Neurophysiological indices of self-monitoring were assessed in a group of patients with Schizotypal Personality Disorder (SPD) and a control group. Both groups were assessed after the administration of risperidone and placebo.

The electroencephalogram (EEG) was recorder while participants (SPD participants and controls) performed a behavioral task: the Eriksen Flanker Task. The continuous EEG was segmented, corrected for artifacts and averaged. A component of the event-related brain potential known as the error-related negativity (ERN) was identified and its amplitude quantified in microvolts.

This procedure was conducted two hours after the administration of risperidone 1 mg and placebo (lactose) on two different experimental days and for each participant group (SPD patients and controls).

The amplitude of the ERN after placebo was compared between groups to test for baseline (non-drug-induced) differences between patients and controls.

The impact of risperidone on the amplitude of the ERN was compared between the two participant groups.

Inclusion Criteria:

• Schizotypal Personality Disorder

Exclusion Criteria:

• Major Psychiatric Disorder
• Medical condition