Multicenter P300 brain mapping of impaired attention to cues in hyperkinetic children

OBJECTIVE: To measure specific neurophysiological attention deficits in children with hyperkinetic disorders (HD; the ICD-10 diagnosis for severe and pervasive attention-deficit/hyperactivity disorder [ADHD]). METHOD: In a multicenter sample of 148 children with HD and control children aged 8 to 14 years, event-related potential maps were recorded during a cued continuous performance test (A-X/O-X). Maps to cues (requiring attention but no response) and distractors and performance were tested for differences between age- and sex-matched HD and control groups (n = 57 each), as well as between clinics (n = 5). RESULTS: The N1, P3a, and P3b maps revealed reliable attention effects, with larger amplitudes after cues than after distractors, and only minor differences across clinics. Children with HD missed more targets, made more false alarms, and had larger N1 followed by smaller P3b amplitudes after cues than did controls. Cue-P3b amplitude correlated with detecting subsequent targets. Cue-P3b tomography indicated posterior sources that were attenuated in children with HD. CONCLUSIONS: Brain mapping indicates that children with HD attend to cues (preceding potential targets) with increased initial orienting (N1) followed by insufficient resource allocation (P3b). These multiple, condition-specific attention deficits in HD within 300 msec extend previous results on ADHD and underline the importance of high temporal resolution in mapping severe attention deficits.