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  • Paracingulate sulcus asymmetry; sex difference, correlation with semantic fluency and change over time in adolescent onset psychosis.

    24 October 2018

    The left paracingulate sulcus (PCS) is longer than the right and the adjacent cortex is activated by the generation of words. In adult patients with chronic schizophrenia the anatomical asymmetry is reduced. In 35 controls and 38 adolescents with schizophrenia or schizoaffective disorder (mean age = 16 years) we found that semantic verbal fluency correlated with leftward PCS asymmetry in controls but not in patients. At intake, PCS length did not differ between patients and controls, but at follow-up (13 controls, 10 patients, mean age = 18 years) PCS asymmetry (comprising both increasing left and decreasing right length) increased significantly, the increase was greater in males than in females, and there was a trend for a diagnosis * sex * side * time interaction such that in controls leftward PCS asymmetry increased, while in patients of both sexes there was convergence toward symmetry. Thus sulcal anatomy develops differentially in the two sexes during adolescence, and the pattern of asymmetric sex-dependent change over time may distinguish patients with psychosis from controls. Greater change in asymmetry during adolescence may explain earlier age of onset in males and greater deficits in verbal fluency.

  • Application of a new image analysis technique to study brain asymmetry in schizophrenia.

    24 October 2018

    The hypothesis that normal brain torque (i.e. rightward frontal and leftward occipital asymmetry) is anomalous in schizophrenia (Crow, 1997. Trends in Neuroscience, 20, 339-343) was tested by application of a novel image analysis technique on three-dimensional magnetic resonance images obtained in 26 adult patients with chronic schizophrenia (18 males, 8 females) and 24 controls (14 males, 10 females). Right and left cerebral hemisphere tissue was extracted via non-linear co-registration with a mask image, and maps were computed of inter-hemispheric differences in tissue volume in an array of columns of voxels orthogonal to the mid-plane (2D), and profiles of coronal slice volumes (1D). Furthermore, integration of two-dimensional column maps gave approximate lobar asymmetries, and occipital and frontal asymmetries were combined to give a volumetric measure of brain torque. Significant brain torque was revealed in male and female control and patient groups, and did not correlate with brain size. Frontal and occipital asymmetries were significantly correlated in all groups. Both frontal and occipital components of torque were significantly increased in males than females. Patients tended to have reduced torque, particularly the leftward occipital component. Furthermore, 3/26 patients (but no controls) had reversed torque (leftward frontal and rightward occipital asymmetry). Contrary to Crow's hypothesis, brain torque was not significantly reduced in patients with schizophrenia relative to controls, although reversal of torque was found in three cases. Future studies with larger sample sizes should consider sexual dimorphism and specific symptoms in relation to asymmetry.

  • The challenges of developing a collaborative data and compute grid for neurosciences

    24 October 2018

    The three-year UK NeuroGrid project aims to develop a Grid-based collaborative research environment to support the data and compute needs for a UK Neurosciences community. This paper describes the challenges in developing this architecture and details initial results from the development of its first prototype to support psychosis, dementia and stroke research and the social challenges of such a collaborative research project. The paper discusses approaches being taken to explore the collaborative science process to inform the requirements for follow on prototypes and methods utilized to develop an effective project team. © 2006 IEEE.