Studying the Effects of Different Inter-Stimulus-Intervals in ADHD Adults While Performing CPT

Abstract

Event-related potentials were investigated in this study while participants were performing a continuous performance task (CPT). A 21 electrode EEG signal was recorded in a 10-20 standard system from 50 healthy and ADHD adult subjects. After the basic pre-processing steps (band-pass and notch filtering, re-referencing and baseline rejection) Independent component analysis (ICA) was used to diminish the remaining EOG artifact. Then, event-related potentials were calculated using the time locked epochs of the cleaned signal. Afterwards, P300 morphological features such as peak amplitude and latency, were extracted and then the statistical process was carried out, to determine if the peak amplitudes and latencies have significant difference among healthy and ADHD subjects and in different inter-stimulus-intervals (ISIs). Our results show that as ISI gets longer, the difference in P300 latency between ADHD and healthy subjects gets bolder, statistical analysis and p-value confirm these results. Also, further statistic analysis is performed to figure out the effect of ISI variations in latency and peak amplitude of P300 in every subject; longer ISI leads to an increase in the latency of P300 in ADHD subjects.