Convergent validity of executive organization measures on cancellation

Cancellation tests have traditionally been used to measure visuospatial neglect. Recently, such tests have also been viewed as potential measures of executive function. Mark and colleagues (2004; Disorganized search on cancellation is not a consequence of neglect. Neurology, 63, 78-84) developed three objective measures of organization based on reconstructing target-marking pathways from one form of a cancellation test: mean inter-target distance, path intersection rate, and a quantification of overall path uniformity (i.e., predominantly radial versus horizontal cancellation progress) that they termed "best r". However, the validity of these measures with respect to a subjective judgment of organization was not assessed. In the present study, 50 observers rated the overall organization of 50 reconstructed pathways from stroke patients and non-brain-injured adults to allow evaluating the convergent validity of the three proposed executive organization measures. Inter-target distance (r = .86), intersection rate (r = .87), and best r (r = -.69) were all found to be highly correlated with observer ratings. These results indicate good convergent validity for all three executive organization measures on a form of the cancellation test.