Impairments in intentional—but not unintentional—inhibition have been found in schizophrenia, and are thought to contribute to the presence of psychotic symptoms. However, it was previously unknown whether this intentional cognitive control impairment extends to intentional resistance to interference—another form of cognitive control. The current study resolved this issue through administering two cognitive control measures: one with a high intentional resistance to interference demand and the other with a high unintentional inhibition demand, to schizophrenia (n = 61) and healthy control (n = 34) participants. Consistent with previous findings, schizophrenia participants’ performance on the measures with a high unintentional inhibition demand was intact; however, they were impaired on the task with high intentional resistance to interference demands compared with controls. This latter finding suggests that intentional cognitive control impairments previously found in schizophrenia are not specific to inhibition, but instead are more general, including both processes requiring inhibition (as consistently reported in the literature) and resistance to interference (as found in the current study). (JINS, 2009, 15, 982–989.)

Decision making in an emotionally conflicting situation is important in social life. We aimed to address the similarity and disparity of neural correlates involved in processing ambivalent stimuli in patients with schizophrenia and patients with depression. Behavioral task-related hemodynamic responses were measured using [15O]H2O positron emission tomography (PET) in 12 patients with schizophrenia and 12 patients with depression. The task was a modified word-stem completion task, which was designed to evoke ambivalence in forced and non-forced choice conditions. The prefrontal cortex and the cerebellum were found to show increased activity in the healthy control group. In the schizophrenia group, activity in these two regions was negligible. In the depression group, the pattern of activity was altered and a functional compensatory recruitment of the inferior parietal regions was suggested. The prefrontal cortex seems to be associated with the cognitive control to resolve the conflict toward the ambivalent stimuli, whereas the cerebellum reflects the sustained working memory to search for compromise alternatives. The deficit of cerebellar activation in the schizophrenia group might underlie the inability to search and consider compromising responses for conflict resolution. (JINS, 2009, 15, 990–1001.)

Cognitive and affective complaints are common in patients with primary hyperparathyroidism (PHPT), but few studies have used psychometric testing to document these symptoms and their response to parathyroidectomy. The current study sought to clarify the nature of cognitive and affective impairments in PHPT and changes postparathyroidectomy. One hundred eleven patients with PHPT underwent neuropsychological evaluation prior to parathyroidectomy with 68 returning for an early postsurgical evaluation. Changes in cognition were assessed using practice effect corrected reliable change indices. Biochemical and anesthesia variables were compared between groups who improved and declined. In a subset of patients, assessment revealed a significant pattern of cognitive slowing, reductions in psychomotor speed, memory impairment, and depression prior to parathyroidectomy. Postsurgical evaluations revealed a trend for improvements on timed tests and depression but a decline in memory. Older patients responded less well to surgical intervention, as did patients who experienced more dramatic changes in biochemical status following surgery. Cognitive changes early postparathyroidectomy are characterized by improved information processing speed and decline in verbal memory, with younger patients more likely to recover during this acute phase. The need for longer-term follow-up studies and increasing utilization of neuropsychological assessments in this population are discussed. (JINS, 2009, 15, 1002–1011.)