Shooting electrical current into the brain for just 25 minutes reversed the decline in working memory that comes with aging, scientists reported on Monday. Although the researchers tested the effects on people for only 50 minutes, the finding offers hope for boosting a mental function that is so crucial for reasoning, everyday problem-solving, and planning that it has been called the foundation of intelligence.

By stimulating the brain in precise regions with alternating current (AC), “we can bring back the superior working memory function you had when you were much younger,” psychology researcher Robert Reinhart of Boston University told reporters. “The negative age-related changes [in working memory] are not unchangeable.”

For alternating current, delivered by electrodes embedded in a skull cap, to become a treatment for working memory deficits, however, it would have to overcome a long list of hurdles, starting with proof that it’s safe. But whether or not the findings, published in Nature Neuroscience, result in any practical applications, they provide some of the strongest evidence yet of why older adults aren’t as good at remembering a just-heard phone number or an address in a just-seen text: Brain circuits become functionally disconnected and fall out of synchrony.

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“This is a well-designed, rigorous study,” said neurophysiologist Michael Nitsche of Germany’s University of Göttingen, who reviewed the paper for the journal. “It adds important information about the causal relevance of alterations of [brainwaves] for age-dependent cognitive decline, and it shows that these alterations are reversible.”

Working memory is the sketchpad of the mind, where information — just acquired or hauled up from long-term memory — is weighed, considered, manipulated, and fed into cognitive tasks, from following a conversation to doing mental math. The brain writes on this sketchpad with the oscillations in neuronal firing known as brainwaves, which carry signals within and between the high-level-thinking prefrontal cortex and the temporal lobes, home to the memory-storing hippocampus.

For their experiments, the BU scientists tested the working memories of 42 younger adults (aged 20 to 29) and 42 older ones (60 to 76). People saw an image of, say, an accordion, and 3 seconds later saw it or something else, and then were asked to indicate whether they’d seen it before. Older adults answered correctly about 80% of the time, and younger ones 90%. While people were (presumably) trying to remember the accordion, EEGs monitored their brainwaves, finding significantly less synchronization of the oscillations in older adults than younger ones.

The younger participants then got sham stimulation with alternating current — they wore a cap with electrodes but no current — while older adults got the real deal, in each case for 25 minutes. It feels tingly, but only for 30 seconds or so, and no one could tell sham current from the real kind.

For real AC, the frequency was tuned to the individual brain, matching its natural oscillations so as to synchronize brain waves that, as people age, apparently fall out of sync. “We can tune [the stimulation] to your frequency, your sweet spot,” Reinhart said.

Almost immediately, older adults’ accuracy improved. It quickly reached their younger counterparts’ 90%, and maintained that level for 50 minutes after the stimulation stopped, when the scientists stopped taking measurements. EEG showed that, in the older adults, brain waves between the temporal and prefrontal cortex showed the same degree of synchrony as in younger ones.

Accuracy in the treated older adults wasn’t dipping after 50 minutes, Reinhart said: “My guess is that [the effect] lasts more than 50 minutes, and potentially a few hours.”

The idea that brain-wave synchronization underlies working memory goes back at least 20 years, with many labs finding evidence that oscillations of specific frequencies are necessary for working memory. “Populations of cells that synchronize their activity are believed to be transferring information,” Reinhart said — for working memory, from the temporal regions to the prefrontal cortex.

After alternating current kicks brain waves from the prefrontal cortex and temporal lobes into synchrony (about eight cycles per second worked pretty well), “those two areas are talking to one another,” he said. “We’re resynchronizing these brain regions.”

Other labs have also shown that electrical stimulation of the brain can improve memory. In a 2018 study, current from electrodes implanted in the brains of people with epilepsy improved memory by 15%. And research funded by the Pentagon’s Defense Advanced Research Projects Agency reported last year that a “human memory prosthesis”— electrodes implanted in the hippocampus — improved both short-term memory (similar to working memory) and long-term memory by up to 35% or so in eight people with epilepsy.

This is definitely a “don’t try this at home” experiment. Additional research will be needed to determine whether alternating-current stimulation can improve working memory in a durable way, how often it would have to be given, what targets and AC frequency are optimal, and whether the artificial lab task translates into real-world benefits. “I would not rule out [durable improvement] completely,” said Göttingen’s Nitsche. “Advanced stimulation protocols might result in longer-lasting effects, and work has to be conducted to identify optimized protocols” — and test their safety.

The worse the memory of the older people in Reinhart’s study, the more that alternating-current stimulation improved it. But even in younger adults with good memory, “we are seeing boosts in brain and behavior measures,” he said about unpublished results. “I think it is possible to turbocharge” their memory, too.

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  • Awareness is the greatest and most advanced teacher on our planet, but it does not come with identifying labels of scientific and medical terminologies, therefore this knowledge can only be shared by calling a spade a spade.

    The brilliance found within our brain, can aid us with our searches by jumping from left to center, the transition is very smooth, it reminds me of a train changing tracks.

  • Electromagnetic fields are in each and every human system, without them there simply could be no life, this clearly is based upon the natural design, dating back to creation, but the question should be, why do some systems create more electricity than others. The answer can be found in region of birthplace, as well as genetics of course. We know, that many diseases vary from region to region. It is vital to understand, that our internal circuitry’s can overheat do to overload, which in turn can lead to burn out, creating a black hole, which than will release toxins into the system, setting off chain reactions, which will be medically unknown and unheard of.
    Thankfully, the intelligence found within the brain, knows how to repair damaged or burned out coils, by creating new ones, usually three at a time, to hang in suspension until ready to be fired through the back of the brain.
    Depending on the magnitude of damage, repairs can take many years, do to the precise process.

    • Ursula – “Repairs,” recalibrations, optimizations occur within moments at times in neurofeedback training where the CNS is given information about its own emerging EEG activity through which it self-corrects in evolutionarily significant ways. Here is a study on the amelioration of unremitting chemotherapy induced cognitive decline:

      https://journals.sagepub.com/doi/full/10.1177/1534735413477192

  • I smile sadly when I hear people speak of “energy” which should never, ever be confused with “electricity”
    Food gives us energy, it is like the gasoline in our car, but the human engine consist’s of strings and coils.
    The strings are comparable to the musical instrument called the Harp.
    Strings vibrate, create sound and consequently echo’s.
    Coils spin and pull, these cycles are precisely two minutes long.
    If, do to obstructions and or magnetism, these two powerful sources collide, massive internal electric shocks, after shocks, tremors and vibration will occur.

  • Electricity does much more than just increase memory, because the left side of brain is not linked to time as we understand time, therefore memory can take us back to ancient times, accompanied by visual imagery of words, numbers, ancient symbols etc, but electricity also has phenomenal affects on our emotions which are linked to the color yellow as it relates to our brain map. High amounts of electricity are based upon speed and spinning, which unfortunately can be created by our own system, triggered by injury/surgery, which can cause shifting, do to obstructions. High amounts of electricity within the system, will affect all brain dimensions and there are many.

  • Hi very interesting i lost abt 5 years of memory abt 5 years ago, beiing an electrician man i would like to kno the AC level voltage and the frequency
    used thanks for replay…

  • Short term memory loss with Parkinson’s represents the loss of the neurotransmitter, dopamine. Is there any evidence that A/C treatment enhances the release or synthesis of more dopamine from damaged neurons?

  • According to the following article, different placebos (color, smell, etc.) can be good for treating different conditions:
    The Placebo Effect, Digested – 10 Amazing Findings; written by Christian Jarrett, published in the BPS Research Digest.

    So, I think zapping which can be ‘felt’ as pecking of the scalp is a better ‘placebo’ than the control cognition that was provided in this experiment (zapping may have nothing to do with the electrical stimulation involved).

  • Intriguing, but without reading original study, too many unanswered questions to get a sense of what is actually going on. Wish this article had gone into some more detail about how the study was conducted. A quote from someone that the study was well-designed doesn’t mean much, really. I have seen this kind of quote before, but on examining the study it referred to, I wondered if the speaker had really given much thought to it. As it is, I wonder if the circumstances in which the study was done could have introduced the “novelty factor” that can stimulate more focused attention on tasks, thus improving performance? No way to tell from this. Heaven knows, there is a fascination with passing electrical current through the human brain that goes back. It certainly does something, and it looks like we’re trying to figure out just what.

  • Can this treatment be done in the United Kingdom or is it only in Boston.
    I know someone who is younger who could do well if the treatment works.

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