Lasting benefits have been found for long and short-term memory in the elderly after electrical brain stimulation. Scientists at Boston University in the US hope the breakthrough could lead to the development of non-invasive treatments for those with cognitive disorders like Alzheimer’s.
The researchers administered weak alternating currents to specific regions of the brain in the 150 volunteers, who were aged over 65. Each of them received 20 minutes of stimulus via electrodes inside a skull cap for four consecutive days and heard lists of words they were asked to remember.
Results of the short-term memory tests showed a 65 per cent improvement after four days of stimulating the brain in this way. A month later, recall was 40 per cent better without participants receiving any more treatment.
In the long-term memory exams the volunteers were asked to recall the words minutes after hearing them. In the immediate aftermath of the stimulation, there was a 50 per cent improvement and a month after the last input performance was better by 37.5 per cent.
The participants didn’t report any side effects apart from some itching and tingling at the beginning and end of the stimulation. This subsided after 30 to 60 seconds each time. The research shows promise in tackling memory loss in the elderly.
Robert Reinhart, the project leader, told the Financial Times: “The work has obvious clinical implications. The older people with poor general cognitive functioning coming into the experiment were the individuals who showed the largest improvements during both the intervention and the one-month point.
“[This] bodes well for transferring this [procedure] over to a proper clinical study in people with Alzheimer’s disease who are suffering from more severe memory impairments.”
Two areas of the brain were the focus of the electrical currents: the prefrontal cortex, which is responsible for long-term memory; and the parietal cortex, where short-term memory is processed. A control group of subjects wore placebo caps that did not administer any electrical stimulation.
The electrical signals changed the brainwaves in the areas targeted in a process known as neuroplasty. This enables the organ to adapt and rewire itself, reinforcing new patterns to improve its functioning.
Strings of 20 unconnected words were read to the volunteers, and short-term memory was assessed by the ability to remember words at the end of the list, as those are the ones they’d heard most recently. Being able to recall words from the beginning of the list minutes later indicated good long-term memory.
Dr Reinhart said the next phase of the research would focus on real-world cognitive activities in order to take it outside of a laboratory setting. Tests based on daily living tasks would be relevant for better understanding of how the treatment could potentially reduce the social and economic impact associated with impaired cognition.
Some 900,000 people in the UK are living with dementia, with Alzheimer’s disease being the most common form. There is currently no cure, but diagnosing the condition early can lead to preventative treatments being administered to help slow its progress.