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Previous research has shown mild forms of the neurocognitive impairments seen in schizophrenia among healthy individuals exhibiting high schizotypal traits. This study aimed to explore associations between schizotypy and cognitive performance in an adult community sample. Ninety-five females and 79 males completed the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), which measures four separable aspects of schizotypy: cognitive disorganization, unusual experiences, introvertive anhedonia, and impulsive non-conformity. Subsequently, participants were administered a neurocognitive battery incorporating measures of executive skills including inhibition, cognitive flexibility, reasoning, and problem solving along with measures of attention and processing speed and both verbal and spatial working memory. In line with predictions, the current study found that higher scores on the subscales of unusual experiences, cognitive disorganization, and impulsive non-conformity related to worse performance on a measure of inhibition. Additionally, as introvertive anhedonia increased, both attention and processing speed and reasoning and problem-solving performance became more impaired. In conclusion, this study extends schizotypy literature by examining the subscales of the O-LIFE, and enables inferences to be drawn in relation to cognitive impairment in schizophrenia.

Introduction: Executive dysfunction is well established in patients with traumatic brain injury and in schizophrenia (SCZ). However, assessments of executive function in psychosis following traumatic brain injury (PFTBI) are limited and inconsistent, and often do not reflect the deficits demonstrated in patients with traumatic brain injury (TBI) or SCZ. We sought to determine the extent of executive dysfunction in PFTBI relative to three comparison cohorts., Method: Measures of executive function were administered to dually diagnosed patients with PFTBI (n = 10) including tests of mental inhibition and switching, processing speed, and attention: the Stroop Task, Trail Making Test (TMT), and the Attention subtest of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Demographically comparable patients with TBI (n = 10), SCZ (n = 23), and healthy controls (n = 23) underwent an identical battery., Results: Significant executive dysfunction was evident in patients with PFTBI on all measures. Relative to all three comparison cohorts patients with PFTBI performed most poorly., Conclusions: These data present novel evidence of substantially impaired executive function across four task types in PFTBI and suggest that TBI and psychosis have an additive influence on executive function deficits. Treatment programs requiring substantial executive engagement are not suitable for patients dually diagnosed with PFTBI.

Objectives: Body dysmorphic disorder (BDD) is characterized by a preoccupation with a misperceived flaw in appearance, causing significant distress and disability. Neuropsychological research has revealed deficits in executive function and inhibitory control of emotional responses. The few previous structural neuroimaging studies have had inconclusive findings and we aimed to take this field of research forward by contributing high quality structural data., Methods: To investigate regional brain volumes we compared 20 BDD participants and 20 matched controls using high-resolution structural T1-weighted magnetic resonance imaging (MRI). The MRI data was subjected to cortical reconstruction and volumetric segmentation using Freesurfer software., Results: Results showed the right orbitofrontal cortex, bilateral thalamus, left anterior cingulate cortex, hippocampus and amygdala were significantly smaller in the BDD sample compared to controls. The most pronounced differences were in the right orbitofrontal cortex and left anterior cingulate cortex, as these areas were smaller in BDD participants independent of reduced global brain volumes. Duration of illness significantly negatively correlated with right orbitofrontal cortex volumes., Conclusions: This is the largest volumetric neuroimaging study in BDD to date and provides important data on volumetric differences that implicate fronto-limbic circuits., (© The Royal Australian and New Zealand College of Psychiatrists 2014.)

Salmonella enterica sv. Typhimurium is an established model organism for Gram-negative, intracellular pathogens. Owing to the rapid spread of resistance to antibiotics among this group of pathogens, new approaches to identify suitable target proteins are required. Based on the genome sequence of S. Typhimurium and associated databases, a genome-scale metabolic model was constructed. Output was based on an experimental determination of the biomass of Salmonella when growing in glucose minimal medium. Linear programming was used to simulate variations in the energy demand while growing in glucose minimal medium. By grouping reactions with similar flux responses, a subnetwork of 34 reactions responding to this variation was identified (the catabolic core). This network was used to identify sets of one and two reactions that when removed from the genome-scale model interfered with energy and biomass generation. Eleven such sets were found to be essential for the production of biomass precursors. Experimental investigation of seven of these showed that knockouts of the associated genes resulted in attenuated growth for four pairs of reactions, whilst three single reactions were shown to be essential for growth., (© 2014 The Authors.)

A core symptom of schizophrenia is thought disorder (TD). The cognitive abilities of semantic processing and executive function are argued to be etiologically linked to TD. However, there has been no comprehensive investigation of neurocognition in TD to date. The neurocognitive profile of 58 schizophrenia patients and 48 healthy controls was examined using the MATRICS Consensus Cognitive Battery and the D-KEFS Color-Word Interference Test. TD patients performed more poorly than non-TD patients on the cognitive domains of Verbal Learning and Inhibition, reflective of semantic and executive function respectively, confirming their critical roles over and above other cognitive deficits in schizophrenia., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of low-grade fibrosarcoma, with specific histological and immunohistochemical features and a poor prognosis. We report a case of SEF of the paravertebral column in a 49-year old male who presented a paraspinal mass with extension into the L4-L5 neural foramen and invasion of the L5 nerve root. Histology of the tumourectomy specimen and its immunohistochemical study led to the diagnosis of SEF. This case was particularly unusual due to its paravertebral column location and, despite its low grade, illustrates the malignant potential of SEF., (Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.)

The large size of metabolic networks entails an overwhelming multiplicity in the possible steady-state flux distributions that are compatible with stoichiometric constraints. This space of possibilities is largest in the frequent situation where the nutrients available to the cells are unknown. These two factors: network size and lack of knowledge of nutrient availability, challenge the identification of the actual metabolic state of living cells among the myriad possibilities. Here we address this challenge by developing a method that integrates gene-expression measurements with genome-scale models of metabolism as a means of inferring metabolic states. Our method explores the space of alternative flux distributions that maximize the agreement between gene expression and metabolic fluxes, and thereby identifies reactions that are likely to be active in the culture from which the gene-expression measurements were taken. These active reactions are used to build environment-specific metabolic models and to predict actual metabolic states. We applied our method to model the metabolic states of Saccharomyces cerevisiae growing in rich media supplemented with either glucose or ethanol as the main energy source. The resulting models comprise about 50% of the reactions in the original model, and predict environment-specific essential genes with high sensitivity. By minimizing the sum of fluxes while forcing our predicted active reactions to carry flux, we predicted the metabolic states of these yeast cultures that are in large agreement with what is known about yeast physiology. Most notably, our method predicts the Crabtree effect in yeast cells growing in excess glucose, a long-known phenomenon that could not have been predicted by traditional constraint-based modeling approaches. Our method is of immediate practical relevance for medical and industrial applications, such as the identification of novel drug targets, and the development of biotechnological processes that use complex, largely uncharacterized media, such as biofuel production.

The promise of proteomics and fluxomics is limited by our current inability to integrate these two levels of cellular organization. Here we present the derivation, experimental parameterization, and appraisal of flux functions that enable the quantitative prediction of changes in metabolic fluxes from changes in enzyme levels. We based our derivation on the hypothesis that, in the determination of steady-state flux changes, the direct proportionality between enzyme concentrations and reaction rates is principal, whereas the complexity of enzyme-metabolite interactions is secondary and can be described using an approximate kinetic format. The quality of the agreement between predicted and experimental fluxes in Lactococcus lactis, supports our hypothesis and demonstrates the need and usefulness of approximative descriptions in the study of complex biological systems. Importantly, these flux functions are scalable to genome-wide networks, and thus drastically expand the capabilities of flux prediction for metabolic engineering efforts beyond those conferred by the currently used constraints-based models., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Cognitive behavioural therapy has been established as an effective treatment for residual psychotic symptoms but a substantial proportion of people do not benefit from this treatment. There has been little direct study of predictors of outcome, particularly in treatment targeting auditory hallucinations., Method: The Psychotic Symptom Rating Scales (PSYRATS) and Positive and Negative Syndrome Scale (PANSS) were administered pre- and post-therapy to 33 people with schizophrenia-related disorders receiving CBT for auditory hallucinations in a specialist clinic. Outcome was compared with pre-therapy measures of insight, beliefs about the origin of hallucinations, negative symptoms and cognitive disorganization., Results: There were significant improvements post-treatment on the PSYRATS and PANSS Positive and General Scales. Improvement on the PSYRATS was associated with lower levels of negative symptoms, but was unrelated to overall insight, delusional conviction regarding the origins of hallucinations, or levels of cognitive disorganization., Conclusions: Lack of insight and presence of formal thought disorder do not preclude effective cognitive-behavioural treatment of auditory hallucinations. There is a need to further understand why negative symptoms may present a barrier to therapy.

Regulation analysis is a methodology that quantifies to what extent a change in the flux through a metabolic pathway is regulated by either gene expression or metabolism. Two extensions to regulation analysis were developed over the past years: (i) the regulation of V(max) can be dissected into the various levels of the gene-expression cascade, such as transcription, translation, protein degradation, etc. and (ii) a time-dependent version allows following flux regulation when cells adapt to changes in their environment. The methodology of the original form of regulation analysis as well as of the two extensions will be described in detail. In addition, we will show what is needed to apply regulation analysis in practice. Studies in which the different versions of regulation analysis were applied revealed that flux regulation was distributed over various processes and depended on time, enzyme, and condition of interest. In the case of the regulation of glycolysis in baker's yeast, it appeared, however, that cells that remain under respirofermentative conditions during a physiological challenge tend to invoke more gene-expression regulation, while a shift between respirofermentative and respiratory conditions invokes an important contribution of metabolic regulation. The complexity of the regulation observed in these studies raises the question what is the advantage of this highly distributed and condition-dependent flux regulation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: The current study examined executive functioning in schizophrenia by assessing response initiation and suppression in a group of schizophrenia patients, and drawing comparisons with psychiatric and non-psychiatric control groups., Method: The Hayling Sentence Completion Test was used as a measure of executive functioning and was completed by 39 schizophrenia patients, 40 bipolar disorder patients and 44 healthy control participants. Outcome measures included response initiation and response suppression latency and error rate., Results: The schizophrenia group was significantly impaired on all measures of the Hayling Sentence Completion Test when compared to healthy control participants, and only on some of the measures when compared to the bipolar disorder group. The bipolar disorder group did not differ in performance compared to the healthy control group. Overall schizophrenia patients showed longer response initiation and response suppression latencies, and an increased error rate. Performance of the schizophrenia patients was associated with higher ratings of cognitive disorganisation. Performance was not related to age, gender, predicted IQ or any other clinical characteristics., Conclusions: Schizophrenia patients show a slowing in baseline response initiation and slowed suppression of an inappropriate response. Considering the bipolar disorder patients demonstrated intact performance, altered executive functioning in schizophrenia appears relatively specific to the disorder rather than reflecting other characteristics common to mental illness. Investigations examining which neurocognitive domains are impaired in schizophrenia provide direct implications for treatment options tailored to an individual's cognitive strengths and weaknesses.

Prepulse inhibition (PPI) is a measure of sensorimotor gating or information processing. Few studies have examined PPI in bipolar disorder (BD); two studies reported a PPI disruption and two reported no change. There are gender differences in PPI and within the clinical profile of BD, which may explain some of these discrepancies. Thus, the effect of gender on PPI in BD was the focus of the current study. Euthymic BD patients (14 male/15 female) were compared to age- and IQ-matched healthy control participants (16 male/16 female). Assessment of PPI included 21 pulse-alone trials (115 dB) and a total of 42 prepulse-pulse trials (seven of each prepulse: 74, 78, 86 dB) at two stimulus onset asynchrony levels (SOA: 60, 120 ms). There was a group x SOA and a group x gender interaction, reflecting that men with BD showed reduced PPI compared to control males at the 60-ms SOA (3% in BD vs. 26% in controls), but not the 120-ms SOA. In contrast, women with BD had significantly increased PPI compared to female controls at the 120-ms SOA (49% in BD vs. 29% in controls), but not the 60-ms SOA. Compared to control participants BD patients showed changes in PPI, which are gender-dependent; male BD participants had reduced PPI, whereas female BD participants had increased PPI. This gender difference highlights the need to consider men and women with BD as two distinct groups, at least in PPI studies.

Evidence suggests schizophrenia patients may have problems integrating visual features into perceptual wholes using configural information. This deficit may impact on higher order socio-cognitive abilities such as facial emotion perception. Twenty-six schizophrenia patients and 26 age and gender matched healthy control participants completed a Fractured Faces Task which disrupted configural face information yet maintained featural information. While participants were matched for performance when viewing whole, unaltered faces; schizophrenia patients were significantly less affected than control participants when the configural information was disrupted. The results indicate altered configural processing and potential over-reliance on featural processing in schizophrenia. The implications of such impaired processing strategies are discussed.

A number of techniques have been used to provide functional connectivity estimates for a given fMRI data set. In this study we compared two methods: a 'rest-like' method where the functional connectivity was estimated for the whitened residuals after regressing out the task-induced effects, and a within-condition method where the functional connectivity was estimated separately for each experimental condition. In both cases four pre-processing strategies were used: 1) time courses extracted from standard pre-processed data (standard); 2) adjusted time courses extracted using the volume of interest routines in SPM2 from standard pre-processed data (spm); 3) time courses extracted from ICA denoised data (standard denoised); and 4) adjusted time courses extracted from ICA denoised data (spm denoised). The temporal correlation between time series extracted from two cortical regions were statistically compared with the temporal correlation between a time series extracted from a cortical region and a time series extracted form a region placed in CSF. Since the later correlation is due to physiological noise and other artifacts, we used this comparison to investigate whether rest-like and task modulated connectivity could be estimated from the same data set. The pre-processing strategy had a significant effect on the connectivity estimates with the standard time courses providing larger connectivity values than the spm time courses for both estimation methods. The CSF comparison indicated that for our data set only rest-like connectivity could be estimated. The rest-like connectivity values were similar with connectivity estimated from resting state data., ((c) 2007 Wiley-Liss, Inc.)

Background: Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis., Aims: To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis., Method: We obtained dual-echo (proton density/T2-weighted) magnetic resonance images and carried out voxel-based analysis on the images of 73 patients with first-episode psychosis (schizophrenia n=44, affective psychosis n=29) and 58 healthy controls., Results: Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold., Conclusions: Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas.

Metabolic fluxes may be regulated "hierarchically," e.g., by changes of gene expression that adjust enzyme capacities (V(max)) and/or "metabolically" by interactions of enzymes with substrates, products, or allosteric effectors. In the present study, a method is developed to dissect the hierarchical regulation into contributions by transcription, translation, protein degradation, and posttranslational modification. The method was applied to the regulation of fluxes through individual glycolytic enzymes when the yeast Saccharomyces cerevisiae was confronted with the absence of oxygen and the presence of benzoic acid depleting its ATP. Metabolic regulation largely contributed to the approximately 10-fold change in flux through the glycolytic enzymes. This contribution varied from 50 to 80%, depending on the glycolytic step and the cultivation condition tested. Within the 50-20% hierarchical regulation of fluxes, transcription played a minor role, whereas regulation of protein synthesis or degradation was the most important. These also contributed to 75-100% of the regulation of protein levels.

BDD remains an understudied psychiatric disorder. Further research is required to establish its etiopathology and neurocognitive underpinnings. Its relationship to other psychiatric disorders requires clarification. Also needed is a much better understanding of the best treatments to adopt should conventional approaches (eg, SRIs, CBT) fail.

Semantic processing deficits are present in schizophrenia and are particularly evident on semantic priming tasks. Using high schizotypes (psychosis-prone individuals) can overcome some confounds involved in studying actively symptomatic schizophrenics. In the current study, 26 high and 32 low scorers on the O-LIFE schizotypy scale (from a sample of 251 students) were selected for testing. All subjects were administered a lexical-decision semantic priming task where half the stimuli had a short 200 ms stimulus onset asynchrony (SOA, length of time from onset of prime to onset of target) and half the stimuli had a long 750 ms SOA. In addition, half the words were of high frequency and half of a low frequency. There were no group differences in priming for words of different frequencies. Low schizotypes showed greater priming at the 200 ms SOA than at the 750 ms SOA, whilst individuals with high schizotypy showed the opposite pattern. The pattern shown by the low schizotypes replicates earlier work by the authors using other normal control samples; establishing that there is greater priming under conditions of automatic spreading of activation. Furthermore, the data shows there is not an increase in automatic spreading of activation in individuals with high schizotypy. There has been controversy in the schizophrenia literature over whether there is increased priming under automatic conditions. The current study suggests that, when confounds are controlled for, schizophrenia-like symptoms are not related to an increase in automatic spreading of activation.

An important question is to what extent metabolic fluxes are regulated by gene expression or by metabolic regulation. There are two distinct aspects to this question: (i) the local regulation of the fluxes through the individual steps in the pathway and (ii) the influence of such local regulation on the pathway's flux. We developed regulation analysis so as to address the former aspect for all steps in a pathway. We demonstrate the method for the issue of how Saccharomyces cerevisiae regulates the fluxes through its individual glycolytic and fermentative enzymes when confronted with nutrient starvation. Regulation was dissected quantitatively into (i) changes in maximum enzyme activity (Vmax, called hierarchical regulation) and (ii) changes in the interaction of the enzyme with the rest of metabolism (called metabolic regulation). Within a single pathway, the regulation of the fluxes through individual steps varied from fully hierarchical to exclusively metabolic. Existing paradigms of flux regulation (such as single- and multisite modulation and exclusively metabolic regulation) were tested for a complete pathway and falsified for a major pathway in an important model organism. We propose a subtler mechanism of flux regulation, with different roles for different enzymes, i.e., "leader," "follower," or "conservative," the latter attempting to hold back the change in flux. This study makes this subtlety, so typical for biological systems, tractable experimentally and invites reformulation of the questions concerning the drives and constraints governing metabolic flux regulation.

Capillary zone electrophoresis is capable of analyzing nanoliter volumes, reducing the challenge posed by brain microdialysis time resolution improvement to the management of nanoliter dialysate volumes. This fact has not been overlooked and 12- and 6-s time resolution microdialysis have been reported in anesthetized rats. However, behavioral experiments require fully awake and freely moving animals. To achieve high temporal resolution brain microdialysis in awake unrestrained rats, we have developed an online device that mixes the outflowing dialysate with fluorescein isothiocyanate and buffer within a 26-nl reactor. The mixture was continuously accumulated in a 99-micrometer-bore capillary tube. After the experiment the tube was cut into 4-mm pieces and the content of each piece (30 nl, equivalent to 1 s dialysate) was transferred to a test tube. After allowing 18 h for derivatization, the samples were diluted with water and injected into a capillary electrophoresis laser-induced fluorescence detection instrument. This protocol was tested first in an in vitro assay and proved to be capable of detecting glutamate concentration changes in only 1 s. For the in vivo assays, a probe was inserted into the primary somatosensory cortex of eight rats divided in two groups. One group was stimulated by gently moving its whiskers for 10 s. The other group had no whisker manipulation. Moving the whiskers released glutamate in the experimental group. The first and only change was observed at the 12th s. This method allows 1-s time resolution brain microdialysis in freely moving rats and multiple amino acid analysis every second during sensory perception or motor actions in behavioral experiments.

Work on implicit memory in normal subjects has demonstrated the influence of stimulus modality on the retrieval of semantic information. The present study examined the effects of auditory and visual semantic priming on the recognition of visual words using a lexical decision task. Performance was studied in a group of 20 patients with DSM-IV schizophrenia and 26 normal volunteers of similar age and sex. There were two versions of the task: ipsimodal, in which the word or nonword visual target followed 400 ms after the onset of a visual word prime which may or may not be semantically related to the target; and cross-modal, in which the visual target followed 400 ms after the onset of an auditory word prime. Both groups showed significant priming in both modality conditions, although the schizophrenia patients exhibited significantly greater priming in the cross-modal condition. Priming effects in the ipsimodal condition did not differ substantially between patients and controls. The priming effects in the two conditions correlated with each other in the schizophrenia patients only. The results suggest that priming may occur through amodal semantic representations. In schizophrenia, there appears to be increased cross-modal connectivity (reduced modality modularity and informational encapsulation) between lexical representations that could result in impaired language, particularly speech, processing.

There is evidence that systemic administration of haloperidol, a dopamine receptor blocker, attenuates visual cortex evoked potentials. However, there is scarce information on cortical neurochemical changes associated with haloperidol effects on visual function. The present experiment was designed to investigate: (1) the effect of photic stimulation on glutamate release in the visual cortex; and (2) whether systemic administration of haloperidol would affect those neurochemical changes. Microdialysis probes were implanted in the occipital cortex. Glutamate levels were measured every 30 s using capillary zone electrophoresis. Extracellular glutamate levels increased to about 282% 30 s after photic stimulation started and remain elevated for the 3 min that the photic stimulation lasted. Haloperidol (1.5 and 5 mg/kg, i.p.) completely suppressed the increased of glutamate efflux during photic stimulation. Finally, it was also found that the highest dose of haloperidol (5 mg/kg) did not change glutamate basal levels. The results are discussed with reference to possible dopaminergic actions on the visual system function.

Initial attempts to increase fermentative capacity of baker's yeast focussed on the overproduction of single enzymes, which proved to be insufficient. Nowadays many components of the system are monitored simultaneously in a search for a correlation with fermentative capacity. However, this strategy has not yet proven fruitful either. Here we investigate an element previously neglected, the glucose transporter, and find that a loss of glucose transport capacity correlates with a decrease of fermentative capacity during nutrient starvation. However the correlation is not unique, suggesting that the loss of fermentative capacity cannot be attributed to an inactivation of glucose transport alone. Our results suggest the necessity to use a detailed kinetic model as an underlying working hypothesis and to use Metabolic Control Analysis to examine the pathway's control properties.

The study of cognitive deficits in schizophrenia has recently focused upon semantics: the study of meaning. Delusions are a plausible manifestation of abnormal semantics because by definition they involve changes in personal meaning and belief. A symptom-based approach was used to investigate semantic and phonological fluency in a group of schizophrenic patients subdivided into those with delusions and those with no current delusions. The results demonstrated that deluded patients only were differentially impaired on a test of semantic fluency in comparison to phonological fluency. All subjects showed the same decline in performance over the time course of both tests indicating that retrieval speed in schizophrenia is no different from that of normal controls. Further analysis of word associations in two semantic categories (animals and body parts), revealed that deluded subjects have a more idiosyncratic organisation for animals. The findings of reduced semantic fluency production and poor logical word associations may represent a disorganised storage of semantic information in deluded patients, which in turn affects efficient access.

The planum temporale (PT) is a triangular area situated on the superior temporal gyrus (STG), which has enjoyed a resurgence of interest across several disciplines, including neurology, psychiatry and psychology. Traditionally, the planum is thought to be larger on the left side of the brain in the majority of normal subjects [N. Geschwind, W. Levitsky, Human brain: left-right asymmetries in temporal speech regions, Science 161 (1968) 186-87.]. It coincides with part of Wernicke's area and it is believed to consist cytoarchitectonically of secondary auditory cortex. Consequently, it has long been thought to be intimately involved in language function. The PT is, therefore, of relevance to disorders where language function is impaired, such as schizophrenia and dyslexia. The gross anatomical boundaries remain in dispute, and only recently has its cytoarchitecture begun to be studied again after 60 years silence, and finally its functional significance is only now being explored. In the first part of this review the structural aspects and anatomical boundaries of the PT in the normal brain from post mortem and magnetic resonance imaging (MRI) and methods of measurement are discussed. In the second part, studies of the functional significance of the PT in the normal brain are reviewed critically. Finally a meta-analysis of MRI measurements of the distribution of planum anatomy in normal subjects is presented. Comparison is made with clinical populations, including schizophrenia and dyslexia, and the influence of handedness and gender on such measurements is quantified. Although there are many ways of defining and measuring the PT with a wide variety of results, overall there is a significant leftward asymmetry in normals, which is reduced in left handers and females. The leftward asymmetry is much reduced in patients with schizophrenia due to a relatively larger right PT than normal controls. The review is intended to guide future researchers in this area.

Objective: The authors explored whether abnormal functional lateralization of temporal cortical language areas in schizophrenia was associated with a predisposition to auditory hallucinations and whether the auditory hallucinatory state would reduce the temporal cortical response to external speech., Method: Functional magnetic resonance imaging was used to measure the blood-oxygenation-level-dependent signal induced by auditory perception of speech in three groups of male subjects: eight schizophrenic patients with a history of auditory hallucinations (trait-positive), none of whom was currently hallucinating; seven schizophrenic patients without such a history (trait-negative); and eight healthy volunteers. Seven schizophrenic patients were also examined while they were actually experiencing severe auditory verbal hallucinations and again after their hallucinations had diminished., Results: Voxel-by-voxel comparison of the median power of subjects' responses to periodic external speech revealed that this measure was reduced in the left superior temporal gyrus but increased in the right middle temporal gyrus in the combined schizophrenic groups relative to the healthy comparison group. Comparison of the trait-positive and trait-negative patients revealed no clear difference in the power of temporal cortical activation. Comparison of patients when experiencing severe hallucinations and when hallucinations were mild revealed reduced responsivity of the temporal cortex, especially the right middle temporal gyrus, to external speech during the former state., Conclusions: These results suggest that schizophrenia is associated with a reduced left and increased right temporal cortical response to auditory perception of speech, with little distinction between patients who differ in their vulnerability to hallucinations. The auditory hallucinatory state is associated with reduced activity in temporal cortical regions that overlap with those that normally process external speech, possibly because of competition for common neurophysiological resources.

There have been several studies on WCST training in schizophrenia. However, it is still unclear what aspects of the test schizophrenic patients find most difficult: are they failing because of impaired attention, memory or planning, to name a few possibilities? To address this, seven different versions of the WCST were developed, including a range of alternative stimuli and training techniques. The subjects were 24 schizophrenics and 24 elderly controls, divided into eight groups of three pairs (one group merely repeating the standard version), matched on their poor performance of the WCST (< 3 categories). Results on retesting with the standard WCST after carrying out a modified version, suggest levels of test performance are not fixed, and that modifications which promote planning, pacing and error detection are the most successful in improving WCST score, especially in schizophrenics. Additionally, performance was improved in controls, but not schizophrenic patients by increasing the verbal information contained in the task. The results indicate that WCST deficits in elderly controls are due to limited capacity, whereas in patient with schizophrenia, the problem may be due to the impaired monitoring of responses.