Two Separate, Large Cohorts Reveal Potential Modifiers of Age-Associated Variation in Visual Reaction Time Performance

Abstract

AbstractTo identify individual differences and potential factors influencing age-related cognitive decline and disease, we created MindCrowd. MindCrowd is a cross-sectional web-based assessment of simple visual (sv) reaction time (RT, index of processing speed) and paired-associate learning (PAL, index of verbal episodic memory). svRT and PAL results were combined with 22 survey questions. Analysis of MindCrowd’s svRT data revealed education and reported stroke as potential modifiers of changes in processing speed and memory from younger to older ages (ntotal= 75,666, nwomen = 47,700, nmen = 27,966; ages 18-85 years old, mean (M)Age = 46.54, standard deviation (SD)Age = 18.40). To complement this work, we evaluated complex recognition reaction time (cvrRT) in the UK Biobank cohort (ntotal= 158,249 nwomen = 89,333 nmen = 68,916; ages 40-70 years old, MAge = 55.81, SDAge = 7.72). Similarities between the UK Biobank and MindCrowd were assessed using a subset of the MindCrowd cohort. Labeled UKBb MindCrowd (ntotal= 39,795, nwomen = 29,640, nmen = 10,155; ages 40-70 years old, MAge = 56.59, SDAge = 8.16), this subset was carefully selected to mirror the UK Biobank. An identical linear model (LM) was used to assess both cohorts. The LM revealed similarities between MindCrowd and the UK Biobank across most results, despite obvious cohort differences (e.g., US vs. the UK). Notable divergent findings from the UK Biobank included (1) a first-degree family history of Alzheimer’s disease (FHAD) was associated with longer RTs in only. (2) Compared to being a man with more education, being a woman was associated with longer cvrRT length differences observed from younger to older ages. Divergent results from UKBb MindCrowd include more education and reported smoking. More education was associated with shorter and smoking longer cvrRTs differences observed from younger to older ages. Collected with our prior work, MindCrowd is beginning to reveal the intricate network connecting processing speed, memory, and cognition to healthy and pathological brain aging.