Usually, the mean normalized intensity in aseg.stats is not considered important. However, by mistake, I put it in my analysis and found out that the mean intensity of the thalamus explains a lot the variance of my data. 

What could be the physiological meaning of higher intensity in the thalamus? Could it be associated with either increased myelinization ( more axons or synapses) or with decreased neural soma? Has anybody reported mean normalized intensity effects in subcortical structures?

Thanks

Dorothy