cognition across lifespan

Emily S. Nichols, Conor J. Wild, Adrian M. Owen, Andrea Soddu
Citation: Nichols, E.S.; Wild, C.J.; Owen, A.M.; Soddu, A. (2021). Cognition across the Lifespan: Investigating Age, Sex, and Other Sociodemographic Influences. Behavioral Sciences, 11(4), 51. DOI: https://doi.org/10.3390/bs11040051

Focus of study: Understanding cognitive health maintenance across the lifespan, driven by a significant multi-billion-dollar industry.
Importance: Clear understanding of cognitive domains' development and decline across sexes and life stages necessary for interventions.
Psychiatric illnesses (e.g., anxiety, depression, substance use) are known to impact cognition and exhibit sex differences.
Aim: Assess cognitive function differences between men and women within a sample of 18,902 participants (age 12-69).
Methodology: Utilized online cognitive testing. Sample included 9451 men and 9451 women matched on socio-demographic factors.
Conclusions: Minimal sex differences in cognitive function were observed, suggesting significant influence from environmental factors. Cognitive differences across lifespan are a product of intricate biological-environmental interplay.

Societal Context: In 2020, 22% of the world population was over age 65 (approx. 1.7 billion).
Cognitive health is increasingly focal due to the aging population.
Objective: Establish clear measures of cognitive changes in gendered populations, critical for tailoring cognitive aging interventions.
Developmental Trajectory of Cognition:
- Rapid development during childhood.
- Executive function generally matures by age 18, but some aspects grow through early adulthood.
- Peak cognitive abilities typically in young adulthood; yet variability exists across functions.
- Mid to late adulthood shows a gradual cognitive decline, perceived as part of healthy aging.
Gender Dynamics:
- Existing disparities in cognitive abilities are influenced by socio-cultural factors rather than being strictly biological.
- Issues such as anxiety and depression present differently across genders, affecting cognition.
Environment and Cognition: A multitude of socio-demographic factors (e.g., SES impact cognitive performance).

Source: Cambridge Brain Sciences online platform.
Sample Size: 65,994 participants (out of 76,452) completed a 12-task cognitive test.
Final Analysis: 45,779 participants after demographic matching; 9451 men and 9451 women retained after filtering for outliers and restricting age range (12-69).
Demographics summarized in Table 1, with relevant statistics and measures provided.

Participants completed a fixed order of 12 cognitive tests measuring various cognitive functions (described succinctly in supplementary materials). The battery assessed:
- Inhibition
- Executive function
- Selective attention
- Reasoning
- Verbal short-term memory
- Spatial working memory
- Planning
- Cognitive flexibility
Composite scores created for working memory, verbal abilities, and reasoning subsequent to empirical factor analysis.

Process: Participants navigate the Cambridge Brain Sciences online platform to consent, complete tasks, and respond to questionnaires, taking approximately 35 to 40 minutes.

Data analyzed using R and relevant packages to compute segmented regression models for cognitive performance based on age and sex, validating the segmentation through Davies’ test.

Women peaked in WM at age 20.42 (score = 0.046), with age positively associated with performance until that age then negatively afterward.
Men peaked slightly earlier at age 19.65 (score = 0.259). Significant differences identified between men's and women's peak scores.

Women showed a two-breakpoint model with the highest point at age 24.89. Significant coefficients indicate reliable increases and decreases around breakpoints, with men having a slightly later peak age (28.42). Both genders showed similar patterns of increase and decline.

Women exhibited an initial score high at age 12 (score = 0.223), transitioning into decline earlier at age 38.12. Men’s reasoning peaked later at age 19.62 with subsequent decline.
Notable finding: women began significant declines earlier than men, signaling different cognitive aging trajectories across sexes.

Women and men demonstrated distinct differences in demographic metrics affecting cognitive analysis.

Confirmed that cognitive domains' development and decline pattern is non-linear and domain-specific. The study highlights the need for nuanced interpretations of cognitive data when factoring in socio-demographic influences. While biological contributions exist, environmental factors significantly compound gendered cognitive disparities across lifespan.
Proposed interventions targeting specific cognitive decline avenues, accounting for gendered differences in anxiety and substance use prevalence, may improve overall cognitive health outcomes.

An extensive examination of over 45,000 individuals reveals complex interactions between cognitive development, aging, gender, and environmental factors, necessitating a holistic approach to understanding cognition across the lifespan.

Available online detailing methodology and full results findings, including questionnaires and cognitive assessments used in the study.

Collaboration among authors for study conception, methodology, analysis, writing, and supervision, with explicit academic roles defined in the research process.