Proximal improvement and higher-order resting state network change after multidomain cognitive training intervention in healthy older adults

Abstract

Prior randomized control trials have shown that cognitive training interventions resulted in improved proximal task performance, improved functioning of activities of daily living, and reduced dementia risk in healthy older adults. Neural correlates implicated in cognitive training include hub brain regions of higher-order resting state networks including the default mode network, dorsal attention network, frontoparietal control network, and cingulo-opercular network. However, little is known about resting state network change after cognitive training, or the relation between functional brain changes and improvement in proximal task performance. We assessed the 1) change in proximal task performance, 2) change in higher-order resting state network connectivity via functional magnetic resonance imaging, and 3) association between these variables after a multidomain attention/speed-of-processing and working memory randomized control trial in a sample of 58 healthy older adults. Participants in the cognitive training group improved significantly on seven out of eight training tasks immediately after the training intervention with the largest magnitude of improvement in a divided attention/speed-of-processing task, the Double Decision task. Only the frontoparietal control network had significantly strengthened connectivity in the cognitive training group at the post-intervention timepoint. Lastly, higher frontoparietal control network connectivity was associated with improved Double Decision task performance after training in the cognitive training group. These findings show that the frontoparietal control network may strengthen after multidomain cognitive training interventions, and this network may underlie improvements in divided attention/speed-of-processing proximal improvement.

Keywords: Cognitive aging; Cognitive training; Functional connectivity; Resting state networks.

Fig. 1

Study timeline

Fig. 2

Visualization of centroid point and connections of each resting state network. A Anterior, B superior, and C right hemisphere view [12]

Fig. 3

Attention/speed-of-processing individual change and distribution of cognitive training and education control groups at pre-intervention (baseline) and post-intervention (3-month) timepoints (n = 58 for all panels). Data are unstandardized residuals controlling for tDCS group, study site, age, sex, education, and mood change. * = high magnitude of change (partial η² > 1.6). A Hawk Eye, B Divided Attention, C Target Tracker, D Double Decision. Tasks with an outcome variable of milliseconds are identified in the title of the y-axis [A, B, and D]. For interpretation, lower scores reflect better performance for these tasks

Fig. 4

Working memory individual change and distribution of cognitive training and education control groups at pre-intervention [baseline] and post-intervention [3-month] timepoints [n = 58 for all panels]. Data are unstandardized residuals controlling for tDCS group, study site, age, sex, education, and mood change. * = high magnitude of change [partial η² > 1.6]. A To Do List, B Memory Grid, C Auditory Ace, D Card Shark

Fig. 5

Resting state network individual change and distribution of cognitive training and education control groups at pre-intervention [baseline] and post-intervention [3-month] timepoints [n = 58 for all panels]. Data are unstandardized residuals controlling for tDCS group, study site, age, sex, education, and mood change. A Frontoparietal control network [FPCN], B cingulo-opercular network [CON], C default mode network [DMN], D dorsal attention network [DAN]

Fig. 6

The association of frontoparietal control network difference [FPCN] and cognitive training task difference with tasks that had a high magnitude of improvement after training with 95% confidence intervals in cognitive training group only [n = 30 for all panels]. A Double Decision, B To Do List, C Memory Grid, D Auditory Ace, E Card Shark. r² reflects variance explained from the correlation between FPCN difference and cognitive training difference variables controlling for tDCS group, study site, age, sex, education, and mood change. β = standardized beta. * = significant association of p < .05