We’ve commented on how marketers are jumping on the “brain fitness” wagon as baby boomers worry about declining cognitive ability in later years. Now the Science Journal column in the Wall Street Journal (sorry, couldn’t find a link to the paid content) reports on a major study that concludes that performing stimulating mental activity doesn’t prevent mental decline with age. Timothy Salthouse from the University of Virginia comments that his studies as well as those conducted elsewhere simply don’t make the case for cognitive decline prevention.
The general conclusion of the article is that the reason older adults with a history of mentally stimulating activity decline more slowly is that their mental capacity was greater to begin with, and the still have plenty of capacity after suffering some loss compared to individuals who lacked that excess capacity. The article isn’t clear on how such “excess capacity” was developed, i.e., was it a genetic gift or was it acquired over a period of time through education, work, etc. The latter seems likely, and if so, it indicates that mental capacity isn’t immutable for life and can, indeed, be enhanced. Perhaps crossword puzzles aren’t the method, though – perhaps it takes many years of daily activity (as in a rigorous education followed by years of challenging work).
I’ve often wondered about the “correlation vs. causation” issue with studies like the Nun Study – in that research, higher functioning individuals were identified from their writings many decades earlier. Nuns that wrote in a more sophisticated and intelligent manner showed much less cognitive decline in later years. While researchers concluded that continued mental stimulation was the key factor, at first glance it would seem this data would also support the “excess capacity” theory.
This study can’t be good news for firms like Posit Science who hope to capitalize on a brain fitness trend. Some firms like Posit are conducting their own research, so we can probably expect dueling studies and continued controversy for a few years.