Natural brain state is primed to learn

STUDYING for an exam? Begin by thinking your way into a learning state.

                             

Until now, neuroscientists have focused on identifying parts of the brain that are active during learning. "But no one has looked at the preparedness state," says John Gabrieli at the Massachusetts Institute of Technology. "The idea is to identify before the event whether the brain is prepared to be a learner."

Gabrieli and his colleagues used functional MRI scanning to monitor the naturally fluctuating brain activity of 20 volunteers and investigate whether the brain enters such a learning state. While in the scanner, each person was presented with 250 images, one at a time, and asked to memorise them. The volunteers were shown the images again 2 hours later - mixed in with 250 new ones - and asked to remember which they had seen before.

Looking through the results, the team was surprised to find that in the moments before individuals were shown images that they later remembered, they had low levels of activity in the parahippocampal place area - a region of the brain that is known to be highly active during learning. "Maybe the fact that this region was less active meant that the deck was cleared - that it was more open for a stimulus to provoke a response," suggests Gabrieli.

To investigate further, the team attempted to boost subsequent participants' memory test scores by presenting them with images only when they showed this pattern of brain activity. "There was around a 30 per cent improvement in the memory task," Gabrieli says (NeuroImage, DOI: 10.1016/j.neuroimage.2011.07.063).

The MIT team is now working on a way to monitor this "preparedness to learn" using electroencephalography (EEG) - a more portable and much cheaper brain-monitoring technique. Gabrieli's idea is to make learning more efficient by selectively teaching the prepared brain. "You could imagine a computer-based learning system which would stop when the brain is not prepared to learn and restart when it is," he says.

Leonardo Cohen, at the US National Institutes of Health in Bethesda, Maryland, who was not involved in the study, thinks the next step should instead be to use the existing scanning method to train individuals to enter good brain states of their own accord, by rewarding them when they do. "Optimising these brain regions would provide a more sophisticated way of approaching a learning task," says Cohen. "It's a very exciting idea."

A third approach would be to find a way of stimulating the same pattern in a person's brain. It has already been shown that brain stimulation using electric currents can boost a number of cognitive functions (see "Apply the electrodes..."). Could it help make us better learners, too?

"Combining brain stimulation with Gabrieli's approach could take performance to the next level," says Cohen. He suggests training an individual once they have entered the preparedness state, and then stimulating areas of the brain known to be involved in memory consolidation to cement the learning process: perhaps the ultimate in brain optimisation.

Apply the electrodes...

Externally modulating the brain's activity can boost its performance.

The easiest way to manipulate the brain is through transcranial direct current stimulation (tDCS), which involves applying electrodes directly to the head to influence neuron activity with an electric current.

Roi Cohen Kadosh's team at the University of Oxford showed last year that targeting tDCS at the brain's right parietal lobe can boost a person's arithmetic ability - the effects were still apparent six months after the tDCS session.

More recently, Richard Chi and Allan Snyder at the University of Sydney, Australia, demonstrated that tDCS can improve a person's insight. The pair applied tDCS to volunteers' anterior frontal lobes - regions known to play a role in how we perceive the world - and found the participants were three times as likely as normal to complete a problem-solving task.

Brain stimulation can also boost a person's learning abilities, according to Agnes Flöel's team at the University of Münster in Germany. Twenty minutes of tDCS to a part of the brain called the left perisylvian area was enough to speed up and improve language learning in a group of 19 volunteers (Journal of Cognitive Neuroscience, DOI: 10.1162/jocn.2008.20098).

Using the same technique to stimulate the brain's motor cortex, meanwhile, can enhance a person's ability to learn a movement-based skill (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0805413106).