London: Scientists have shown for the first time that briefly tuning into a person's individual brainwave cycle before they perform a learning task dramatically boosts the speed at which cognitive skills improve, according to a study. According to the team behind the study, calibrating rates of information delivery to match the natural tempo of our brains increases our capacity to absorb and adapt to new information.
The researchers from University of Cambridge, UK, say that these techniques could help us retain "neuroplasticity" much later in life and advance lifelong learning. "Each brain has its own natural rhythm, generated by the oscillation of neurons working together," said Prof Zoe Kourtzi, senior author of the study, University of Cambridge. "We simulated these fluctuations so the brain is in tune with itself - and in the best state to flourish," said Kourtzi.
"Our brain's plasticity is the ability to restructure and learn new things, continually building on previous patterns of neuronal interactions. By harnessing brainwave rhythms, it may be possible to enhance flexible learning across the lifespan, from infancy to older adulthood," Kourtzi said. The findings are published in the journal Cerebral Cortex.
The neuroscientists used Electroencephalography - or EEG - sensors attached to the head to measure electrical activity in the brain of 80 study participants, and sample brainwave rhythms, the study said. According to the study, the team took alpha waves readings. The mid-range of the brainwave spectrum, this wave frequency tends to dominate when we are awake and relaxed.
Alpha waves oscillate between eight to twelve hertz: a full cycle every 85-125 milliseconds. However, every person has their own peak alpha frequency within that range, the study said. Scientists used these readings to create an optical "pulse": a white square flickering on a dark background at the same tempo as each person's individual alpha wave, the study said.
According to the study, participants got a 1.5-second dose of personalised pulse to set their brain working at its natural rhythm - a technique called entrainment - before being presented with a tricky quick-fire cognitive task: trying to identify specific shapes within a barrage of visual clutter. A brainwave cycle consists of a peak and trough.
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Some participants received pulses matching the peak of their waves, some the trough, while some got rhythms that were either random or at the wrong rate, a little faster or slower, the study said. Each participant repeated over 800 variations of the cognitive task, and the neuroscientists measured how quickly people improved, the study said.
The study found that the learning rate for those locked into the right rhythm was at least three times faster than for all the other groups, it said. The study also found that when participants returned the next day to complete another round of tasks, those who learned much faster under entrainment had maintained their higher performance level, it said.
"It was exciting to uncover the specific conditions you need to get this impressive boost in learning," said first author Dr Elizabeth Michael, University of Cambridge. "The intervention itself is very simple, just a brief flicker on a screen, but when we hit the right frequency plus the right phase alignment, it seems to have a strong and lasting effect," said Michael.
Entrainment pulses need to chime with the trough of a brainwave. Scientists believe this is the point in a cycle when neurons are in a state of "high receptivity", the study said. "We feel as if we constantly attend to the world, but in fact our brains take rapid snapshots and then our neurons communicate with each other to string the information together," said co-author Victoria Leong, from Nanyang Technological University, Singapore and Cambridge's Department of Paediatrics.
"Our hypothesis is that by matching information delivery to the optimal phase of a brainwave, we maximise information capture because this is when our neurons are at the height of excitability," said Leong. "When adults speak to young children they adopt child-directed speech - a slow and exaggerated form of speaking. This study suggests that child-directed speech may be a spontaneous way of rate-matching and entraining the slower brainwaves of children to support learning," said Leong. (PTI)
