Responses to executive demand in young adulthood differ by APOE genotype

Area of Science:

• Neuroscience
• Cognitive Psychology
• Genetics

Background:

• The Apolipoprotein E (APOE) ε4 allele is linked to cognitive decline but its early-life effects are unclear.
• Previous research on APOE ε4+ cognitive advantages in youth is inconsistent.
• Understanding lifespan cognitive effects of APOE ε4 is crucial for predicting cognitive aging.

Purpose of the Study:

• To investigate if APOE ε4+ confers cognitive advantages in young adults.
• To determine if these advantages are specific to executive functions under varying task demands.
• To explore the nature of cognitive performance differences between ε4+ and ε33 carriers.

Main Methods:

• Recruited young adults aged 18-25 years (21 ε4+, 63 ε33).
• Administered tasks measuring executive functions: verbal fluency, decision-making, prospective memory, and sustained attention.
• Systematically manipulated executive demand within tasks and measured subjective effort.

Main Results:

• Under low executive demand, ε4+ carriers made fewer verbal fluency word repeats.
• Under high executive demand, ε4+ carriers exhibited lower dual-task costs but more switching and root repetition errors.
• ε4+ carriers showed potential working memory updating advantages and different strategic approaches, including speed-accuracy trade-offs.

Conclusions:

• APOE ε4+ may provide cognitive benefits in young adulthood, especially under specific executive demands.
• Performance differences suggest ε4+ influences working memory updating and resource allocation strategies.
• These findings highlight the complex, context-dependent role of APOE ε4 in cognitive aging trajectories.