Scientists hint at reversing decline in working memory using electrical stimulation

April 11, 2019 0 By FM

Electrostimulation can improve the working memory of people in their 70s making them perform memory tasks similar to that of 20-year-olds, according to new research published in Nature Neuroscience.
“Age-related changes are not unchangeable,” said lead researcher Robert Reinhart, a neuroscientist at Boston University, to The Guardian.

“We can bring back the superior working memory function that you had when you were much younger.”

The study involved 42 people aged 20–29 years and 42 people aged 60–76 years and were assessed in a working memory task.

The research focused on a part of cognition called working memory, the brain system that holds information for short periods while we are making decisions or performing calculations. Working memory is crucial for a wide variety of tasks, such as recognising faces, solving math and exploring a new environment.

Working memory is known to steadily decline with age. A disconnection between the two brain networks known as the prefrontal and temporal regions is considered as the factor contributing to the decline in this memory.

In young people, the electrical brain activity in these two regions tends to be rhythmically synchronised, which researchers think allows information to be exchanged between the two brain areas. However, in older people the activity tends to be less tightly synchronised. This may be as result of deterioration of the long-range nerve connections that link up the different parts of the brain.

The older cohort showed to be slower and less accurate in the tests. The scientists then subjected the older participants to 25 minutes of non-invasive brain stimulation which was delivered through scalp electrodes and personalized to their individual brain circuits. The stimulation was aimed to synchronise the two target brain regions by passing gentle pulses of electricity through the scalp and into the brain.

After the intervention, working memory in the older adults showed to improve well up to match the younger group. The effect was reported to last for 50 minutes after the stimulation. Those who had scored worst to start with showed the largest improvements.

“We’re seeing the largest improvements in people with the greatest deficits at baseline,” said Reinhart. “That really bodes well for clinical work in people with these types of cognitive brain disorders.”

Though the results were considered as promising, Reinhart stated that larger studies would be needed to confirm the findings and assess how they might be applied clinically.