Neuropsychological functioning in schizophrenia patients with first-rank (passivity) symptoms

In this study, we conducted a broad investigation of neuropsychological functioning in schizophrenia patients with first-rank (passivity) symptoms (FRS) using standardized cognitive tests. We focused on 3 neuropsychological domains, partly informed by 3 broad hypotheses concerning the pathogenesis of FRS. We tested predictions that patients with FRS would show: (i) memory deficits consistent with abnormalities in medial temporal lobe functioning; (ii) reduced cerebral lateralization on tasks of motor and language functions, and (iii) deficits on tasks of executive functions as a measure of the integrity of the prefrontal cortex for supporting self-monitoring processes.

In 2 parallel studies, we administered a range of neuropsychological tests to patients with FRS (sample A = 17, sample B = 15) and without FRS (sample A = 28, sample B = 20) and to healthy controls (sample A = 109, sample B = 22).

The results showed reduced cerebral lateralization in patients with FRS, but there were no memory deficits or executive dysfunctions relative to patients without FRS. An unexpected finding was that, on many cognitive tasks, the performance of the patients with FRS was relatively spared compared to that of the patients without FRS. These results could not be accounted for by demographic features or medication effects.

Our results provide qualified support for the reduced lateralization hypothesis. Analyses of performance across neuropsychological domains showed that generalized deficit is not a sufficient explanation for the occurrence of FRS.