MARY LOUISE KELLY, HOST:
Scientists have produced the first compelling evidence that mental exercise can cause biological changes in a human brain. NPR's Jon Hamilton reports on a new study showing that intensive cognitive training reversed a process associated with aging.
JON HAMILTON, BYLINE: The internet is filled with brain-training programs that promise to improve thinking and memory. But Etienne de Villers-Sidani of McGill University in Canada says it's been hard to know whether they really work.
ETIENNE DE VILLERS-SIDANI: They had a positive impact on some cognitive measures, but then the question was, how much is it changing the brain, and how is it changing the brain?
HAMILTON: So De Villers-Sidani and a team of researchers decided to see whether mental exercise could increase levels of a chemical messenger that's closely associated with cognitive performance. It's called acetylcholine. He says levels tend to fall starting in middle age.
DE VILLERS-SIDANI: For every decade after the age of 40, 45, you get around 2.5% decline in this neurotransmitter in key brain areas.
HAMILTON: The decline is much faster in people with Alzheimer's disease. The researchers studied 92 healthy people who were at least 65 years old. De Villers-Sidani says during the 10-week study, half of the participants spent 30 minutes a day doing mental exercises. These came from a science-backed cognitive training program called Brain HQ.
DE VILLERS-SIDANI: Which is really targeted at attention and speed of processing, and its characteristic is that it kind of pushes you to the limit.
HAMILTON: By asking you to remember more and more in less and less time - other participants spent their time playing video games like Solitaire and Candy Crush. The researchers used a special kind of PET scan to detect changes in acetylcholine levels. De Villers-Sidani says they focused on the anterior cingulate cortex, a brain region that's important for making decisions and detecting errors.
DE VILLERS-SIDANI: I was not sure we would find anything, to be honest.
HAMILTON: But they did. In people who played video games, acetylcholine levels were unchanged. But De Villers-Sidani says in people who did cognitive training, there was a meaningful increase.
DE VILLERS-SIDANI: It was about 2.3%, which is not huge, but it's significant considering that you get a 2.5% decrease per decade, normally just with aging.
HAMILTON: So at least in this brain area, cognitive training appeared to turn back the clock by about 10 years. Acetylcholine levels also increased in other brain areas, including the hippocampus, which plays a key role in memory. The study, funded by the National Institutes of Health, appears in the journal JMIR Serious Games. Michael Hasselmo, a neuroscientist at Boston University, says he was impressed by the result.
MICHAEL HASSELMO: It was compelling enough that I looked up the task myself and thought, maybe I need to be doing this task.
HAMILTON: Hasselmo has spent much of his career studying acetylcholine, which is a chemical messenger that also modulates the behavior of neurons.
HASSELMO: If you block the neuromodulator function in the brain with a drug such as scopolamine, a person can't even think. You basically go into a delirious state.
HAMILTON: Low levels of acetylcholine are a hallmark of Alzheimer's and appear to contribute to the declines in memory and thinking. But Hasselmo says even small increases in this neurotransmitter can noticeably improve cognitive function. He says a cup of coffee boosts levels enough to improve attention and speed up reactions.
HASSELMO: Changing things by 2.5% could have a pretty profound and notable effect even on a subjective level.
HAMILTON: Hasselmo says the first Alzheimer's drugs reduce symptoms by increasing acetylcholine. Now, he says, it looks like hardcore brain training can offer a similar benefit. Jon Hamilton, NPR News.
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