Investigating the Effects of Spacing on Working Memory Training Outcome: A Randomized, Controlled, Multisite Trial in Older Adults

Abstract

Objective: The majority of the population will experience some cognitive decline with age. Therefore, the development of effective interventions to mitigate age-related decline is critical for older adults' cognitive functioning and their quality of life.

Methods: In our randomized controlled multisite trial, we target participants' working memory (WM) skills, and in addition, we focus on the intervention's optimal scheduling in order to test whether and how the distribution of training sessions might affect task learning, and ultimately, transfer. Healthy older adults completed an intervention targeting either WM or general knowledge twice per day, once per day, or once every-other-day. Before and after the intervention and 3 months after training completion, participants were tested in a variety of cognitive domains, including those representing functioning in everyday life.

Results: In contrast to our hypotheses, spacing seems to affect learning only minimally. We did observe some transfer effects, especially within the targeted cognitive domain (WM and inhibition/interference), which remained stable at the 3-month follow-up.

Discussion: Our findings have practical implications by showing that the variation in training schedule, at least within the range used here, does not seem to be a crucial element for training benefits.

Keywords: Cognitive training; Distributed learning; Transfer.

© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Flowchart of participants and allocation.

Figure 2.

Training performance as a function of spacing condition and intervention group. (A) Working memory-training group. (B) Knowledge-training group. Error bars represent standard errors of the mean.

Figure 3.

Training performance as a function of spacing condition and intervention group in the restricted sample that includes only participants who followed the spacing schedule as defined by using a conservative classification approach (cf. Supplementary Material). (A) Working memory-training group. (B) Knowledge-training group. Error bars represent standard errors of the mean.