The effect of high vs. low intensity neuropsychological treatment on working memory in patients with acquired brain injury.

AIM: To evaluate the combined effect of compensation therapy and functional training on working memory (WM) in patients with acquired injury and chronic cognitive deficits by investigating the dose-response relationship and specificity of transfer effects. RESEARCH DESIGN: Double-blind randomized controlled trial. METHODS: All patients underwent 4 weeks of compensation therapy in a day-care setting. In addition, they received either 20 sessions of computer-based WM training (n = 11) or attention training (n = 9). Transfer effects on cognition and their functional relevance in daily life were assessed before treatment, after 2 weeks (10 additional training sessions), and after 4 weeks (20 additional training sessions) of therapy. RESULTS: The combined treatment led to significant improvements in WM performance, verbal memory, and self-reported changes in daily life. The amount of training was identified to modulate efficacy: Significant improvements showed only in the later training phase. We observed no differences between the two training schemes (WM vs. attentional training). CONCLUSIONS: Even in the chronic phase after brain lesion WM performance can be enhanced by the combination of compensation therapy and computerized cognitive training when applied intensely; both a more general attention and a specific WM training regimen are effective.

WOME: Theory-Based Working Memory Training - A Placebo-Controlled, Double-Blind Evaluation in Older Adults.

Background: Scientifically evaluated cognitive intervention programs are essential to meet the demands of our increasingly aging society. Currently, one of the "hottest" topics in the field is the improvement of working memory function and its potential impact on overall cognition. The present study evaluated the efficacy of WOME (WOrking MEmory), a theory-based working memory training program, in a double-blind, placebo-controlled, and randomized controlled trial (www.drks.de, DRKS00013162). Methods:N = 60 healthy older adults were allocated to (1) the WOME intervention, (2) an active low-level intervention, or (3) a passive control group. Overall, the intervention groups practiced twelve sessions of 45 min within 4 weeks of their respective training. Transfer effects were measured via an extensive battery of neuropsychological tests and questionnaires both pre-/post-training and at a 3-month follow-up. Results:WOME led to a significant improvement in working memory function, demonstrated on a non-trained near transfer task and on two different composite scores with moderate to large effect sizes. In addition, we found some indication of relevant impact on everyday life. The effects were short-term rather than stable, being substantially diminished at follow-up with only little evidence suggesting long-term maintenance. No transfer effects on other cognitive functions were observed. Conclusion:WOME is an appropriate and efficient intervention specifically targeting the working memory system in healthy older adults. Trial Registration: German Clinical Trials Register (DRKS), Identifier: DRKS00013162.

Can impaired working memory functioning be improved by training? A meta-analysis with a special focus on brain injured patients.

OBJECTIVE: Deficits in working memory (WM) are commonly observed after brain injuries and cause severe impairments in patients' everyday life. It is still under debate if training can enhance or rehabilitate WM in case of malfunction. The current meta-analysis investigates this issue from a clinical point of view. It addresses under which conditions and for which target group WM training may be justifiable. METHOD: Relevant WM training studies were identified by searching electronic literature databases with a comprehensive search term. In total, 103 studies, which added up to 112 independent group comparisons (N = 6,113 participants), were included in the analysis. RESULTS: Overall, WM training caused a moderate and long-lasting improvement in untrained WM tasks. Moreover, improvement of WM functioning led to sustainable better evaluation of everyday life functioning, however, effect sizes were small. Concerning transfer effects on other cognitive domains, long-lasting improvements with small effect sizes were observed in cognitive control and reasoning/intelligence. In contrast, small immediate, but no long-term effects were found for attention and long-term memory. Studies with brain injured patients demonstrated long-lasting improvements in WM functions with moderate to large effect sizes. A main moderator variable of intervention efficacy is the number of training sessions applied. CONCLUSION: WM training produces long-lasting beneficial effects which are strongly pronounced in patients with acquired brain injuries. This finding supports the application of WM training in clinical settings. To determine optimal training conditions, future studies must systematically investigate the characteristics of interventions as they are at present inevitably confounded.