Clinical Implication of Auditory Evoked Potential Related with Sensitivity and Impulsivity

The loudness dependence of the auditory evoked potential [LDAEP] is a measure of brain sensitivity and a potential biological marker of central serotonergic activity. Serotonin was also known to be related with impulsivity. Hence, LDAEP may be useful to evaluate a relationship between sensory sensitivity and impulsivity. As has been reported, LDAEP is related to depression, anxiety and mood lability in clinical samples as well as healthy participants, because patients with high emotional sensitivity often report somatosensory sensitivity, and show higher sensory arousal responses, reflected by LDAEP. Certain clinical populations may also show deviant LDAEPs modulated by pathological impulsivity traits. Clinical populations with abnormal impulsivity often show faster reaction times for motor responses and elevated false alarm rates in a response inhibition task, and likely represent an abnormal serotonergic expression. Hence, LDAEP appears to be a marker of impulsivity with the changes of inhibitory behavioral properties. Functional neuroimaging studies additionally support our arguments, because impulsivity-related inhibition performances are associated with activation of prefrontal cortex, one of representative areas for a serotonergic system. In summary, LDAEP may significantly function as a promising biological marker for reflecting sensitivity and impulsivity in not only clinical but also general populations.