Scientists report the first convincing evidence in humans that cognitive training can increase levels of a brain chemical that typically decreases with age.
A 10-week study with people aged 65 or older found that doing rigorous mental exercises for 30 minutes a day increased levels of the chemical messenger acetylcholine by 2.3% in a brain area involved in attention and memory.
The increase “is not huge,” says Étienne de Villers-Sidani, a neurologist at McGill University in Montreal. “But it’s significant, considering that normally there’s a 2.5% reduction per decade just from aging.”
So, at least in that brain area, cognitive training seemed to turn back the clock by about 10 years.
The chemical change observed after intensive brain training is persuasive, says Michael Hasselmo, director of the Center for Systems Neuroscience at Boston University, who did not participate in the study.
“It was convincing enough that I thought: ‘Maybe I need to do this,’” he says.
The result supports previous research in animals showing that brain-stimulating environments can increase levels of certain neurotransmitters. Human studies have suggested that cognitive training can improve thinking and memory.
Never Skip Brain Day
The study, funded by the National Institutes of Health, comes amid the proliferation of online brain training programs, including Lumosity, Elevate, Peak, CogniFit and BrainHQ.
But it’s been hard to know if these programs really work, says de Villers-Sidani, who directs the cognitive disorders clinic at McGill’s Montreal Neurological Institute.
“They had a positive impact on some cognitive measures,” he says, “but then the question came: how much are they changing the brain and how are they changing the brain?”
So de Villers-Sidani and a team of researchers decided to see if mental exercise could increase levels of acetylcholine, a neurotransmitter closely associated with cognitive performance.
Acetylcholine levels typically begin a gradual decline around midlife. Levels drop sharply, however, in people with Alzheimer’s disease.
The team studied 92 healthy people aged 65 or older.
Half of the participants spent 30 minutes a day playing computer games like solitaire and Candy Crush.
The others spent the same amount of time each day doing cognitive exercises that are part of the scientifically tested BrainHQ program. The program challenges users to remember the type and location of items that appear and disappear at increasing speeds.
“It’s really targeted at attention and processing speed, and it kind of pushes you to the limit,” says de Villers-Sidani.
The researchers used a special type of PET scan to detect changes in acetylcholine levels in the anterior cingulate cortex, a brain region important for decision-making and error detection.
“I wasn’t sure we’d find anything, to be honest,” says de Villers-Sidani.
But they did. In people who played games like solitaire, acetylcholine levels remained unchanged. But in those who did cognitive training, there was a significant increase.
Acetylcholine levels also increased in other brain areas, including the hippocampus, which plays a key role in memory.
Even modest changes are significant, says Hasselmo, because acetylcholine does more than carry messages in the brain. It also modulates neuron behavior in ways that affect learning, memory and attention.
So, when a person takes, say, a high dose of the motion sickness drug scopolamine — which blocks the effects of acetylcholine — things start to go wrong.
“If you block the neuromodulatory function in the brain, the person can’t even think,” says Hasselmo. “You enter a delirious state.”
On the other hand, even small increases in acetylcholine can have a “profound and remarkable” effect on memory and thinking in older adults.
Hasselmo notes that the first Alzheimer’s drugs reduced symptoms by increasing acetylcholine levels. Now, he says, intensive brain training has the potential to achieve similar gains and slow cognitive decline.
Source: npr.org by Jon Hamilton