Changes in Neural Activity Underlying Working Memory after Computerized Cognitive Training in Older Adults.

Erich S Tusch,Eliza Ryan,Kirk R Daffner,Phillip J Holcomb,Abdul H Mohammed,Brittany R Alperin

doi:10.3389/fnagi.2016.00255

Abstract

Computerized cognitive training (CCT) may counter the impact of aging on cognition, but both the efficacy and neurocognitive mechanisms underlying CCT remain controversial. In this study, 35 older individuals were randomly assigned to Cogmed adaptive working memory (WM) CCT or an active control CCT, featuring five weeks of five ∼40 min sessions per week. Before and after the 5-week intervention, event-related potentials were measured while subjects completed a visual n-back task with three levels of demand (0-back, 1-back, 2-back). The anterior P3a served as an index of directing attention and the posterior P3b as an index of categorization/WM updating. We hypothesized that adaptive CCT would be associated with decreased P3 amplitude at low WM demand and increased P3 amplitude at high WM demand. The adaptive CCT group exhibited a training-related increase in the amplitude of the anterior P3a and posterior P3b in response to target stimuli across n-back tasks, while subjects in the active control CCT group demonstrated a post-training decrease in the anterior P3a. Performance did not differ between groups or sessions. Larger overall P3 amplitudes were strongly associated with better task performance. Increased post-CCT P3 amplitude correlated with improved task performance; this relationship was especially robust at high task load. Our findings suggest that adaptive WM training was associated with increased orienting of attention, as indexed by the P3a, and the enhancement of categorization/WM updating processes, as indexed by the P3b. Increased P3 amplitude was linked to improved performance; however. there was no direct association between adaptive training and improved performance.

Highlights

Computerized Cognitive Training (CCT)Promoting healthy cognitive aging is a major public health goal
There were no differences between CCT groups on age, sex, Mini Mental State Exam (MMSE) scores, days elapsed between training and post-CCT testing, or any of the baseline neuropsychological tests
While post-CCT change in amplitude and training gain did not correlate when limited to the 1-back task, r = 0.311, n = 35, p = 0.069, there was a strong tendency toward a relationship between performance improvement and P3 amplitude increase. These results indicate that larger post-CCT target P3 amplitude increases were associated with larger post-CCT gains in n-back task performance, and that this relationship was strongest at the highest level of task load

Summary

Introduction

Computerized Cognitive Training (CCT)Promoting healthy cognitive aging is a major public health goal. Caring for older individuals who can no longer manage independently has become a leading public health challenge. In response to these concerns, there is growing interest in developing strategies or interventions that augment intellectual health and for understanding the neural mechanisms that underlie improvement in performance on cognitive tasks. These efforts seem relevant, given the recent preliminary report suggesting that processing speed training in older adults may reduce the risk of developing dementia 10 years later (Edwards et al, 2016)

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