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Objectives. Anhedonia in schizophrenia results from a deficit in anticipatory pleasure rather than consummatory pleasure. This study aimed to determine the neural basis of the predictive and experiential components of anticipatory pleasure in schizophrenia. Methods. A hedonic rating task was performed by 15 patients with schizophrenia and 17 controls while undergoing functional magnetic resonance imaging. Participants evaluated the level of pleasantness for the preview/predictive phase, comprising a narration and adjunctive audiovisual stimuli for pleasurable experience, and the subsequent viewing/experiential phase, comprising a video clip for a pleasant event. Results. A significant group-by-phase interaction was seen in the rostral anterior cingulate cortex (ACC) and caudate, resulting from reduced activations in patients during the preview phase. Patients showed significantly reduced activation in the frontopolar cortex and rostral ACC during the preview phase. The signal changes in the caudate and frontopolar cortex were associated with increase in hedonic response during the sequential pleasure experiences. Conclusions. Augmentation of hedonic enjoyment between the predictive and experiential stages of anticipatory pleasure is reduced in schizophrenia because of diminished activity in the reward-related regions during the prediction of pleasure. During cued-emotional experiences of anticipatory pleasure, patients seem to have difficulties in the integration of emotional information. [ABSTRACT FROM AUTHOR]

Aim Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups. Methods Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task ( SART) was used to measure attention capacity. Cerebral blood flow ( CBF) during attention tasks was measured using H215O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups. Results Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group. Conclusion Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia. [ABSTRACT FROM AUTHOR]

Objective: How the brain supports intermediate-term preservation of memory in patients who have undergone unilateral medial temporal lobe resection (MTLR) has not yet been demonstrated. To understand the neural basis of episodic memory in the intermediate term after surgery for temporal lobe epilepsy (TLE), the authors investigated the relationship between the activation of the hippocampus (HIP) during successful memory encoding and individual memory capacity in patients who had undergone MTLR. They also compared hippocampal activation with other parameters, including structural volumes of the HIP, duration of illness, and age at seizure onset., Methods: Thirty-five adult patients who had undergone unilateral MTLR at least 1 year before recruiting and who had a favorable seizure outcome were enrolled (17 left MTLR, 18 right MTLR; mean follow-up 6.31 ± 2.72 years). All patients underwent a standardized neuropsychological examination of memory function and functional MRI scanning with a memory-encoding paradigm of words and figures. Activations of the HIP during successful memory encoding were calculated and compared with standard neuropsychological memory scores, hippocampal volumes, and other clinical variables., Results: Greater activation in the HIP contralateral to the side of the resection was related to higher postoperative memory scores and greater postoperative memory improvement than the preoperative baseline in both patient groups. Specifically, postoperative verbal memory performance was positively correlated with contralateral right hippocampal activation during word encoding in the left-sided surgery group. In contrast, postoperative visual memory performance was positively correlated with contralateral left hippocampal activation during figure encoding in the right-sided surgery group. Activation of the ipsilateral remnant HIP was not correlated with any memory scores or volumes of the HIP; however, it had a negative correlation with the seizure-onset age and positive correlation with the duration of illness in both patient groups., Conclusions: For the first time, a neural basis that supports effective intermediate-term episodic memory after unilateral MTLR has been characterized. The results provide evidence that engagement of the HIP contralateral rather than ipsilateral to the side of resection is responsible for effective memory function in the intermediate term (> 1 year) after surgery in patients who have undergone left MTLR and right MTLR. Engagement of the material-specific contralesional HIP, verbal memory in the left-sided surgery group, and visual memory in the right-sided surgery group were observed.

Aim: Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups., Methods: Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task (SART) was used to measure attention capacity. Cerebral blood flow (CBF) during attention tasks was measured using H(2) (15) O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups., Results: Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group., Conclusion: Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia., (© 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.)