“Evidence against Benefits from Cognitive Training and Transcranial Direct Current Stimulation in Healthy Older Adults”, Kristina S. Horne, Hannah L. Filmer, Zoie E. Nott, Ziarih Hawi, Kealan Pugsley, Jason B. Mattingley, Paul E. Dux2020-10-26 (; similar)⁠:

Cognitive training and brain stimulation show promise for ameliorating age-related neurocognitive decline. However, evidence for this is controversial.

In a Registered Report, we investigated the effects of these interventions, where 133 older adults were allocated to 4 groups (left prefrontal cortex anodal transcranial direct current stimulation (tDCS) with decision-making training, and 3 control groups) and trained over 5 days. They completed a task/questionnaire battery pre-training and post-training, and at 1- and 3-month follow-ups. COMT and BDNF Val/Met polymorphisms were also assessed.

Contrary to work in younger adults, there was evidence against tDCS-induced training enhancement on the decision-making task. Moreover, there was evidence against transfer of training gains to untrained tasks or everyday function measures at any post-intervention time points.

As indicated by exploratory work, individual differences may have influenced outcomes. But, overall, the current decision-making training and tDCS protocol appears unlikely to lead to benefits for older adults.