Susan Rossell

Emotional prosodic processing in auditory hallucinations

Deficits in emotional prosodic processing, the expression of emotions in voice, have been widely reported in patients with schizophrenia, not only in comprehending emotional prosody but also expressing it. Given that prosodic cues are important in memory for voice and speaker identity, Cutting has proposed that prosodic deficits may contribute to the misattribution that appears to occur in auditory hallucinations in psychosis. The present study compared hallucinating patients with schizophrenia, non-hallucinating patients and normal controls on an emotional prosodic processing task. It was hypothesised that hallucinators would demonstrate greater deficits in emotional prosodic processing than non-hallucinators and normal controls. Participants were 67 patients with a diagnosis of schizophrenia or schizoaffective disorder (hallucinating=38, non-hallucinating=29) and 31 normal controls. The prosodic processing task used in this study comprised a series of semantically neutral sentences expressed in happy, sad and neutral voices which were rated on a 7-point Likert scale from sad (-3) through neutral (0) to happy (+3). Significant deficits in the prosodic processing tasks were found in hallucinating patients compared to non-hallucinating patients and normal controls. No significant differences were observed between non-hallucinating patients and normal controls. In the present study, patients experiencing auditory hallucinations were not as successful in recognising and using prosodic cues as the non-hallucinating patients. These results are consistent with Cuttings hypothesis, that prosodic dysfunction may mediate the misattribution of auditory hallucinations.

Category fluency performance in patients with schizophrenia and bipolar disorder: The influence of affective categories.

Semantic fluency (SF) and phonological fluency (PF) were examined in large groups of schizophrenia patients, bipolar patients and controls. As well as standard SF categories (animals and food), fluency to two affective categories, happy and fear was measured, i.e. participants were asked to produce as many words as they could that resulted in or are associated with fear or happiness. Schizophrenia patients showed SF and PF deficits. Bipolar patients showed PF deficits. Thus, PF is argued to be a good cognitive marker in both disorders. Severity of delusions was related to SF performance in all patients. The patient groups showed different patterns on the affective categories compared to controls: the bipolar patients were better and produced more words, especially to the happiness category, and the schizophrenia patients were impaired and produced less words. The results suggest an interesting interaction between psychotic illnesses, fluency and emotion.

Semantic Priming after Ketamine Acutely in Healthy Volunteers and Following Chronic Self-Administration in Substance Users

BACKGROUNDnKetamine is used acutely as a model of schizophrenia. It has been suggested that chronic ketamine may also mimic aspects of this disorder, in particular impaired cognitive function. As semantic processing deficits are considered central to cognitive impairments in schizophrenia, this study aimed to characterize semantic impairments following both acute and chronic ketamine.nnnMETHODSnWe examined the acute effects of two doses of ketamine (Experiment 1) using a double-blind, placebo-controlled, independent group design with 48 volunteers. Ketamines chronic effects (Experiment 2) were explored in 16 ketamine users and 16 poly-drug controls. A semantic priming task with a frequency (high and low) and stimulus onset asynchrony (SOA: short-200 msec, long-750 msec) manipulation was used.nnnRESULTSnIn Experiment 1, acute ketamine produced inverse priming at the long SOA. In Experiment 2, ketamine users showed inverse priming for low-frequency words at the long SOA compared to poly-drug controls.nnnCONCLUSIONSnThe inverse priming effect at the long SOA induced by acute ketamine was indicative of controlled processing impairments. In ketamine users, there was also an indication of controlled processing impairments. Decreased priming for low-frequency words suggested that long-term ketamine abuse results in damage to the semantic store.

Use of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to investigate group and gender differences in schizophrenia and bipolar disorder

Objective: Gender differences exist in schizophrenia and bipolar disorder (BD), therefore the aim of the present study was to clarify the role of gender in cognitive deficits in these disorders. Methods: Cognitive performance was examined in schizophrenia (24M: 14F) and BD (16M: 24F) patients compared with age-, IQ- and gender-matched control participants (21M: 22F). The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess five cognitive domains: immediate memory/learning, visuospatial ability, language, attention, and delayed memory, which are summed to provide a Total score. Results: In comparison to controls, schizophrenia patients showed deficits on all domains, while BD patients had impaired immediate memory/learning, language and Total score. Schizophrenia patients showed deficits compared to BD in the Total score, immediate and delayed memory and visuospatial ability. The Total and domain scores were not different in men and women across or within groups. There were gender effects on four of the 12 individual cognitive tasks, in which female patients outperformed male patients. Further, there were gender differences across groups for three of the individual tasks: female schizophrenia patients showed poorer story memory and story recall compared to male schizophrenia patients; female BD patients had enhanced figure copy performance compared to male BD patients. Conclusions: The RBANS highlighted the cognitive deficits in schizophrenia and BD patients compared to controls and also each other. There were no overall gender differences in cognition.

Functional connectivity estimation in fMRI data: influence of preprocessing and time course selection

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. Hum Brain Mapp 2008.

Evidence of semantic disorganisation using semantic priming in individuals with high schizotypy

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 examination of delusional thinking and cognitive styles in body dysmorphic disorder

Objective: Body dysmorphic disorder (BDD) is characterized by severe dissatisfaction with ones appearance. The aim of this study was to examine belief characteristics in BDD, particularly delusional beliefs and their relationship to other cognitive styles. Methods: Fourteen DSM-IV BDD patients and 14 matched control participants completed questionnaires that measured delusions, creative experiences, self-esteem, self-ambivalence, depression and anxiety symptoms. Results: BDD patients endorsed three times as many delusional beliefs as controls, but the number of delusional ideas in the BDD sample was on a continuum and did not divide patients into two discrete groups. Additionally, the BDD group had higher fantasy proneness, lower self-esteem, higher self-ambivalence and higher depression and anxiety. Conclusions: The data support the conceptualization of BDD as a single disorder with varying degrees of delusional thinking and suggests that BDD should not be dichotomized according to the presence or absence of delusional thinking, as is currently the case in the DSM-IV.

Can understanding the neurobiology of body dysmorphic disorder (BDD) inform treatment

Objectives: We aim to provide a clinically focused review of the neurobiological literature in body dysmorphic disorder (BDD), with a focus on structural and functional neuroimaging. Conclusions: There has been a recent influx of studies examining the underlying neurobiology of BDD using structural and functional neuroimaging methods. Despite obvious symptom similarities with obsessive–compulsive disorder (OCD), no study to date has directly compared the two groups using neuroimaging techniques. Studies have established that there are limbic and visual cortex abnormalities in BDD, in contrast to fronto-striatal differences in OCD. Such data suggests affect or visual training maybe useful in BDD.

Behavioural and fMRI evidence of semantic category deficits in schizophrenia

Background: Abnormalities in semantic processing are commonly proposed to be central to cognitive abnormalities and thought disturbances in schizophrenia. Defi cits have been reported on a range of tasks including a categorization task. The current study investigated the underlying neural substrates involved during categorization. Method: A revised version of Chen et al.’s (1994) categorization task was used. The task consisted of 18 categories with fi ve different exemplar words (ie high frequency, low frequency, borderline, related but outside category and unrelated) selected for each category. Subjects were asked to say whether exemplars were or were not part of the category. Data for each exemplar type were examined; this included behavioural accuracy and an event-related analysis of the functional magnetic resonance imaging data using SPM2. Results: Behaviourally, patients with schizophrenia had diffi culty categorizing related words, while the controls had most diffi culty with borderline examples. Performance in the controls was related to activity in the left inferior frontal, left inferior occipital/posterior temporal, bilateral precunues and the cerebellum; areas typically reported during semantic processing. Even when behavioural performance on some of the category types was no different to control performance, the patients with schizophrenia did not show any activation of this network. Conclusions: The imaging data showed impairments in the distributed frontal temporal network that is engaged in the representation and processing of meaning of words, text and discourse. It is these abnormalities that may underlie schizophrenic thought disturbance. Jumping to conclusions in delusions: fact or fallacy?

Using the semantic priming task in schizophrenia research: methodological and theoretical considerations.

307 identifi ed. Quantitative and qualitative data show that the program was equally effective for Aboriginal and non-Aboriginal students. Furthermore, participants identifi ed changes in their relationships with young people in the classroom subsequent to the program’s implementation. Conclusions: There is a need to ensure that resilience programs are adapted to enhance their cultural safety and relevance. To articulate the impact of adapted programs, mixed methodologies are essential.