Melbourne School of Psychological Sciences - Research Publications
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ItemCognitive and academic outcome following cranial irradiation and chemotherapy in children: a longitudinal study.(Springer Science and Business Media LLC, 2000-01)Cranial irradiation therapy (CRT) and chemotherapy are associated with neurobehavioural deficits. Many studies have investigated late effects of these treatments, but few have evaluated changes in abilities over time. This study employed a longitudinal design to map abilities following these treatments. Three groups of children were studied: Group 1 (n = 35): children treated with CRT (18 Gy) + chemotherapy, aged 5 years or less at time of diagnosis; Group 2 (n = 19): children treated with chemotherapy alone, aged 5 years or less at time of diagnosis; Group 3 (n = 35): healthy children. All children were aged 7-13 years at time of initial assessment, with no pre-diagnosis history of neurologic, developmental, or psychiatric disorder. Intellectual and educational abilities were evaluated twice: T1, not less than 2 years post-treatment, and T2, 3 years later. Group 1 achieved poorest results at T1, with comparison groups performing similarly. At T2 group differences were maintained. For verbal skills differences remained stable. Group 1 exhibited deterioration on non-verbal and processing tasks, while comparison groups showed improved abilities. Group 1 exhibited increases in literacy skills, with educational intervention predicting progress. Results suggest cumulative deficits in non-verbal and information processing skills for children treated with CRT + chemotherapy, with other deficits remaining relatively stable over time. Improved literacy skills suggest that gains can occur with remediation.
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ItemSocial cognitive determinants of ecstasy use to target in evidence-based interventions: a meta-analytical review(WILEY, 2008-01-01)AIMS: The health hazards and prevalence of ecstasy use have been documented in two decades of research, but no review reporting on potentially modifiable antecedents of use is available. The aim of this study was to integrate systematically research identifying cognitive correlates of ecstasy use. Such research has the potential to identify targets for evidence-based interventions designed to discourage use. METHODS: The databases PsycINFO and MedLine were searched, inclusion criteria applied to resulting hits, and descendency and ancestry approaches applied to the selected publications. Reported associations between cognitive determinants, including intention to use and ecstasy use measures, were synthesized by calculating a weighted mean effect size, r. RESULTS: The pattern of associations lent support both to the theory of planned behaviour (TPB) and the expectancy approach as descriptions of potentially useful determinants. Attitudes were associated most strongly with intention and use, followed by subjective norm and perceived behavioural control. CONCLUSIONS: Consideration of the strength of associations and the potential modifiability of identified cognitions suggests that evidence-based interventions to discourage ecstasy use should target negative expectancies, perceived behavioural control and anticipated regret, and consider tailoring perceived behavioural control elements.
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ItemDynamic causal modelling for EEG and MEG(SPRINGER, 2008-06-01)Dynamic Causal Modelling (DCM) is an approach first introduced for the analysis of functional magnetic resonance imaging (fMRI) to quantify effective connectivity between brain areas. Recently, this framework has been extended and established in the magneto/encephalography (M/EEG) domain. DCM for M/EEG entails the inversion a full spatiotemporal model of evoked responses, over multiple conditions. This model rests on a biophysical and neurobiological generative model for electrophysiological data. A generative model is a prescription of how data are generated. The inversion of a DCM provides conditional densities on the model parameters and, indeed on the model itself. These densities enable one to answer key questions about the underlying system. A DCM comprises two parts; one part describes the dynamics within and among neuronal sources, and the second describes how source dynamics generate data in the sensors, using the lead-field. The parameters of this spatiotemporal model are estimated using a single (iterative) Bayesian procedure. In this paper, we will motivate and describe the current DCM framework. Two examples show how the approach can be applied to M/EEG experiments.
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ItemNo Preview AvailableSchizophrenia-like psychosis and aceruloplasminemia.(Informa UK Limited, 2006-12)Schizophrenia-like illnesses occur in a variety of medical and neurological conditions but to date have not been described in association with aceruloplasminemia. Aceruloplasminemia is an autosomal recessive disorder of iron metabolism which leads to iron deposition in the basal ganglia, thalamus, cerebellum and hippocampus and which usually presents in middle age with extrapyramidal symptoms and dementia. We describe a 21-year-old woman on treatment for aceruloplasminemia who presented with schizophrenia-like psychosis and declining function in the absence of neurological signs. Neuropsychological testing showed significant dominant hemisphere deficits. Magnetic resonance imaging showed bilateral iron deposition in the cerebellar dentate nuclei and thalami, frontal atrophy, and periventricular white matter hyperintensities. Functional imaging suggested global hypoperfusion. The clinical, cognitive and imaging findings were not typical for either aceruloplasminemia or schizophrenia alone and the possible relationship between the two disorders is discussed with particular reference to implications for our understanding of schizophrenia.
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ItemNo Preview AvailableImpaired Error Awareness and Anterior Cingulate Cortex Hypoactivity in Chronic Cannabis Users(NATURE PUBLISHING GROUP, 2009-10-01)Drug abuse and other psychiatric conditions (eg, schizophrenia) have been associated with a diminished neural response to errors, particularly in the anterior cingulate cortex (ACC) thought critical to error processing. A diminished capacity for detecting errors has been linked to clinical symptoms including the loss of insight, delusions, and perseverative behavior. A total of 16 active chronic cannabis users and 16 control participants were administered a Go/No-go response inhibition task during event-related fMRI data collection. The task provides measures of inhibitory control and error awareness. Cannabis users' inhibitory control performance was equivalent to that of the control group, but the former showed a significant deficit in awareness of commission errors. Cannabis users showed a diminished capacity for monitoring their behavior that was associated with hypoactivity in the ACC and right insula. In addition, increased levels of hypoactivity in both the ACC and right insula regions were significantly correlated with error-awareness rates in the cannabis group (but not controls). These difficulties are consistent with earlier reports of hypoactivity in the neural systems underlying cognitive control and the monitoring of interoceptive awareness in chronic drug users, and highlight the potential relationship between cognitive dysfunction and behavioral deficits that have the potential to contribute to the maintenance of drug abuse.
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ItemNo Preview AvailableMeeting the support and information needs of women with advanced breast cancer: a randomised controlled trial(NATURE PUBLISHING GROUP, 2006-09-18)Addressing psychosocial and quality of life needs is central to provision of excellent care for people with advanced cancer. This study tested a brief nurse-delivered intervention to address the needs of urban women with advanced breast cancer. This study was conducted at four large urban hospitals in Australia. One hundred and five women with advanced breast cancer were recruited and randomised to receive the intervention or usual care, then asked to complete the European Organisation of Research and Treatment of Quality of life Q-C30 version (2.0) (EORTC Q-C30) (version 2) and Supportive Care Needs Survey (SCNS) at 1 month and 3 months postrecruitment. No significant differences were detected between intervention and usual care groups in the SCNS or the EORTC Q-C30 subscale scores. However, when the groups were divided into high needs (score of above 50) and low baseline needs (score of 50 or below) for each SCNS subscale, a significant difference between intervention and usual care groups was found in the psychological/emotional subscale among women with high baseline needs. In conclusions, this study demonstrated that a face-to-face session and follow-up phone call with a breast care nurse significantly reduced the psychological and emotional needs of those with high initial needs. There was no evidence of the intervention influencing the quality of life; or perceived needs of women with low initial psychological/emotional needs or perceived needs in other domains. Possibly, the intervention was not sufficiently intense to achieve an effect.
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ItemCentral Nervous System Function in Youth With Type 1 Diabetes 12 Years After Disease Onset(AMER DIABETES ASSOC, 2009-03-01)OBJECTIVE: In this study, we used neurocognitive assessment and neuroimaging to examine brain function in youth with type 1 diabetes studied prospectively from diagnosis. RESEARCH DESIGN AND METHODS: We studied type 1 diabetic (n = 106) and control subjects (n = 75) with no significant group difference on IQ at baseline 12 years previously by using the Wechsler Abbreviated Scale of General Intelligence, magnetic resonance spectroscopy and imaging, and metabolic control data from diagnosis. RESULTS: Type 1 diabetic subjects had lower verbal and full scale IQs than control subjects (both P < 0.05). Type 1 diabetic subjects had lower N-acetylaspartate in frontal lobes and basal ganglia and higher myoinositol and choline in frontal and temporal lobes and basal ganglia than control subjects (all P < 0.05). Type 1 diabetic subjects, relative to control subjects, had decreased gray matter in bilateral thalami and right parahippocampal gyrus and insular cortex. White matter was decreased in bilateral parahippocampi, left temporal lobe, and middle frontal area (all P < 0.0005 uncorrected). T2 in type 1 diabetic subjects was increased in left superior temporal gyrus and decreased in bilateral lentiform nuclei, caudate nuclei and thalami, and right insular area (all P < 0.0005 uncorrected). Early-onset disease predicted lower performance IQ, and hypoglycemia was associated with lower verbal IQ and volume reduction in thalamus; poor metabolic control predicted elevated myoinositol and decreased T2 in thalamus; and older age predicted volume loss and T2 change in basal ganglia. CONCLUSIONS: This study documents brain effects 12 years after diagnosis in a type 1 diabetic sample whose IQ at diagnosis matched that of control subjects. Findings suggest several neuropathological processes including gliosis, demyelination, and altered osmolarity.
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ItemHow does increasingly plainer cigarette packaging influence adult smokers' perceptions about brand image? An experimental study(B M J PUBLISHING GROUP, 2008-12-01)BACKGROUND: Cigarette packaging is a key marketing strategy for promoting brand image. Plain packaging has been proposed to limit brand image, but tobacco companies would resist removal of branding design elements. METHOD: A 3 (brand types) x 4 (degree of plain packaging) between-subject experimental design was used, using an internet online method, to expose 813 adult Australian smokers to one randomly selected cigarette pack, after which respondents completed ratings of the pack. RESULTS: Compared with current cigarette packs with full branding, cigarette packs that displayed progressively fewer branding design elements were perceived increasingly unfavourably in terms of smokers' appraisals of the packs, the smokers who might smoke such packs, and the inferred experience of smoking a cigarette from these packs. For example, cardboard brown packs with the number of enclosed cigarettes displayed on the front of the pack and featuring only the brand name in small standard font at the bottom of the pack face were rated as significantly less attractive and popular than original branded packs. Smokers of these plain packs were rated as significantly less trendy/stylish, less sociable/outgoing and less mature than smokers of the original pack. Compared with original packs, smokers inferred that cigarettes from these plain packs would be less rich in tobacco, less satisfying and of lower quality tobacco. CONCLUSION: Plain packaging policies that remove most brand design elements are likely to be most successful in removing cigarette brand image associations.
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ItemThe Use of the Cancellation Technique to Quantify the Hermann Grid Illusion(PUBLIC LIBRARY SCIENCE, 2007-02-28)When observers view a grid of mid-gray lines superimposed on a black background, they report seeing illusory dark gray smudges at the grid intersections, an effect known as the Hermann grid illusion. The strength of the illusion is often measured using the cancellation technique: A white disk is placed over one of these intersections and the luminance of the disk is reduced until the disk disappears. Its luminance at this point, i.e., the disk's detection threshold, is taken to be a measure of the strength of the illusion. Our experiments showed that some distortions of the Hermann grid, which were sufficient to completely disrupt the illusion, did not reduce the disk's detection threshold. This showed that the cancellation technique is not a valid method for measuring the strength of the Hermann grid illusion. Those studies that attempted to use this technique inadvertently studied a different effect known as the blanking phenomenon. We conclude by presenting an explanation for the latter effect.
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ItemAcquired disorders of reading and writing: cross-script comparisons.(Hindawi Limited, 2005)