Visual inspection time as an accessible measure of processing speed: A validation study in children with cerebral palsy

Objective: This study examined the validity of a visual inspection time (IT) task as a measure of processing speed (PS) in a sample of children with and without cerebral palsy (CP). IT tasks measure visualization speed without focusing on the motor response time to indicate decision making about the properties of those stimuli.

Methods: Participants were 113 children ages 8-16, including 45 with congenital CP, and 68 typically developing peers. Measures were a standard visual IT task that required dual key responding and a modified version using an assistive technology button with response option scanning. Performance on these measures was examined against traditional Wechsler PS measures (Coding, Symbol Search).

Results: IT performance shared considerable variance with traditional paper-pencil PS measures for the group with CP, but not necessarily in the typically developing group. Concurrent validity was found for both IT task versions with traditional PS measures in the group with CP. IT classification accuracy for lowered PS showed modest sensitivity and good specificity particularly for the modified IT task.

Conclusions: As measures of PS in children with CP who are unable to validly participate in traditional PS tasks, IT tasks demonstrate adequate concurrent validity and may serve as a beneficial alternative measure of PS in this population.