Bivariate correlations between biographical, cognitive and white matter variables.

<p>*P&lt;.05,</p><p>**p&lt;.01.</p><p>ISD  =  Intraindividual variability; SRT  =  Simple RT; CRT  =  Choice RT; ICV  =  Intracranial volume; WMH  =  white matter hyperintensities (ICV and WMH  =  mm<sup>3</sup>); Gender, 1 = male, 2 = female.</p>