All willing family members were administered the CPT. The CPT and associated measurements have been previously described in detail (Conners and MHS Staff, 2000). Participants completed the CPT on a desktop computer in a room with minimal distractions. Three hundred and sixty letters appeared on the screen for roughly 14 min and participants were instructed to press the spacebar whenever a target letter (non-‘X’) appeared on the screen. Five measurements from the CPT were used for our analysis (Table 1). Descriptions on how to interpret these measurements are also provided in Table 1.
