Age-Related Decreases in the Retrieval Practice Effect Directly Relate to Changes in Alpha-Beta Oscillations

Abstract

The retrieval (or testing) of information leads to better memory performance compared with reencoding. This phenomenon is known as "testing effect" or "retrieval practice effect" and has been primarily described in behavioral studies with healthy young subjects. However, possible age-related changes and their associated underlying neural processes, in particular neural oscillations, remain unclear. To address this issue, we used a previously established paradigm in healthy young (N ϭ 27) and elderly (N ϭ 28) male and female human adults while their brain activity was being recorded using EEG. Subjects viewed prefamiliarized scene images intermixed with new scenes and classified them as indoor versus outdoor (encoding task) or old versus new (retrieval task). Subsequently, subjects performed a recognition memory task 10 min and 24 h after encoding. Behaviorally, both age groups showed the testing effect at both time points but, importantly, it was less pronounced in the elderly. At the neural level, the retrieval compared with the encoding task was accompanied by power decreases in the alpha (9 -12 Hz) and beta bands (13-30 Hz), possibly reflecting task demands, and this difference was more pronounced in the elderly. Finally, a correlation analysis revealed that those elderly who displayed a more pronounced testing effect exhibited a neural pattern that was more similar to the younger subjects. These findings provide evidence that the testing effect decreases across the life span, and they suggest that changes in alpha-beta oscillations play a direct role.

Retrieval Practice Improves Recollection-Based Memory Over a Seven-Day Period in Younger and Older Adults

“…A further 55 TCI datasets of participants were available and included in the TCI analysis. These data came from an experimental paradigm that was identical except for the response modality in Phases 3 and 4 (confidence ratings instead of recollection/familiarity) as well as the retention interval (one instead of 7 days, Guran et al, 2019).…”

“…The central aim of this study was to investigate the roles of recollection and familiarity in the RPE, and we expected a remember-specific RPE (hypothesis 3). Due to our previous work (Herweg et al, 2018;Guran et al, 2019), we also expected the RPE to be present immediately after RP and a week later (hypothesis 4), irrespective of stimulus Novelty (Cho et al, 2017;Guran et al, 2019) (hypothesis 5). In addition, we explored a possible relationship between Novelty Seeking and the RPE (hypothesis 6).…”

“…A few recent studies indicate that the RPE may be impaired with age: while RP has been shown to still provide memory benefits in older adults (Meyer and Logan, 2013), the benefit is smaller than in young adults (Guran et al, 2019), and sometimes dependents on other characteristics of the task such as feedback (Tse et al, 2010). Thus, in general, the effect appears less robust in older than in young adults, and age-related neurobiological changes might play a role in explaining the behavioral differences in RP between age groups.…”

“…The Episodic Context Account (Karpicke et al, 2014) suggests that the RPE is associated with recreating the initial learning context, updating the context through retrieval, and updating the search set based on successful retrieval. However, this approach struggles to account for the findings of RPEs for novel stimuli: RPEs have been shown to extend even to completely novel stimuli that are shown in a retrieval context (Chan et al, 2006;Cho et al, 2017;Guran et al, 2019). If the RPE relies on a recreation of the learning context, no benefit would be expected for novel stimuli, which have never been encountered.…”

Age-related differences in the temporal dynamics of spectral power during memory encoding

“…Indeed, alpha power (corresponding to the 10-14 Hz band used here) has been linked to holding more items in mind [45] and increases in 10-14 Hz power younger adults show across a list may be an index of elaborative encoding or rehearsal [21]. Alpha (and beta) power have also been linked to age-related differences in memory [46]. Therefore, the smaller increase of 10-14 Hz power in high-performing older adult group relative to the low-performing group may indicate that they are not attempting to engage in elaborative encoding or rehearsal.…”