Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults – A Pilot Study

Abstract

Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60–72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.

Working Memory From the Psychological and Neurosciences Perspectives: A Review

“…Other than the presented interaction effects of age and emotions, caffeine, and hormones, other studies looked at working memory training in the older population in order to investigate working memory malleability in the aging brain. Findings of improved performance for the same working memory task after training were consistent across studies ( Dahlin et al, 2008 ; Borella et al, 2017 ; Guye and von Bastian, 2017 ; Heinzel et al, 2017 ). Such positive results demonstrated effective training gains regardless of age difference that could even be maintained until 18 months later ( Dahlin et al, 2008 ) even though the transfer effects of such training to other working memory tasks need to be further elucidated as strong evidence of transfer with medium to large effect size is lacking ( Dahlin et al, 2008 ; Guye and von Bastian, 2017 ; Heinzel et al, 2017 ; see also Karbach and Verhaeghen, 2014 ).…”

Contribution of the Lateral Prefrontal Cortex to Cognitive-Postural Multitasking

“…This again enables participants to allocate more attention to concurrent tasks, resulting in better performance in this task. Also, during working memory tasks, an increase in fronto-parietal neural activation with increasing cognitive load has been described in terms of an adaptive mechanism in younger adults ( Nagel et al, 2011 ; Heinzel et al, 2014 ; Heinzel et al, 2017 ). Accordingly, our findings further contribute to the idea that individuals who vary in their cognitive abilities might compensate for this by investing greater effort.…”

N‐back training and transfer effects revealed by behavioral responses and EEG

“…Cognitive training was developed to improve different cognitive functions such as attention, perception, and memory in young and older adults (Heinzel, Rimpel, Stelzel, & Rapp, ; Loosli et al, ; Mahncke, Bronstone, & Merzenich, ; Salminen, Kühn, Frensch, & Schubert, ), and to tap into the aging brain's plasticity to improve cognitive functions such as intelligence, episodic memory, WM, and executive functions (Dahlin, Nyberg, Bäckman, & Neely, ; Lawlor‐Savage & Goghari, ; Yang et al, ). Moreover, WM training has been shown to yield beneficial effects in older adults reducing age‐related WM decline (Borella, Carretti, Riboldi, & De Beni, ; Borella, Carretti, Zanoni, Zavagnin, & De Beni, ; Brehmer, Westerberg, & Bäckman, ; Buschkuehl, Jaeggi, & Jonides, ; Li et al, ; Schmiedek, Lövdén, & Lindenberger, ), albeit that only a few cognitive training studies, in terms of N ‐back training, have shown positive effects across age (Heinzel et al, ; Lawlor‐Savage & Goghari, ; Loosli et al, ). Following a series of studies, Dahlin, Neely, Larsson, Bäckman, and Nyberg (), Dahlin, Nyberg, et al () and Li et al () reported that training on an N ‐back task improves WM of both young and older healthy subjects.…”

“…, albeit that only a few cognitive training studies, in terms of N-back training, have shown positive effects across age (Heinzel et al, 2017;Lawlor-Savage & Goghari, 2016;Loosli et al, 2016). Following a series of studies, Dahlin, Neely, Larsson, Bäckman, and Nyberg (2008), and Li et al (2008) reported that training on an N-back task improves WM of both young and older healthy subjects.…”