal findings from the Lothian Birth Cohort 1936.

Joanna E Moodie, Janie Corley, Ian J Deary, Simon R Cox

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Article in The journals of gerontology. Series B, Psychological sciences and social sciences, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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1citing papers in PubMed
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1 · What the graph read from it

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Joanna E MoodieLothian Birth Cohorts, Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0003-0404-6295
Janie CorleyLothian Birth Cohorts, Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0002-7551-1871
Ian J DearyLothian Birth Cohorts, Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0002-1733-263X
Simon R CoxLothian Birth Cohorts, Department of Psychology, The University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0003-4036-3642

Funding

BBSRC & ESRC BB/W008793/1Medical Research Council MR/K026992/1Medical Research Council MR/M01311/1
6 · The paper itself

Abstract

objectivesIn the cognitive aging literature, the dedifferentiation hypothesis refers to cognitive skills becoming more interrelated in older adulthood. Here, we report evidence for cognitive dedifferentiation in the Lothian Birth Cohort 1936 (LBC1936).

methodsThe LBC1936 is a narrow-age cohort assessed at 5 waves between ages 70 and 82. We analyzed data from 418 participants (49% male) who provided cognitive data at all 5 waves.

resultsIn single-order structural equation models, the percentage of variance that general cognitive functioning (g) accounted for across 13 cognitive tests increases by wave; w1 to w5: 25%, 27%, 29%, 31%, 36%, and the group-level rate of dedifferentiation closely tracked the group-level rate of cognitive decline (r  =  -.991, p = .001). A hierarchical model, which included 4 cognitive domains as mid-level factors, provides evidence of cognitive dedifferentiation at the cognitive domain level: fluid cognitive domains (Visuospatial Skills, Processing Speed, and Verbal Memory) converged, and Crystallised Ability became less influential on the structure of g over time. We also show that this group-level measure of dedifferentiation reflects the individual-level measure of dispersion (people tend to score more similarly across different cognitive tests with advancing age), r  =  -.989, p = .001. DISCUSSION: The current results have implications for longitudinal g modeling choices: it cannot be assumed that g's composition is the same over time. Future longitudinal research will be important in clarifying the incremental validity, determinants, mechanisms, and implications of cognitive differentiation and dedifferentiation across the lifespan.

Indexed as

CognitionCognitive AgingCognitive DysfunctionAgedAged, 80 and overFemaleHumansLongitudinal StudiesMaleNeuropsychological TestsScotlandCognitive agingDispersionGeneral cognitive functioningLongitudinal cohort

Identifiers

PMID41043000
PMCPMC12779353

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