Neuroscientists at the University of Boston have shown that the short-term working memory of the elderly can be made as effective as that of the young. For this, scientists non-invasively stimulated the brain with an electric current. The memory of the test subjects started to work at least 50 minutes better after a power failure.
The short-term working memory is comparable to the RAM of the computer. We use it when, for example, we solve a mathematical problem, remember the address that is dictated to us, or just support the conversation.
The person applies the information stored in the working memory in the short term as long as he needs it, and then he "erases" or translates it into the long term. This type of memory is therefore the most important in terms of both daily life and for solving various tasks. But unfortunately the working memory efficiency decreases with age.
In the new work, scientists have discovered how the effectiveness of working memory can be stimulated in the short term without the help of medication. They discovered what exactly happens in the cerebral cortex when the working memory starts to deteriorate.
To do this, the researchers conducted a series of experiments with young people (42 people aged 20 to 29 years old) and elderly people (42 people aged 60 to 76 years old). All test subjects were given a simple memorization task: first they were shown an image and after 3 seconds they were shown again – or they were replaced by another. The participants in the experiment had to tell which image they were shown for the second time, the same or new. Scientists have followed the brain activity of all test subjects with the help of an electro-encephalogram.
The main difference between what happens in a young and an older person's brain at the time of image recognition is the level of synchronization between the areas of the cerebral cortex.
In this case, the neurons of the prefrontal cortex interact in particular with the neurons of the temporal zone. For young people, this interaction is expressed much more clearly.
To allow the brain cells to "communicate" more with each other, the researchers acted alternating current on the basis of the experiment participants. The authors synchronized his frequency with the individual rhythms of the brain of a certain person. The action of the current subjects felt like a slight tingling of the scalp during the first 30 seconds of the experiment. The stimulation itself lasted 25 minutes, after which both young and old participants again performed tasks to check the working memory. At the same time, the young subjects felt that their brains were stimulated to the same extent as the brains of the older "colleagues": special caps with electrodes were placed on their heads, but no power was applied to them.
As a result, the results of the group of elderly subjects after stimulation approximated the results of the group of young people: 90% of the correct answers versus 80% before stimulation. In addition, repeated tasks after 50 minutes after the delivery of current older participants
The authors of the work plan bring the results to the development of a working memory correction method that can be used in various pathologies and to combat age-related changes in the brain.