Electrical brain stimulation boosts memory and maths in separate studies

Two new studies show that mild electrical stimulation can enhance cognitive performance. US researchers found that transcranial alternating current stimulation (tACS) improved memory recall in older adults, while UK scientists reported that transcranial random noise stimulation boosted maths scores in low-performing students. The findings revive debate about the potential and pitfalls of brain-zapping wearables.

Bottom line — Two studies show electrical brain stimulation can boost memory and maths, but ethical concerns over access remain.

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• The memory study, published in Nature Neuroscience, involved 150 volunteers aged 65–88 who received 18–20 minutes of tACS during a single session, per The Scientist. Those who received real stimulation recalled more words from a list of 30 than those who got sham stimulation.
• The maths study, published in PLOS Biology, recruited 72 University of Oxford students. Low performers saw their scores jump by 25–29% after receiving transcranial random noise stimulation via electrode-fitted caps, according to ScienceAlert.
• Lead researcher Roi Cohen Kadosh of the University of Surrey said the stimulation helped underperformers reach or surpass peers with naturally stronger brain wiring, but those who already performed well saw no benefit.
• Cohen Kadosh flagged an ethical concern: the risk that such technologies could become more available to those with financial means, widening access gaps. He also urged the public not to try this at home.
• Siyar Bahadir at The Feinstein Institutes in New York, who was not involved in the memory study, told New Scientist that if benefits hold up, the technique could be suitable for a wearable device and accessible to many more people.
• The memory study used tACS, which transmits a mild electrical current through the brain via scalp electrodes, to improve signalling between cells in the hippocampus, per The Scientist and WSJ.
• The maths study used transcranial random noise stimulation, which enhances neuronal excitability and interacts with the brain chemical GABA, compensating for weak neural connectivity, per ScienceAlert.

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