Assessment of cortical inhibition in adult attention-deficit/hyperactivity disorder by paired-chirp auditory evoked potentials

In order to further research cortical impairment in ADHD patients, late auditory evoked potentials were measured. By using paired-chirp auditory late responses, we compared the ADHD group against a control group, focusing on the inhibition elicited by the stimuli. The results show overall smaller amplitudes in the N100 and P200 waves, as well as a reduced inhibition in test chirp for ADHD patients. A frequency study using the wavelet phase synchronization stability transform was made in order to strengthen the results, as well as analysis of variance test for frequency and reproducibility index for amplitude. Both amplitude and frequency show there is an impaired auditory inhibition in ADHD patients, for interstimulus intervals of 500 and 700 ms, and reinforce the knowledge that impairments in this condition are present in multiple cortical areas.