‘Transcranial random noise stimulation’ — a non-invasive technique that involves delivering weak electrical currents to the brain via electrodes placed on the scalp — is being studied for how it can impact brain activity, such as improving cognition, depressive symptoms and reducing pain.
Seventy-two adults took part in a five-day maths training programme — 24 received transcranial random noise stimulation to the dorsolateral prefrontal cortex, 24 to the posterior parietal cortex, and 24 received a sham version of the treatment (placebo).
The posterior parietal cortex, which helps process information received via one’s senses, is located in the parietal lobe at the top rear of the head.
Brain scans revealed that people with a stronger connection between the dorsolateral prefrontal cortex (which helps focus and learn) and the posterior parietal cortex performed better in mathematical tasks.
However, for those having a weak connection between these brain regions, providing safe electric currents to the dorsolateral prefrontal cortex significantly improved learning, the researchers said.
Improvements were also related to lower levels of GABA in the dorsolateral prefrontal cortex.
GABA is a brain chemical that works to stabilise newly acquired information and is, therefore, crucial to learning and memory.
“By integrating insights from psychology, neuroscience and education to develop innovative techniques that address neurobiological constraints, we can help more people reach their potential, broaden access to diverse career pathways and reduce long-term inequalities in income, health and wellbeing,” Kadosh said.
The team emphasised that while previous studies have highlighted the role of brain regions — dorsolateral prefrontal cortex and posterior parietal cortex — in mathematical learning, their study sheds light on how these regions play a causal role in a critical academic skill.
“Our multimodal approach elucidates the causal role of the (dorsolateral prefrontal cortex) and frontoparietal network in a critical academic learning skill,” the authors wrote.