Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed

Abstract

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>OBJECTIVES</jats:title> <jats:p>To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether 1) these domains show different associations with age and education, 2) these domains show similar patterns of age-related change over time, and 3) education moderates the rate of decline in these domains.</jats:p> </jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education.</jats:p> </jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Two language domains, i.e., semantic control and semantic memory efficiency, and two cognitive domains, i.e., working memory and cognitive speed, were identified. Older age negatively affected all domains, but semantic memory efficiency and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain.</jats:p> </jats:sec> <jats:sec> <jats:title>DISCUSSION</jats:title> <jats:p>Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.</jats:p> </jats:sec>

Potential Diffusion Tensor Imaging Biomarkers for Elucidating Intra-Individual Age-Related Changes in Cognitive Control and Processing Speed

“…The discrepant findings among these studies are likely due to their differences in the length of the follow-up interval. The follow-up interval between the two timepoints in Vonk et al’s (2020) research was 4∼8 years, whereas in the other two research (i.e., Charlton et al, 2010 ; Lövdén et al, 2014 ), the age interval was about 2 years which is similar to the current study. Therefore, future studies with a longer follow-up interval or more times of follow-up are warranted.…”

“…First, in the current study, only a period of 1–2 years follow-up interval was performed, it is likely that the period is too short to be sensitive enough to reveal the aging process. For example, in the literature, Charlton et al (2010) and Lövdén et al (2014) using a follow-up approach likewise did not find an aging effect on cognitive changes, but Vonk et al (2020) found a linear aging effect in working memory and cognitive speed. The discrepant findings among these studies are likely due to their differences in the length of the follow-up interval.…”

Cross-sectional associations of amyloid burden with semantic cognition in older adults without dementia: A systematic review and meta-analysis

“…Differences in the magnitude of effect sizes across picture naming, semantic fluency, vocabulary, and WAIS Information may be caused for various reasons. Semantic cognition has multiple components, including semantic control, semantic memory efficiency, and semantic representation ( Jefferies, 2013 ; Vonk et al, 2020 ; Whitney et al, 2011 ). Different semantic tasks may tap into these components with different weights, which may make the tasks differentially sensitive to early cognitive symptoms in the course of Alzheimer’s disease.…”

“…Additionally, a large body of research has demonstrated the role of subtle semantic decline in early stages of the disease or in individuals at high risk for Alzheimer’s disease (e.g., Chertkow et al, 2008 ; Papp et al, 2016 ; Vonk et al, 2019a ). While a decline in episodic memory is not only present in Alzheimer’s disease but to a lesser extent also in normal aging, several aspects of semantic cognition stay relatively intact with normal aging ( Horn and Cattell, 1966 , 1967 ; Park et al, 2002 ; Salthouse, 2010 ; Vonk et al, 2020 ). Therefore, semantic cognition could play an important diagnostic and prognostic role in preclinical Alzheimer’s disease ( Venneri et al, 2018 ).…”

Investigating cognition in midlife

“…Although the effects of aging on physiological cognition are extensively studied, 56–58 the assessment of cognitive aging in midlife using simple tests suitable for use in a clinical setting, remains poorly investigated 59–62 . We here show that cognitive functions all undergo measurable, significant, and progressive deterioration during midlife aging with psychomotor speed most vulnerable to the effects of aging.…”