Measure of sustained attention and impulsiveness control in children:: New way of administering the Faces, Differences Perception Test

The Differences Perception Test (DPT) is a classical paper-and pencil check-off task. In this study on schoolchildren, the testing period was extended to 6 minutes in order to measure sustained attention -number of correct answers (C)- and impulse control-inversely related to number of errors (E). The formula used to calculate the Impulse Control Index (ICI) was ICI = C-E / C+E. Our normative sample consisted of 1090 children (72% males) stratified for ages between 6 and 10 years, and randomly recruited from local schools. The test was also given to a clinical series of 66 consecutive patients within the same age range, of which 36 had been diagnoses with attention deficit hyperactivity disorder (ADHD) and 30 with reading disability (RD) according to DSM-IV / CIE-10 criteria. All participants had an intelligence quotient > 85. Normative data of evaluated variables (correct answers and ICI) in the school sample population are provided. The clinical group's performance as a whole was worse than that of the normative sample in both correct answers and ICI variables (ANOVA: p < 0.01). Furthermore, children with ADHD had a lower ICI than the RD group (t-Student test: p < 0.01). The ICI showed good discriminative power: 64% of participants with ADHD diagnosis had an ICI lower than -1.5 s -the incidence in the normative sample is only 3%. These results support the existence of an important inhibitory control deficit in ADHD. Thus, DPT employed in this way may have a complementary use in identifying children with ADHD.