How brain purposefully ignores distractions

A study has revealed that our brain purposefully ignores less important things for us to concentrate on something more crucial.

"This is about the mechanisms the brain is using to block out distracting things in the environment," said Stephanie Jones, assistant professor of neuroscience at Brown University.

The new findings came from brain scans of 12 volunteers who were told they would feel a brief tap on the left middle finger or the left big toe.

In some cases they were then told to report only stimuli felt on the foot and to disregard what they might feel on their hand.

In other cases, they were told to attend to or report sensations only in the hand and to ignore those in the foot.

The researchers measured the power and timing of different brain wave frequencies in various brain regions.

They were particularly interested in brainwave synchronisation between the part of the somatosensory cortex that processes touch in the hand and the right inferior frontal cortex (rIFC), a part of the brain known to govern suppression of attention and action.

The researchers found significant patterns of synchrony between regions.

In particular, looking at the synchrony between the somatosensory cortex's hand region and the rIFC, they saw significant increases when people were told to attend to only sensations in the foot compared to when they were told to attend to sensations only in the hand.

The team has already seen that people can learn -- through mindfulness meditation, for instance - to manipulate their alpha rhythms in the somatosensory cortex as they switch their attentional focus.

The new results extend that work by laying out how alpha and beta rhythms appear to connect the somatosensory cortex to the frontal cortex to coordinate the multistep process of taking attention away from, and then ignoring, a sensory stimulus.

"We are linking different ways of looking at the brain that do not usually come into dialogue with one another," the authors added.

The study was published in the Journal of Neuroscience.