Adults age 65 and older who completed five to six weeks of cognitive speed training were less likely to be diagnosed with dementia, according to new findings published earlier this month in Alzheimer’s & Dementia: Translational Research and Clinical Interventions.

Researchers used speed of processing training, which helps people quickly find visual information on a computer screen and handle increasingly complex tasks in a shorter time period. This first of its kind study assessed the risk of developing dementia, including Alzheimer’s disease, 20-years after participating in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, which was originally conceptualized and led by Sherry Willis, PhD, a professor emeritus in our department and senior author on this publication.

Dr. Willis and her co-investigators enrolled 2,802 adults into the ACTIVE study in 1998–1999 to assess long-term benefits of participants randomized to three different types of cognitive training — memory, reasoning, and speed of processing — in comparison to a control group who received no such training. In the three groups, participants received up to 10 sessions of 60 to 75 minutes of cognitive training that took place over five to six weeks. Additionally, half of participants were randomized to receive up to four additional cognitive training sessions, or boosters, which took place 11 and 35 months after the initial training.

When investigators examined Medicare records of the three groups of participants 20 years later, they found that participants in the dual-attention speed game had a 25% reduction in dementia diagnoses compared with the control group. But this benefit was only for the subset of volunteers who had the original speed game training plus the booster sessions.

“Seeing that boosted speed training was linked to lower dementia risk two decades later is remarkable because it suggests that a fairly modest intervention can have long-term effects,” says Marilyn Albert, PhD, the corresponding study author and director of the Alzheimer’s Disease Research Center at Johns Hopkins Medicine.

The split-attention speed brain game was developed by professors in Alabama and Kentucky and sold in 2008 to the owners of BrainHQ, a for-profit brain-training company. The updated game now goes by the name Double Decision. Other brain-training companies have also developed similar speed games.

The authors explain that speed training may have been particularly effective because the program was adaptive, meaning that as people improved, the game got harder. Additionally, speed training drives implicit learning (an unconscious habit or a skill, like riding a bike), while memory training and reasoning training drive explicit learning (more like learning facts and strategies). Scientists know that implicit learning works very differently in the brain than explicit learning, and this may contribute to the results seen with dementia in the current analysis.