White matter density (VIDEO) University of Iowa Health Care This video is under embargo. Please login to access this video. Caption This video is a map of edge density, a measure of the density of white matter connections between different brain regions. The color scale goes from dark purple where there are only sparse connections, to a yellowish white where the connections are most densely packed. A University of Iowa study suggest that damage to highly connected regions of white matter is more predictive of cognitive impairment than damage to highly connected gray matter hubs. Credit Justin Reber, University of Iowa Usage Restrictions Image may be used for educational or informational purposes only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.