Working Memory Training and Transfer: Theoretical and Practical Considerations

Working memory training improves episodic memory in older people: transfer based on controlled retrieval processes

Introduction

The results of working memory (WM) training to improve episodic memory in older people are inconsistent. This inconsistency could be due to the fact that the episodic memory tests used do not share the same cognitive resources as the trained WM task. The aim of this study was to assess whether performance on an episodic memory test will improve only when this test requires controlled processes of retrieval of information from secondary memory or recollection, similar to the processes exercised during WM training.

Method

Fifty-five people over 60 years of age participated in the study: 27 were randomly assigned to the experimental group (EG) and the rest to the control group (CG). The EG was trained in complex span tasks. Before and after training, both groups were tested on episodic memory tests (a verbal and a visuospatial recognition test) and WM span tasks (reading, digit and spatial location).

Results

ANOVAs revealed a greater improvement of recollection estimates in the EG than in the CG for both verbal recognition (p = 0.023) and visuospatial recognition (p = 0.014).

Discussion

Our results provide support for a cognitive mechanism whose shared presence favored transfer from training on a WM task to a test of episodic memory. Consistent with our predictions, training on complex span tasks improved performance on recognition tests only when recall required a controlled search process in secondary memory, or recollection. We therefore stress the importance of identifying other cognitive resources that are susceptible to transfer from a training task to other untrained tasks. A better understanding of the phenomenon of transfer is crucial for the design of increasingly effective intervention programs for older people.

Effects of working memory training on cognitive and academic abilities in typically developing school-age children

Process-based working memory (WM) training in typically developing children usually leads to short- and long-term improvements on untrained WM tasks. However, results are mixed regarding far transfer to academic and cognitive abilities. Moreover, there is a lack of studies jointly evaluating the different types of transfer, using an adequate design and considering motivational factors. In addition, evidence is needed about how pre-training performance is related to individual differences in training-induced transfer. Therefore, this study aimed to implement and evaluate the efficacy of a computerized process-based WM training in typically developing school-age children. Near and far transfer effects were evaluated both immediately after training and after 6 months, as well as individual differences in training-induced transfer. The sample was composed of 89 typically developing children aged 9-10 years (M = 9.52, SD = 0.30), who were randomized to a WM training group or an active control group. They were evaluated at pre-training, post-training, and follow-up phases with measures of visuospatial and verbal WM, reading comprehension, math computation, and fluid intelligence. Results showed that the training group significantly improved performance in verbal WM and fluid intelligence compared to the active control group, immediately after training and after 6 months. Trained children with lower initial performance in verbal WM or fluid intelligence showed greater transfer gains. No group differences were found in motivational factors. Findings of this study suggest that process-based WM training may promote transfer to cognitive abilities and lead to compensation effects of individual differences in typically developing school-age children.

A Game a Day Keeps Cognitive Decline Away? A Systematic Review and Meta-Analysis of Commercially-Available Brain Training Programs in Healthy and Cognitively Impaired Older Adults

The rising prevalence rates of age-related cognitive impairment are a worldwide public concern, bringing about a surge in the number of "brain training" programs commercially available to the general public. Numerous companies advertise that their products improve memory and protect against cognitive decline, though researchers have voiced concerns regarding the validity of such claims. To address this issue, the current meta-analytic investigation examined evidence from 43 studies (encompassing 2,636 participants) to evaluate the efficacy of commercial training programs within two separate populations: healthy older adults and older adults with mild cognitive-impairment (MCI). Seven programs were identified: BrainGymmer, BrainHQ, CogMed, CogniFit, Dakim, Lumosity, and MyBrainTrainer. Analyses yielded small, significant near-transfer effects for both healthy and MCI samples. Far-transfer was not observed for the MCI sample, whereas a small, significant effect was found for subjective but not objective measures of far-transfer in the healthy sample. Analyses of individual domains (combining near-and far-transfer outcomes) yielded significant transfer to executive-functioning, memory, and processing-speed in healthy older adults. After adjusting for publication bias, only the effect size for processing speed remained significant. Transfer to attention, objective everyday functioning, fluid-intelligence, and visuospatial domains was not significant. Thus, whilst "brain training" may be suitable for enjoyment and entertainment purposes, there is currently insufficient empirical evidence to support that such training can improve memory, general cognition, or everyday functioning. This area of research is still in its infancy and warrants further investigation to provide more substantial evidence regarding the efficacy of this rapidly expanding industry.

Working memory training restores aberrant brain activity in adult attention-deficit hyperactivity disorder

The development of treatments for attention impairments is hampered by limited knowledge about the malleability of underlying neural functions. We conducted the first randomized controlled trial to determine the modulations of brain activity associated with working memory (WM) training in adults with attention-deficit hyperactivity disorder (ADHD). At baseline, we assessed the aberrant functional brain activity in the n-back WM task by comparing 44 adults with ADHD with 18 healthy controls using fMRI. Participants with ADHD were then randomized to train on an adaptive dual n-back task or an active control task. We tested whether WM training elicits redistribution of brain activity as observed in healthy controls, and whether it might further restore aberrant activity related to ADHD. As expected, activity in areas of the default-mode (DMN), salience (SN), sensory-motor (SMN), frontoparietal (FPN), and subcortical (SCN) networks was decreased in participants with ADHD at pretest as compared with healthy controls, especially when the cognitive load was high. WM training modulated widespread FPN and SN areas, restoring some of the aberrant activity. Training effects were mainly observed as decreased brain activity during the trained task and increased activity during the untrained task, suggesting different neural mechanisms for trained and transfer tasks.