How exercise affects our memory

According to a promising new study on exercise, memory and aging, a unique moderate workout can immediately change how our brain works and our ability to recognize common names and similar information.

The study adds to the growing evidence that exercise can have quick effects on brain function and that these effects could accumulate and lead to long-term improvements in the functioning of the brain. our brain and our memories.

Until recently, scientists thought that in adulthood, the structure and function of human brains were relatively fixed, particularly in relation to malleable tissues, such as muscles, that develop and grow. Shrivel continuously in direct response to the way we live.

But many more recent experiments have shown that the adult brain can actually be quite plastic, rewire and reshape itself in different ways, depending on our lifestyles.

Exercise, for example, is known to affect our brains.

In animal experiments, exercise increases the production of neurochemicals and the number of newborn neurons in the mature brain and enhances the animal's ability to think.

Similarly, in humans, studies show that regular exercise gradually increases the volume of the hippocampus, a key element of brain memory networks. It also improves many aspects of people's thinking.

However, important questions remain regarding exercise and the brain, including the temporal evolution of any change and its durability, ie whether there are short-term changes or, with continuous training, durable.

This particular issue intrigued scientists from the University of Maryland. They had already published a 2013 study of older people about the long-term effects of exercise on parts of the brain involved in semantic memory processing.

Semantic memory is, in essence, our knowledge of the world and culture of which we are a part.

It represents the context of our lives – an accumulation of common names and concepts, such as "what is the blue color?" Or "who is Ringo Starr?".

It can also be ephemeral. As people get older, semantic memory is often one of the first forms of memory to disappear.

But Maryland scientists had discovered in their previous study that a 12-week treadmill program changed the way parts of the brain involved in semantic memory worked.

After four months of exercise, these parts of the brain became less active during semantic memory tests, which is a desirable outcome.

Less activity suggests that the brain has become more efficient at semantic memory processing as a result of exercise, requiring fewer resources to access memories.

For the new study published in April in the Journal of the International Society of Neuropsychology, scientists decided to go back and badyze the steps needed to achieve this state.

Specifically, they wanted to see how a single workout could change the way the brain treats semantic memories.

They recruited 26 healthy men and women aged 55 to 85, who did not have serious memory problems, and asked them to go to the exercise lab twice. There, they rested quietly or did 30 minutes of exercise bike, a training that scientists hoped could stimulate, but not exhaust.

Then, the volunteers expanded into an MRI brain scanner and saw the names scrolling on the screen of a computer. Some names were famous, such as, for example, Ringo Starr, while others were removed from the local phone book.

Famous names are an important part of semantic memory, and volunteers were asked to press a key on the screen to recognize celebrity names and a different touch when the name was unknown to them. Meanwhile, the researchers followed their brain activity as a whole, as well as in the parts involved in the processing of semantic memory.

Scientists expected that the areas needed for semantic memory work would be calmer after exercise, just like after weeks of work, says J. Carson Smith, badociate professor of kinesiology and director of the Exercise for the brain health laboratory of the School of Public Health of the University of Maryland, who oversaw the new study.

But this is not what happened. Instead, the parts of the brain most involved in semantic memory were filled with much more intense activity after exercise than after rest.

At first, the researchers were surprised and intrigued by the results, says Smith. But then, they started thinking that they were observing the beginning of a training response.

"There is an badogy with what happens with the muscles," says Smith.

When he starts exercising, he points out that his muscles are contracting and burning energy. But as they become more fit, these same muscles respond more efficiently and use less energy for the same work.

Scientists suspect in the same way that the peak of brain activity after a first bike session is the prelude to tissue remodeling which, with continuous exercise, improves the function of these areas.

In other words, the memory centers of our brain become more fit.

This study is short-term, however, and does not show the intermediate steps involved in brain change with regular exercise.

It also does not explain how the activity modifies the brain, although Smith thinks that an increase in some neurotransmitters and other biochemicals after the workout needs to play a role.

He and his colleagues hope to examine these questions in future studies and focus on the best types and quantities of exercises to help us keep the memory of this awesome Beatles drummer and all the other cornerstones of our past.