A comparison of visual inspection time measures in children with cerebral palsy

This study examined the performance of children with and without cerebral palsy on two inspection time (IT) tests, as accessible nonspeeded response measures of cognitive processing speed.

Participants, ages 8 to 16, included 66 children with congenital CP and 119 typically developing peers. Measures were two visual IT tasks with identical target stimuli but differential response strategies either via a traditional dual-key method or with an assistive technology pressure switch interface and response option scanning.

The CP group had slower IT than the control group independent of test version. Log transformations were used to address skew, and transformed mean intraclass correlations showed moderate agreement between test versions for both participant groups. Bland-Altman plots showed that at higher mean IT thresholds, greater discrepancies between test version scores were observed.

Findings support the feasibility of developing tests that reduce speeded motor response demands. Future test development should incorporate increased gradations of difficulty at the extremes of neuropsychological functioning to more accurately assess the performance of individuals whose conditions are associated with atypical performance levels.