Test-retest reliability of ERP components: A short-term replication of a visual Go/NoGo task in ADHD subjects

Event-related potentials (ERPs) have been widely used to investigate brain functioning in children with Attention Deficit Hyperactivity Disorder (ADHD) in both research and diagnostic settings. To ensure the efficiency of ERP techniques in ADHD diagnosis and in longitudinal observational studies, the test-retest reliability of the affected population must be validated. Thus, the present article assesses the short-term test-retest reliability of certain early and late ERPs (i.e., P1, N1, N2, P2, P3), as well as independent components (ICs) decomposed from the above mentioned ERPs (IC P3 Go, IC P3 NoGo early, IC P3 NoGo late) relevant to ADHD, through the Intraclass Correlation Coefficient (ICC). More specifically, we employ a cued visual Go/NoGo paradigm for recording ERPs from 22 children with ADHD (mean age 12.2), twice within 30 min. Amplitudes and latencies are calculated by the 'peak amplitude' method and by a variation of the fractional area. Results for amplitudes lie mostly within the 'good' and 'excellent' range for both measurement methods, while ICC for latencies is more variable ranging from 'poor' to 'excellent' results. Crucially, the ICs, which are associated with distinct functionally independent processes of the executive attentional system have shown a comparable test-retest reliability with the raw ERPs. Our results are consistent with other reliability studies of neurotypical population in the literature, and as such, consist initial evidence that ERPs could be reliable neurophysiological markers for the ADHD population.