A family study of endophenotypes for psychosis within an early intervention programme in Hong Kong: Rationale and preliminary findings

The study of endophenotypes may be a viable strategy to tackle the genetic complexity and phenotypic heterogeneity of psychosis, but this research direction is relatively under-developed in China as compared to Western countries. We have recently initiated one of the first family studies of endophenotypes for psychosis in China. Patients entering an established early psychosis intervention service are recruited into this research project for phenotyping, endophenotyping and genotyping. At the endophenotypic level, four domains (neurological soft signs, neurocognition of prospective memory, social cognition of facial emotion recognition, and affective cognition of anticipatory and consummatory pleasure) are studied in the sample of patients with psychosis and their unaffected siblings. This article illustrates the benefit of a research-oriented clinical programme and its findings based on the data collected as of early 2011. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.link_to_subscribed_fulltex

Pathway of psychiatric care in Hong Kong

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High frequency diffraction of an electromagnetic plane wave by an imperfectly conducting rectangular cylinder

Copyright @ 2011 IEEEWe shall consider the the problem of determining the scattered far wave field produced when a plane E-polarized wave is incident on an imperfectly conducting rectangular cylinder. By using the the uniform asymptotic solution for the problem of the diffraction of a plane wave by a right-angled impedance wedge, in conjunction with Keller's method, the a high frequency far field solution to the problem is given

Multivariate Neural Representations of Value during Reward Anticipation and Consummation in the Human Orbitofrontal Cortex

The role of the orbitofrontal cortex (OFC) in value processing is a focus of research. Conventional imaging analysis, where smoothing and averaging are employed, may not be sufficiently sensitive in studying the OFC, which has heterogeneous anatomical structures and functions. In this study, we employed representational similarity analysis (RSA) to reveal the multi-voxel fMRI patterns in the OFC associated with value processing during the anticipatory and the consummatory phases. We found that multi-voxel activation patterns in the OFC encoded magnitude and partial valence information (win vs. loss) but not outcome (favourable vs. unfavourable) during reward consummation. Furthermore, the lateral OFC rather than the medial OFC encoded loss information. Also, we found that OFC encoded values in a similar way to the ventral striatum (VS) or the anterior insula (AI) during reward anticipation regardless of motivated response and to the medial prefrontal cortex (MPFC) and the VS in reward consummation. In contrast, univariate analysis did not show changes of activation in the OFC. These findings suggest an important role of the OFC in value processing during reward anticipation and consummation.This study was supported by grants from the National Science Fund China (81088001, 31500894 and 91132701), the Strategic Priority Research Programme (B) of the Chinese Academy of Science (XDB02030002), the Beijing Training Project for the Leading Talents in S & T (Z151100000315020), the Beijing Municipal Science & Technology Commission Grant, and a grant from the initiation fund of the CAS/SAFEA International Partnership Programme for Creative Research Team (Y2CX131003). LS is funded by the NIHR Biomedical Research Centre and Biomedical Research Unit in Dementia based at Cambridge University Hospitals NHS Foundation Trust and the University of Cambridge

Executive dysfunctions in schizophrenia: Relationships to clinical manifestation

Studies suggest that executive functions in patients with schizophrenia are markedly impaired as compared with normal controls. Most previous studies employed tests of executive functions adopted from frontal lobe neuropsychological paradigms based on lesion studies. This study employed several more recently developed theory-driven tests of executive functions addressing the construct of the supervisory attentional system. We explore the pattern of executive function impairment using factor analysis and subsequently investigate the relationships between these executive function factors and the clinical features in a sample of chronic schizophrenic patients. A total of 51 patients with chronic schizophrenia were recruited. The Sustained Attention Response to Task (SART), Six Elements Test (SET) and Hayling Sentence Completion Test (HSC) were used to assess executive functions. Three factors were identified within the executive function tests: 1) The "semantic inhibition factor" comprised items in the HSC, 2) the "action/attention inhibition" factor comprised the SART commission error and the SET rule-breaking score and 3) the"output generation factor" comprised the SET raw score and the correct SART response. Significant relationships were found between these derived factors and clinical features after partialling out the confounding effect of age, education and illness duration. The three theory-based tests of executive function were shown to have good construct validity among the group of chronic schizophrenic patients.link_to_subscribed_fulltex

Problem-solving ability in chronic schizophrenia: A comparison study of patients with traumatic brain injury

We tested the hypothesis that patients with schizophrenia are more prone to impairment in planning and problem-solving as compared with normal controls and patients with traumatic brain injury (TBI) by administering the Tower of Hanoi (TOH) task. A total of one hundred and fifty-three participants (51 in each group) were recruited. The performance of the patient groups was markedly worse than normal controls in terms of profile score, number of rule-breaking behaviour, and mean execution time. Two-way 3 (group) x 6 (complexity) ANOVAs indicated that significant main effects of group and complexity were observed in the number of moves, planning time to initiate the first move and subsequent execution time. The general performance of TOH in the schizophrenia group was very similar to that of the TBI group. Subsequent comparison of sub-groups of frontal and posterior lobe damage indicated the pattern of performance in schizophrenia patients lie between them. Taken together, these findings suggest that neither focal frontal nor temporal lobe damage is a sufficient explanation for the problem-solving deficits in patients with schizophrenia.link_to_subscribed_fulltex

The abandonment of central executive? Fractionation of executive functions in patients with schizophrenia

OBJECTIVE: The purpose of this study was to examine the phenomenon of fractionation of executive attention performance in schizophrenia. METHODS: A group of 90 schizophrenic patients (74 men, 16 women) were recruited. Patients were given a set of frontal executive function sensitive tests to assess initiation, sustained attention, switching and flexibility, impulsivity and disinhbition, strategy allocation and planning. They were also given information subscale and memory subtests of the WAIS-R and WMS-R. We analyzed individual patient’s executive attentional performance with the normative data from our laboratory. Summary scores for all specific executive attention components were computed. For each component, participants were classified as having impairment with their test performance below 1.5 standard deviations of the norms of the corresponding test. RESULTS: The findings showed that there were 27.8% (n = 25) cases demonstrated impaired performance in all executive components and 5.6% (n = 5) exhibited intact performance in all components. About 18.9% (n = 17), 16.7% (n = 15), 21.1% (n = 19), and 10% (n = 9) showed intact performance in 1 component, 2 components, 3 components, and 4 components, respectively. No significant differences were found among the groups in terms of education, gender, and duration of illness. Multiple univariate ANCOVA using age, information and medication as covariates indicated significant differences among the groups in terms of clinical symptoms and non-executive functions. CONCLUSION: These findings suggest there is a fractionation of central executive in this clinical group

The components of executive functioning in a cohort of patients with chronic schizophrenia: A multiple single-case study design

We examined the fractionation of executive functioning performance in ninety patients with schizophrenia, who were tested for initiation, sustained attention, switching/flexibility, attention allocation and impulsivity/ disinhibition. The participants were also given tests of general intelligence and memory. We analysed the executive functioning performance of individual patients against normative data from our laboratory, and summary scores for all of the executive functioning components were computed. For each component, participants were classified as having impairment with a test performance of 1.5 standard deviations or more from the norm of the corresponding test. Of all of the participants, 27.8% (n = 25) demonstrated poor performance in all of the components, and 5.6 % (n = 5) exhibited intact or fair performance in all of the components. Furthermore, 18.9% (n = 17) showed intact or fair performance in one component, 16.7% (n = 15) in two components, 21.1% (n = 19) in three components and 10% (n = 9) in four components. The groups did not differ in education, gender or duration of illness, but the group that showed impaired performance in all of the components demonstrated the most severe psychotic symptoms after controlling for background intelligence, age and medication. The differential breakdown for the executive functioning performance across the participants suggests that the fractionation of central executive functioning occurs in schizophrenia. © 2005 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex