Cognition across the lifespan: age, gender, and sociodemographic influences

Abstract

22 Maintaining cognitive health across the lifespan has been the focus of a multi-billion-dollar industry.23 In order to guide treatment and interventions, a clear understanding of the way that proficiency in 24 different cognitive domains develops and declines across the lifespan is necessary. Additionally, there 25 are gender differences in a range of other factors, such as anxiety and substance use, that are also 26 known to affect cognition, although the scale of this interaction is unknown. Our objective was to 27 assess differences in cognitive function across the lifespan in men and women in a large, 28 representative sample. Over 45,000 individuals were tested on 12 cognitive tasks. Segmented 29 regression was used to model the trajectory of three cognitive domains: short-term memory, verbal 30 abilities, and reasoning. Each domain showed a unique trajectory, suggesting that not all cognitive 31 abilities develop and decline in the same way. Gender differences were found in all three domains; 32 however, after controlling for socio-demographic factors, these differences were greatly reduced or 33 disappeared. These results suggest that the trajectory of cognition across the lifespan differs for men 34 and women, but is greatly influenced by environmental factors. We discuss these findings within a 35 framework that describes gender differences in cognition as likely guided by a complex interplay 36 between biology and environment. 37 38 Introduction 39By 2020, roughly 22% of the world's population will be over 65, a total of approximately 1.7 40 billion people [1]. The consequences of our aging population are many, including an increasing focus 41 on maintaining cognitive health; more so than ever before, individuals are seeking ways to keep their 3 42 minds sharp. This new interest in maintaining cognitive health and reversing, or stalling, normal 43 cognitive decline has led to the creation of billion-dollar industry, promoting products as wide-ranging 44 as "brain training" software and pharmaceutical interventions such as nootropics. Yet, in order to be 45 able to evaluate these approaches as potential tools and treatments, it is important that we first have 46 a clear understanding of how cognition changes across the lifespan in average, healthy individuals.47 Additionally, because of the often-cited cognitive differences between women and men [2-5], it is 48 important to characterize cognition in each population; if gender differences in cognitive abilities do 49 exist, then men and women may respond differently to cognitive aging interventions. 50In healthy individuals, cognitive abilities develop rapidly throughout childhood. By six, most 51 children have developed some degree of inhibitory control, verbal fluency, and task switching [6-8].52 By twelve, they are able to plan and organize, and use conceptual strategies and reasoning [9]. In 53 adolescence, these abilities continue to develop, with most teenagers having good attentional 54 control, verbal fluency, and processing speed [6]. By 18, ex...

Why the use of segmented regression analysis to explore change in relations between variables is problematic: A simulation study.

“…SRA are methods that involve the detection and localization of breakpoints in the relations between two or more variables. SRA have been used to examine the research examples listed above and many more (e.g., Hughes et al, 2019; Lee, 2016; Nichols et al, 2019; O’Reilly et al, 2019). However, exploratory use of SRA is problematic if relations between variables display nonlinearity (e.g., a quadratic relation) instead of piecewise linearity.…”

Thirty-Five Years of Computerized Cognitive Assessment of Aging—Where Are We Now?

“…Having access to such a large number of datapoints also makes it possible to investigate how demographic factors affect cognition in a way and on a scale that was never before feasible, shedding new light on the interplay between biology and environmental factors and their effects on cognitive function. For example, in one recent study of 45,000 individuals, the CBS battery was used to examine the influence of factors like gender differences, anxiety, depression, substance abuse, and socio-economic status on cognitive function, as well as how they interact during the aging process to uniquely affect different aspects of performance [30].…”