AFTER FOUR DAYS OF ELECTRICAL STIMULATION, study participants had better information recall for up to a month. A recent Boston University (USA) study showed that zapping the brains (with repeated electrical currents) of adults over 65 led to memory improvements lasting up to a month. Today we explore how brain stimulation can improve short-term memory.
As I approach 60, my memory is fading in subtle ways. Have you ever walked into a room and had a moment in which you could not remember why you were there? The new research caught my attention in this context. I have written about ways to improve your memory but did not have electrical stimulation, a simple and drug-free approach, on the list.
Brain stimulation and memory
The study authors remind us that historical studies suggest that long-term memory and “working” memory — which allows the brain to store information temporarily — are controlled by distinct mechanisms and structures of our brain.
The research team used a non-invasive method of brain stimulation. With transcranial alternating current stimulation (tACS), the researchers delivered electrical currents through electrodes placed on the scalp.
One hundred and fifty participants, aged 65 to 88, tried to recall lists of 20 words read aloud by an experimenter. The participants had tACS for the entire 20 minutes of the task.
Here are the research findings:
The high-frequency electrical currents stimulated the dorsolateral prefrontal cortex, a region near the brain’s front. This stimulation improved long-term memory while stimulating the parietal lobe (further back in the brain) and improved working memory.
Let’s get into the details. The prefrontal cortex stimulation improved the ability to recall words from the beginning of the lists, a long-term memory task. Low-frequency stimulation to the lower parietal lobe enhanced recall of items later in the lists, a task involving working memory.
The memory performance improved over the four days, and the improvements persisted for up to a month. Individuals with the lowest general cognitive function before the study had the largest memory gains.
I became less skeptical of the results when I saw that using a “sham” protocol (in subjects had current application only briefly at the start and end of a task to mimic the sensation of brain stimulation) did not enhance memory.
My take — Brain stimulation and memory
First, kudos to the researchers for a well-done study. The scientists conducted a randomized, double-blind study (that included two sham-controlled experiments) to target memory function in older adults. They did an additional test to test the reproducibility of the findings.
Unlike previous studies, the authors used low-energy stimulation for several consecutive days rather than for a single session. The researchers also targeted folks over 65.
I am curious whether brain stimulation helps with other memory types. And will the memory improvements persist longer than one month? What about its use for dementia, such as Alzheimer’s disease?
Thank you for joining me for a peek at brain stimulation and memory.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
