Table 1 details the demographic and clinical variables, DSM-IV (28) criteria, and medication status for the two patient subgroups and healthy controls (HC) in the two memory paradigms. Most patients (14 AH, 30 NH) and 42 healthy adults provided data for both memory paradigms. Although the groups did not differ in gender, age (range 18–56 years) or degree of right-handedness (laterality quotient range 20–100), patients had significantly less education than controls. However, the available verbal IQ data (WAIS) suggested that the patients’ verbal skills were well within normal range and did not differ between AH and NH subgroups. Although hallucinators and nonhallucinators did not differ in age of onset (range 9–37 years) or illness duration (range 0–47 years), the total score of the brief psychiatric rating scale (BPRS), which was derived from the Positive and Negative Syndrome Scale (PANSS; Kay, Opler, & Fishbein, 1992), indicated that hallucinators were more disturbed than nonhallucinators. This difference is also reflected in higher positive and negative PANSS subscales in hallucinators than nonhallucinators. Notwithstanding, all electrophysiologic findings reported were not affected by subgroup differences in total BPRS measures of severity (see below).
