The importance of autonomy support and the mediating role of work motivation for well-being: testing self-determination theory in a Chinese work organisation.

We examine relations between perceived organisational autonomy support and different types of work motivation and well-being outcomes in 266 teachers from two government schools in China. We hypothesised that greater autonomy support would be associated with more autonomous forms of employee motivation, and that teacher motivation would in turn mediate the effects of autonomy support on indicators of work well-being (i.e., job satisfaction, work stress and physical ill symptoms). Results generally supported the hypothesised relations between perceived autonomy support and SDT's five types of motivations. Findings also showed that perceived autonomy support predicted job satisfaction directly and indirectly through the mediating roles of intrinsic motivation, identified regulation, introjected regulation and external regulation. Perceived autonomy support predicted work stress directly and indirectly through the mediating roles of external regulation and amotivation. Autonomy support also predicted illness symptoms via the mediating roles of intrinsic motivation, introjected regulation and amotivation. The current findings highlight how perceived organisational support for autonomy relates to motivational differences in a Chinese work context, and the potential relevance of autonomy support for employee well-being.

ARVCF genetic influences on neurocognitive and neuroanatomical intermediate phenotypes in Chinese patients with schizophrenia.

OBJECTIVE: There are notable similarities between velocardiofacial syndrome and schizophrenia in terms of neurocognitive deficits and brain structural abnormalities. These similarities have supported the role of the armadillo repeat gene deleted in velocardiofacial syndrome (ARVCF) as a susceptibility gene in schizophrenia. This study investigated the relationships between haplotypes of the ARVCF gene and specific intermediate phenotypes in schizophrenia. We hypothesized that ARVCF gene haplotypes influence caudate nucleus volume, fractional anisotropy, and neurocognitive functioning in schizophrenia. METHOD: Between May 2006 and November 2009, 200 Chinese participants (125 patients with DSM-IV diagnosis of schizophrenia and 75 controls) were genotyped using blood samples, and a subset of 166 participants (99 patients with DSM-IV diagnosis of schizophrenia and 67 controls) underwent structural magnetic resonance imaging, diffusion tensor imaging, and completed neuropsychological testing. RESULTS: The haplotype T-G-A-T-T-G-G-C-T-G-T (ARVCF-Hap1) was significantly associated with fractional anisotropy of the caudate nucleus and executive functioning in patients. Specifically, patients with more copies of ARVCF-Hap1 have lower white matter integrity in caudate nucleus (P = .0008) and greater perseverative errors (P = .00003) on the Wisconsin Card Sorting Test. A trend of lower caudate volume (P = .015) in patients with more copies of ARVCF-Hap1 was also observed. CONCLUSIONS: These findings are consistent with known ARVCF gene effects on neurodevelopment in terms of cellular arrangement, migration, and intracellular signaling involving the striatum and may involve interactions with other brain networks such as prefrontal cortex, and they underscore the importance of imaging-genetic studies to elucidate the genetic influences underlying intermediate phenotypes in complex neurobehavioral disorders.

Use of normative distribution of gray to white matter ratio in orthogonal planes in human brain studies and computer-assisted neuroradiology.

PURPOSE: Although the brain has been extensively studied, relationships of gray (GM) to white (WM) matters in individual sections as typically acquired and read radiologically have not yet been examined. A novel GM/WM-based approach with a compact whole brain representation is introduced and applied to study the brain and perform neuroimage processing. METHODS: The gray to white matter ratio GWR defined as GM/(GM+WM) was calculated for 3T T1-weighted axial, coronal, and sagittal sections of 75 normal subjects. The mean (normative) GWR curves were employed to describe the normal brain and quantify aging and to illustrate pathology detection and characterization. RESULTS: The mean GWR curves characterize the normal brain by only six, neuroanatomy-related numbers. The regions with a significant GWR decline with age surround the ventricular system. The GWR decline rate in males is higher (-0.17%/year) than females (-0.14%/year); moreover, males show a significantly higher decline in middle to elder group. The GWR decline from young (≤25 years) to middle (26-40 years) age group (males/females -0.31%/-0.34%/year) is significantly higher than that from middle to elder (>40 years) group (males/females -0.13/-0.07%/year). CONCLUSION: The GWR-based analysis is useful to characterize normal brain, determine significant regions of interest, and quantify healthy aging. It has potential applications in brain compression, comparison, morphometry, normalization, and detecting and quantifying pathologies, which open new avenues in computer-assisted neuroradiology from screening to large brain databases searching.

Cortical and subcortical white matter abnormalities in adults with remitted first-episode mania revealed by Tract-Based Spatial Statistics.

OBJECTIVES: Abnormalities of brain white matter have been noted in structural magnetic resonance imaging and diffusion tensor imaging (DTI) studies of bipolar disorder, but there are fewer investigations specifically examining white matter integrity early in the course of illness. In this study, we employed DTI to elucidate white matter changes in adult patients with remitted first-episode mania and hypothesized that first-episode mania was associated with decreased fractional anisotropy in cortical (frontal) and subcortical (thalamus, striatum) white matter as well as white matter tracts (cingulum, corpus callosum). METHODS: Diffusion tensor images were acquired from 16 patients with remitted first-episode mania and 16 healthy controls matched for age, gender, handedness, and years of education. Fractional anisotropy and radial and axial diffusivities were analyzed using Tract-Based Spatial Statistics. RESULTS: Patients had lower fractional anisotropy and higher radial diffusivity in the left anterior frontal white matter, right posterior thalamic radiation, left cingulum, and bilateral sagittal striatum. In addition, increased radial diffusivity was found in the left corpus callosum. CONCLUSION: Our findings highlighted that white matter abnormalities were present by the time of remission of first-episode mania. The widespread occurrence of these white matter abnormalities both in first-episode mania and chronic bipolar disorder suggested that disruption of white matter cortical-subcortical networks as well as projection, associative, and commissural tracts is a hallmark of the illness.

The Schizophrenia Cognition Rating Scale: validation of an interview-based assessment of cognitive functioning in Asian patients with schizophrenia.

Growing interest in cognitive deficits associated with schizophrenia has led to the need for a clinician-friendly cognitive instrument. The Schizophrenia Cognition Rating Scale (SCoRS), recognized for its brevity and ease of administration, has proven to be a valid and reliable measure of overall cognition in schizophrenia patients. However, there has been no such validation in an Asian context. This SCoRS validation study involved 103 patient and 48 control subjects within an Asian population. Test-retest reliability, sensitivity of the instrument to cognitive differences between patients with schizophrenia and healthy controls as well as validity by comparing with a standardised performance-based cognitive battery, the Brief Assessment of Cognition in Schizophrenia (BACS) were assessed. Our findings indicated that SCoRS is highly reliable (ICC=0.984) and sensitive to cognitive dysfunction. SCoRS is significantly correlated with BACS composite scores and predicted functional outcomes as measured by Global Assessment of Functioning (GAF) and World Health Organisation-Quality of Life (WHO QOL) within an Asian population. SCoRS represents a clinician-friendly cognitive assessment tool that incorporates third-party feedback and might be employed in clinical practice to better evaluate and manage schizophrenia.

Neurocognitive, clinical and functional correlates of subjective quality of life in Asian outpatients with schizophrenia.

Quality of life (QOL) impairment is evident in patients with schizophrenia and is increasingly recognised as an important evaluation criterion of treatment outcome. Hence, this study aimed to identify the neurocognitive, clinical and functional parameters associated with subjective QOL in patients with schizophrenia within an Asian context, and specifically in an outpatient setting. This study was conducted on 83 outpatients with DSM-IV diagnosis of schizophrenia, and 47 age- and gender-matched healthy controls. All participants were administered with the World Health Organisation Quality of Life Assessment-Brief Form (WHOQOL-BREF) and Brief Assessment of Cognition in Schizophrenia (BACS), to measure quality of life and cognitive function respectively. Patients were also assessed for severity of psychopathology, as well as level of psychosocial functioning, using the Positive and Negative Syndrome Scale (PANSS) and Global Assessment of Functioning (GAF) rating scales respectively. Specific psychopathology (greater severity of PANSS negative symptoms, general psychopathology subscale scores), cognitive deficits (working and verbal memories), and lower GAF scores were correlated with poorer QOL in patients. Multivariate analyses revealed that younger age, being single and lower level of psychosocial functioning were associated with poorer QOL but level of psychosocial functioning did not appear to mediate the effects of symptoms and neurocognitive deficits on QOL. Overall, this study highlighted the need for clinicians to pay more attention to these clinical, neurocognitive and functional parameters and their integrative relationships with QOL in order to optimise the treatment outcomes of patients with schizophrenia.

White matter abnormalities in first-episode schizophrenia: a combined structural MRI and DTI study.

This study examined white matter volume change and integrity jointly in patients with first-episode schizophrenia using an empirically derived region of interest approach and novel Diffusion Tensor Imaging (DTI) geometric indices. Structural images from 103 individuals comprising of 39 patients with first-episode schizophrenia and 64 healthy controls were examined for regions of white matter volume change using voxel-based morphometry (VBM). These regions were then further interrogated for group differences employing geometric indices in addition to fractional anisotropy (FA).VBM analyses revealed that patients with first-episode schizophrenia had lower white matter volume in the right temporal-occipital region (p<0.005) corresponding to the inferior longitudinal fasciculus. Further analyses of diffusion anisotropy in the right temporal-occipital region revealed lower planar anisotropy, and higher linear anisotropy (p=0.012) in patients. FA in the implicated region was also found to be correlated with severity of delusions (r=0.47, p=0.004).We confirmed previous findings of lower white matter volume in the region of inferior longitudinal fasciculus. The presence of changes in geometric diffusion indices in the implicated white matter region suggested that pathophysiological processes which underlie cerebral white matter volume reduction may not be reflected by changes in FA. Further research is needed to better understand the nature of these white matter changes and its progression in schizophrenia over time.

Duration of illness, regional brain morphology and neurocognitive correlates in schizophrenia.

INTRODUCTION: Previous studies examining brain effects of duration of illness in schizophrenia have focused on either cortical or subcortical structures. Hence this study sought to elucidate the regional grey matter changes (both cortical and subcortical) and neurocognitive correlates with increased duration of illness in a large sample of patients with schizophrenia using voxel-based morphometry. MATERIALS AND METHODS: Ninety patients (72 males and 18 females) with DSM-IV diagnosis of schizophrenia were recruited and assessed using magnetic resonance imaging and a battery of neuropsychological tests. RESULTS: A longer duration of illness was associated with smaller grey matter volumes in the left superior frontal gyrus, bilateral putamen, right superior temporal gyrus, right superior occipital gyrus as well as the right thalamus. No region showed increased grey matter volume above threshold with longer duration of illness. Longer duration of illness was correlated with poorer attention. CONCLUSIONS: The grey matter reductions in different brain regions highlighted that a distributed network of cortical and subcortical regions was associated with duration of illness. This is consistent with neural models that implicate involvement of thalamo-cortical circuitry as the disruption in these neural pathways can result in specific deficits such as poorer attention. The results have implications for the understanding of brain changes in schizophrenia, and with further studies, may guide better tailored and targeted clinical management in terms of reducing the impact of duration of illness on neural substrates in schizophrenia in the future.

Functional imaging of working memory following normal sleep and after 24 and 35 h of sleep deprivation: Correlations of fronto-parietal activation with performance.

Working memory was evaluated after normal sleep, and at 24 and 35 h of sleep deprivation (SD) in 26 healthy young adults to examine the neural correlates of inter-individual differences in performance. The extent of performance decline was not significantly different between the two SD test periods although there was greater variability in performance at SD35. In both SD sessions, there was reduced task-related activation (relative to normal sleep) in both superior parietal regions and the left thalamus. Activation of the left parietal and left frontal regions after normal sleep was negatively correlated with performance accuracy decline from normal sleep to SD24 thus differentiating persons who maintained working memory performance following SD from those who were vulnerable to its effects.

Grouping with and without attention.

The effects of perceptual grouping on a line discrimination task were investigated using Moore and Egeth's (1997) paradigm. Observers judged which of two lines, presented one above the other over a matrix of spots, was longer. On some trials, larger spots at both ends of the lines formed arrowheads, thereby making possible the Müller-Lyer illusion. When observers attended only to the lines, they were not aware of the arrowheads. Yet their line judgment performance showed that they had succumbed to the illusion. When the observers' attention was directed to the arrowheads but they nevertheless failed to discern the arrowheads' orientation, their line judgments were still influenced by the illusion.