Dementia strikes many people as they age, and there's currently not much we can do about it. It would be nice to think that there could be a fix to stave it off, like a computer game or something that could do more than help you improve at that computer game. Well now, for the first time, it seems like there may be.

The Advanced Cognitive Training in Vital Elderly (ACTIVE) study was a randomized controlled trial in which thousands of healthy seniors got different kinds of cognitive training and had their cognition monitored over ten years. Importantly, the trial was registered at its outset at ClinicalTrials.gov, so even if all of the results were negative (and therefore not likely to be published in an academic journal) they would still be on record and accessible.

After five years, all of the results were in fact negative. But after ten years, one of the interventions reduced dementia risk by about 30 percent.

Participants, mostly white women over 65 (with an average age of 73.5), were randomly assigned to be in one of four groups. The first got nothing. The second got memory training, in which they were taught mnemonic strategies—including forming visual images—for remembering lists and the primary ideas and details of stories. The third got reasoning training, in which they focused on the ability to solve problems and identify and understand patterns. And the fourth got brain-plasticity-based, intensive, adaptive, computerized speed of processing training.

The participants who focused on speed of processing were given a sort of driving simulator where they had to identify which type of vehicle flashed in the center of their screens, as well as locate a road sign that flashed in the periphery. The program was designed to expand peripheral vision and enhance the speed of visual processing, so participants would see more things and see (and presumably respond to) them more quickly. Each group got 10 hour-long sessions over a six-week span.

Speed of processing training turned out to be the big winner. After ten years, participants in this group—and only this group—had reduced rates of dementia compared to the controls. They also reported that they had less difficulty going about their daily lives. The effect was dose dependent; those who underwent more training sessions, and/or booster sessions, as the years wore on saw more dramatic effects. The effect was not seen after five years because not enough members of the control group had developed dementia at that point, so it didn't stand out above the background.

The authors are not exactly clear on how the intervention works but note that speed training is known to strengthen unconscious, implicit memory rather than more conscious memory. They suggest that it may help to build and maintain the connections among neurons that are essential to cognitive function and that tend to falter with age. They also highlight that assessing dementia was not among the initial aims of their study.

So they suggest another trial, one that explicitly sets out to measure the effect of such training on defined criteria related to dementia. Still, identifying flashing cars on your screen has very little downside.

Alzheimer’s & Dementia, 2017. DOI: 10.1016/j.trci.2017.09.002 (About DOIs).