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Distractibility May Be Caused By Excess Grey Matter

A model showing human brain-cell action is lighted by fiber optics; photo by John Schneeberger and Larry Kinney

Being called a brainiac may be a compliment but when it comes to gray matter, a person can have too much of a good thing.  Scientists at University College London recently conducted a study that links high levels of distractibility with an increased volume of grey matter in the brain’s left superior parietal lobe.

The reasons for this are not yet fully understood, but it might have something to do with the way the brain pares away excess neurons as it matures in order to more effectively carry out certain tasks.  The brains of adults who suffer from attention deficit disorder may have failed to complete this process, and the connection may also help explain why children tend to be more easily distracted.

The results of the study appear in this week’s issue of The Journal of Neuroscience.

For more of the latest science news, check out the National Geographic Library’s twice-weekly news rundown, Earth Current.


  1. VideoPortal
    March 10, 3:28 pm

    Quite why SPL size works this way is unclear, but Kanai speculates that it may be linked to that fact that as we mature, the brain s grey matter is pruned of neurons in order to work more efficiently.

  2. David Braun
    May 10, 2011, 8:39 pm

    Too much of a good thing!