'Too Much Brain' May Be the Cause of Your Easy Distraction

by Tanya Thomas on May 10 2011 7:29 AM

A new study by the scientists at the University College London has found that people who are easily distracted may have 'too much brain'. Why? Because there are larger than average volumes of grey matter in certain brain regions of people whose attention is readily diverted.
Ryota Kanai and his colleagues arrived at this conclusion after comparing the brain activity in both easy and difficult-to-distract individuals.

Each individual was quizzed about various attention-orientated activities they perform -like how often do they notice traffic signs or if they ever get sidetracked to the extent they forget why they're in a particular location or the goal of a particular activity.

The most distracted individuals received the highest score.

The researchers observed that there was a significant difference in grey matter levels between individuals scoring high (easily distracted) and those scoring low in a region of the brain known as the left superior parietal lobe (SPL).

They found that easily distracted people had more grey matter in that region.

To prove whether the left SPL gray matter levels have a major role to play in attention deficit, the researchers turned to transcranial magnetic stimulation or brain damping.

Fifteen volunteers had the activity of the SPL part of their brains dampened with a magnet for around half an hour, after they were asked to perform a timed task both with and without a distraction.

The difference in the time taken to perform the tasks is a measure of how easily distracted a person is, New Scientist quoted Kanai as saying.

When the same individuals later repeated the exercise following transcranial magnetic stimulation over the left SPL to dampen its activity, the time each took to complete the task increased by around a quarter, on average.

"This suggests that the left SPL is involved in top-down control of attention," said Kanai.

The two experiments suggest that the left SPL works to overcome distraction, and that those with larger left SPLs are more easily distracted.