Can working memory capacity be expanded by boosting working memory updating efficiency in older adults?

Abstract

Working memory updating (updating) and working memory capacity (WMC) have been assumed to share a common mechanism. However, it is unclear whether WMC can be expanded by boosting the efficiency of updating, particularly during late adulthood. In this randomized controlled study, 33 older adults (aged 60 years and above, M = 69.53, SD = 5.21) were assigned to updating training (n = 17) and contact control (n = 16) groups. In the training group, updating was targeted by a running memory task and a chess game in each training session; whereas in the control group, motivational effects were estimated by their attendance to a series of mental health-related lectures. The boosted updating efficiency was demonstrated by direct training gains over sessions on updating criterion/training tasks, and significant frontocentral inflation at the N2 time range. Near transfer effects were revealed on untrained similar measures immediately after training and partly maintained at a 3-month follow-up. Far transfer effects to WMC were revealed by a significant increase in contralateral delay activity (CDA) ERP measures, although these effects did not manifest on WMC span tasks and other far transfer measures. Note that increased CDA was significantly correlated with the extent of direct gains in updating training. Our findings suggest that updating efficiency can be boosted in older adults; although it has not yet brought about an explicit expansion of WMC in our behavioral measures (i.e., on span tasks), capacity-related neural changes (i.e., on CDA) have nevertheless, started to show up in our short-term updating training program.

Effects of Computerized Updating and Inhibition Training in Older Adults: The ACTOP Three-Arm Randomized Double-Blind Controlled Trial

“…The second objective was to examine whether the training effect generalized to proximal untrained tasks and complex WM tasks. Both inhibition and updating training yielded improvements in proximal updating and inhibition transfer measures, which is consistent with several cognitive interventions in older adults [e.g., (8,(10)(11)(12)(13)(14)]. The magnitude of the pre-post effect was comparable for the two training types.…”

“…One other critical question relates to the impact of updating and inhibition training on transfer tasks. Some studies have found proximal transfer, where improvements following updating training were transferred to an untrained updating task in older adults [e.g., (10)(11)(12)(13)] and training-related improvements in inhibition, which were transferred to an untrained inhibition task (8,14). However, proximal transfer is not systematically observed in older adults (7,14,15).…”

“…This is supported by previous studies where transfer differences were observed between training groups. Because these studies incorporated transfer and training tasks sharing a very similar format and structure, equivalent strategies could be applied [e.g., (10)(11)(12)(13)(14)]. It is therefore possible that our findings differed from these prevous studies, as we incorporated tasks with differing structures to investigate the training-related transfer effect of updating and inhibition processes, rather than focus on learning strategies.…”

Contralateral delay activity is not a robust marker of cognitive function in older adults at risk of mild cognitive impairment

“…The CDA waveform is therefore thought to provide an online index of WM processing (Feldmann‐Wüstefeld, Vogel, & Awh, ). In recent years, the CDA has become increasingly popular as a marker of age‐related WM decline (Du, Ji, Chen, Tang, & Han, ; Schwarzkopp, Mayr, & Jost, ; Wiegand et al, ). Some studies have shown that older adults exhibit reduced differentiation of CDA amplitudes across set sizes relative to younger adults, suggesting that the CDA is sensitive to age‐related cognitive changes (Sander, Werkle‐Bergner, & Lindenberger, ; Stormer, Li, Heekeren, & Lindenberger, ).…”

Contralateral Delay Activity is not sensitive to cognitive decline in older adults at risk of Mild Cognitive Impairment

“…Contralateral delay activity (CDA) is characterised by a negative event-related potential (ERP; time-locked encephalograms) waveform that is sensitive to the number of items maintained in working memory (WM) and persists throughout the retention period (Feldmann-Wustefeld, Vogel, & Awh, 2018). The CDA has become increasingly popular as an index of age-related WM changes (Du, Ji, Chen, Tang, & Han, 2018). However, existing evidence regarding the effects of both age and performance level on CDA amplitudes is equivocal (Jost, Bryck, Vogel, & Mayr, 2011; Sander, Werkle-Bergner, & Lindenberger, 2011; Schwarzkopp, Mayr, & Jost, 2016; Stormer, Li, Heekeren, & Lindenberger, 2013).…”