Just 10 minutes of light physical activity is enough to boost brain connectivity and help the brain to distinguish between similar memories, a new study suggests.
Scientists at the University of California studying brain activity found connectivity between parts of the brain responsible for memory formation and storage increased after a brief interval of light exercise – such as 10 minutes of slow walking, yoga or tai chi.
The findings could provide a simple and effective means of slowing down or staving off memory loss and cognitive decline in people who are elderly or have low levels of physical ability.
The scientists asked 36 healthy volunteers in their early 20s to do 10 minutes of light exercise – at 30% of their peak oxygen intake – before assessing their memory ability. The memory test was then repeated on the same volunteers without exercising.
The same experiment was repeated on 16 of the volunteers who had either undertaken the same kind of exercise or rested, with researchers scanning their brain to monitor activity. In the brains of those who had exercised they discovered enhanced communication between the hippocampus – a region important in memory storage – and the cortical brain regions, which are involved in vivid recollection of memories.
“The memory task really was quite challenging,” said Michael Yassa, a neuroscientist at the University of California, Irvine, and project co-leader. The participants were first shown pictures of objects from everyday life – ranging from broccoli to picnic baskets – and later tested on how well they remembered the images. “We used very tricky similar items to to see if they would remember whether it was this exact picnic basket versus that picnic basket,” he said.
The people who had exercised were better at separating or distinguishing between the different memories, say the scientists writing in the Proceedings of the National Academy of Sciences.
“An evening stroll is sufficient to get some benefit,” said Yassa, adding that the frequency and exact amount of exercise will depend on the person’s age, level of mobility, potential disability and other lifestyle factors.
The scientists also kept track of the participants’ mood changes. “With exercise you do get an enhanced mood. The question is whether that was explaining the effect we got on the behaviour or the effect we got on the brain and it wasn’t,” said Yassa.
Michelle Voss, a neuroscientist at the University of Iowa, described the findings as “intriguing”. “The brain regions involved here are also the regions that are thought to play a big role in the deterioration of memory with ageing. […] It would be really exciting to see this type of experiment in older adults,” she said.