Transcranial direct-current stimulation (tDCS) — a non-invasive technique for applying electric current to areas of the brain — may be growing in popularity, but new research suggests that it probably does not add any meaningful benefit to cognitive training. The study is published in Psychological Science, a journal of the Association for Psychological Science.
“Our findings suggest that applying tDCS while older participants engaged in daily working memory training over four weeks did not result in improved cognitive ability,” explains researcher Martin Lövdén of Karolinska Institutet and Stockholm University.
“The study is important because it addresses what has arguably been the most promising cognitive application of tDCS: the possibility of long-term cognitive enhancement from relatively limited practice on select cognitive tasks,” Lövdén adds. “Cognitive enhancement is of interest not just to scientists, but also to the student studying for final exams, the gamer playing online games, and the retiree remembering which pills to take. Because of this large audience, it is of utmost importance to conduct systematic research to disentangle hype from fact.”
Working memory — our capacity for holding information in mind at any given moment — underlies many fundamental cognitive processes and is linked with some aspects of intelligence. Research has shown that working memory training improves working memory performance but it’s unclear whether this specific training can yield improvements to broader cognitive abilities.
Recent interest and publicity surrounding the potential effects of tDCS — which involves conducting a weak electrical current to the brain via electrodes on the scalp — led Lövdén and colleagues to wonder: Could using tDCS during cognitive training enhance brain plasticity and enable transfer from working memory to other cognitive processes?
The researchers enrolled 123 healthy adults who were between 65 and 75 years old in a 4-week…