Brain stimulation improves memory in the elderly

By stimulating the brains of elderly people for twenty minutes a day with a weak current, they are able to remember information better. Thus, American researchers improved two parts of the memory of 150 elderly people. As a result, they were better able to remember the rows of words that were read aloud, not only immediately after the stimulus, but also a month later.

This provides insight into treatments for normal memory decline in the elderly and possibly even early dementia. write researchers in natural neuroscience.

This is the first time that long-term brain stimulation has been achieved in elderly subjects – between the ages of 65 and 88. Scientists suspected that this was possible because the brain’s plasticity declines over the course of life. Previous studies have shown in recent years that the cognitive skills of younger people improve using different forms of electrical brain stimulation.

The elderly were given a kind of shower cap on their heads that contained several electrodes. The researchers used this to specifically stimulate certain areas of the brain. In other words, an important area of ​​working memory, where information is temporarily stored. Or any other field involved in remembering information from a long time ago.

During the stimulation—which initially caused some twitching—the researchers read five rows of twenty words. The power participants were able to remember more words immediately after the session than the powerless participants. They received this treatment for four consecutive days, and 90 percent of the participants had a slightly better memory each time. Even after a month, the researchers were still able to measure these improvements.

knuckle rhythm

The worse your working memory and long-term memory, the greater the improvements after treatment.

“It’s an exciting and surprising study,” says Alexander Sack, professor of cognitive brain science at Maastricht University.

This is the first time that long-term effects have been achieved using a specific stimulation method: tACS (transcranial alternating current stimulation). “In this method, a weak electric current does not flow from one electrode to another through the brain, but constantly changes the direction of the current at a certain frequency,” Sack explains. The idea is that this facilitates the current electrical rhythm with which brain cells in a particular area communicate with each other. “It’s not yet clear how the long-term effects of TACS appear, but those oscillations, the rhythm of the joint, are what the brain uses to encode and store information,” he says.

This technique is simple, cheap and safe

Alexander Sack professor

The Americans were able to boost the participants’ working memory with a low-frequency rhythm, 4 Hz (four changes per second), in an area diagonally above the left ear (inferior parietal lobule). After twenty minutes of stimulation, the participants were better able to remember the last words they had heard – a sign that their working memory had improved. Long-term memory improved with a high-frequency (60 Hz) rhythm, in an area in the left frontal part of the head (dorsal prefrontal cortex). Then the elders remembered more of the words they had heard first.

Sack anticipates that the form of brain stimulation used will be easy to implement in home situations in the future. “This technology is simple, cheap, and safe and only requires a small battery and some electrodes,” he says. “This can be integrated into a headset.” It is thought not only to improve working memory and other cognitive skills, but also to prevent cognitive decline and early dementia. “The clinical and cognitive effects we see with these forms of brain stimulation are now very reliable.”