Negative priming within a Stroop task in children and adolescents with attention-deficit hyperactivity disorder, their siblings and independent controls
Objective <br> Negative priming (NP) is the slowed response to a stimulus that was previously ignored. Response times in NP task conditions were compared with the interference provided by congruent/incongruent stimuli in a Stroop condition in the same task in children diagnosed with attention-deficit hyperactivity disorder (ADHD), their unaffected siblings, and independent controls. <br> <br> Method <br> Speed, accuracy, and variability of responses were compared using a computerized NP Stroop test for 35 children with ADHD, 24 siblings without diagnosis, and 37 independent healthy controls aged 6 to 17 years. <br> <br> Results <br> NP was evident at test onset for congruent trials in children without a diagnosis and was reduced initially in those with ADHD occurring in the absence of a significant Stroop interference effect and independently of age or symptom severity. Incongruency masked NP effects. Cases showed more intra-individual response-time variability. <br> <br> Conclusions <br> Both NP in normal children and its reduction in ADHD cases attenuated across trials reflecting the increased facilitation from previous stimulation.