Melbourne School of Psychological Sciences - Research Publications
Now showing items 1-12 of 509
In the context of romantic attraction, beautification can increase assertiveness in women
(PUBLIC LIBRARY SCIENCE, 2020-03-10)
Can beautification empower women to act assertively? Some women report that beautification is an agentic and assertive act, whereas others find beautification to be oppressive and disempowering. To disentangle these effects, in the context of romantic attraction we conducted the first experimental tests of beautification-on psychological and behavioral assertiveness. Experiment 1 (N = 145) utilized a between-subjects design in which women used their own clothing, make-up, and accessories to adjust their appearance as they normally would for a "hot date" (beautification condition) or a casual day at home with friends (control condition). We measured implicit, explicit, and behavioral assertiveness, as well as positive affect and sexual motivation. Experiment 2 (N = 40) sought to conceptually replicate Experiment 1 using a within-subject design and different measures of assertiveness. Women completed measures of explicit assertiveness and assertive behavioral intentions in three domains, in whatever clothing they were wearing that day then again after extensively beautifying their appearance. In Experiment 1, we found that women demonstrated higher psychological assertiveness after beautifying their appearance, and that high sexual motivation mediated the effect of beautification on assertive behavior. All effects were independent of positive affect. Experiment 2 partially replicated Experiment 1. These experiments provide novel insight into the effects of women's appearance-enhancing behaviors on assertiveness by providing evidence that beautification may positively affect assertiveness in women under some circumstances.
The evolution of extreme cooperation via shared dysphoric experiences!
(NATURE PUBLISHING GROUP, 2017-03-14)
Willingness to lay down one's life for a group of non-kin, well documented historically and ethnographically, represents an evolutionary puzzle. Building on research in social psychology, we develop a mathematical model showing how conditioning cooperation on previous shared experience can allow individually costly pro-group behavior to evolve. The model generates a series of predictions that we then test empirically in a range of special sample populations (including military veterans, college fraternity/sorority members, football fans, martial arts practitioners, and twins). Our empirical results show that sharing painful experiences produces "identity fusion" - a visceral sense of oneness - which in turn can motivate self-sacrifice, including willingness to fight and die for the group. Practically, our account of how shared dysphoric experiences produce identity fusion helps us better understand such pressing social issues as suicide terrorism, holy wars, sectarian violence, gang-related violence, and other forms of intergroup conflict.
Sustained attention, attentional selectivity, and attentional capacity across the lifespan
Changes in sustained attention, attentional selectivity, and attentional capacity were examined in a sample of 113 participants between the ages of 12 and 75. To measure sustained attention, we employed the sustained-attention-to-response task (Robertson, Manly, Andrade, Baddeley, & Yiend, Neuropsychologia 35:747-58, 1997), a short continuous-performance test designed to capture fluctuations in sustained attention. To measure attentional selectivity and capacity, we employed a paradigm based on the theory of visual attention (Bundesen, Psychological Review 97:523-547, 1990), which enabled the estimation of parameters related to attentional selection, perceptual threshold, visual short-term memory capacity, and processing capacity. We found evidence of age-related decline in each of the measured variables, but the declines varied markedly in terms of magnitude and lifespan trajectory. Variables relating to attentional capacity showed declines of very large effect sizes, while variables relating to attentional selectivity and sustained attention showed declines of medium to large effect sizes, suggesting that attentional control is relatively preserved in older adults. The variables relating to sustained attention followed a U-shaped, curvilinear trend, and the variables relating to attentional selectivity and capacity showed linear decline from early adulthood, providing further support for the differentiation of attentional functions.
Pervasive White Matter Fiber Degeneration in Ischemic Stroke
(LIPPINCOTT WILLIAMS & WILKINS, 2020-05-01)
Background and Purpose- We examined if ischemic stroke is associated with white matter degeneration predominantly confined to the ipsi-lesional tracts or with widespread bilateral axonal loss independent of lesion laterality. Methods- We applied a novel fixel-based analysis, sensitive to fiber tract-specific differences within a voxel, to assess axonal loss in stroke (N=104, 32 women) compared to control participants (N=40, 15 women) across the whole brain. We studied microstructural differences in fiber density and macrostructural (morphological) changes in fiber cross-section. Results- In participants with stroke, we observed significantly lower fiber density and cross-section in areas adjacent, or connected, to the lesions (eg, ipsi-lesional corticospinal tract). In addition, the changes extended beyond directly connected tracts, independent of the lesion laterality (eg, corpus callosum, bilateral inferior fronto-occipital fasciculus, right superior longitudinal fasciculus). Conclusions- We conclude that ischemic stroke is associated with extensive neurodegeneration that significantly affects white matter integrity across the whole brain. These findings expand our understanding of the mechanisms of brain volume loss and delayed cognitive decline in stroke.
Effective brain connectivity at rest is associated with choice-induced preference formation.
Preferences can change as a consequence of making a hard decision whereby the value of chosen options increases and the value of rejected options decreases. Such choice-induced preference changes have been associated with brain areas detecting choice conflict (anterior cingulate cortex, ACC), updating stimulus value (dorsolateral prefrontal cortex, dlPFC) and supporting memory of stimulus value (hippocampus and ventromedial prefrontal cortex, vmPFC). Here we investigated whether resting-state neuronal activity within these regions is associated with the magnitude of individuals' preference updates. We fitted a dynamic causal model (DCM) to resting-state neuronal activity in the spectral domain (spDCM) and estimated the causal connectivity among core regions involved in preference formation following hard choices. The extent of individuals' choice-induced preference changes were found to be associated with a diminished resting-state excitation between the left dlPFC and the vmPFC, whereas preference consistency was related to a higher resting-state excitation from the ACC to the left hippocampus and vmPFC. Our results point to a model of preference formation during which the dynamic network configurations between left dlPFC, ACC, vmPFC and left hippocampus at rest are linked to preference change or stability.
The Decision Decoding ToolBOX (DDTBOX) - A Multivariate Pattern Analysis Toolbox for Event-Related Potentials
(HUMANA PRESS INC, 2019-01-01)
In recent years, neuroimaging research in cognitive neuroscience has increasingly used multivariate pattern analysis (MVPA) to investigate higher cognitive functions. Here we present DDTBOX, an open-source MVPA toolbox for electroencephalography (EEG) data. DDTBOX runs under MATLAB and is well integrated with the EEGLAB/ERPLAB and Fieldtrip toolboxes (Delorme and Makeig 2004; Lopez-Calderon and Luck 2014; Oostenveld et al. 2011). It trains support vector machines (SVMs) on patterns of event-related potential (ERP) amplitude data, following or preceding an event of interest, for classification or regression of experimental variables. These amplitude patterns can be extracted across space/electrodes (spatial decoding), time (temporal decoding), or both (spatiotemporal decoding). DDTBOX can also extract SVM feature weights, generate empirical chance distributions based on shuffled-labels decoding for group-level statistical testing, provide estimates of the prevalence of decodable information in the population, and perform a variety of corrections for multiple comparisons. It also includes plotting functions for single subject and group results. DDTBOX complements conventional analyses of ERP components, as subtle multivariate patterns can be detected that would be overlooked in standard analyses. It further allows for a more explorative search for information when no ERP component is known to be specifically linked to a cognitive process of interest. In summary, DDTBOX is an easy-to-use and open-source toolbox that allows for characterising the time-course of information related to various perceptual and cognitive processes. It can be applied to data from a large number of experimental paradigms and could therefore be a valuable tool for the neuroimaging community.
Rivalry Onset in and around the Fovea: The Role of Visual Field Location and Eye Dominance on Perceptual Dominance Bias.
(MDPI AG, 2019-09-30)
When dissimilar images are presented to each eye, the images will alternate every few seconds in a phenomenon known as binocular rivalry. Recent research has found evidence of a bias towards one image at the initial 'onset' period of rivalry that varies across the peripheral visual field. To determine the role that visual field location plays in and around the fovea at onset, trained observers were presented small orthogonal achromatic grating patches at various locations across the central 3° of visual space for 1-s and 60-s intervals. Results reveal stronger bias at onset than during continuous rivalry, and evidence of temporal hemifield dominance across observers, however, the nature of the hemifield effects differed between individuals and interacted with overall eye dominance. Despite using small grating patches, a high proportion of mixed percept was still reported, with more mixed percept at onset along the vertical midline, in general, and in increasing proportions with eccentricity in the lateral hemifields. Results show that even within the foveal range, onset rivalry bias varies across visual space, and differs in degree and sensitivity to biases in average dominance over continuous viewing.
Predicting Temperamentally Inhibited Young Children's Clinical-Level Anxiety and Internalizing Problems from Parenting and Parent Wellbeing: a Population Study
(SPRINGER/PLENUM PUBLISHERS, 2019-07-01)
The aim of this study was to explore how some temperamentally inhibited young children and not others in the general population develop anxiety disorders and broader clinical-level internalizing (anxious/depressive) problems, with a focus on the family. A brief screening tool for inhibition was universally distributed to parents of children in their year before starting school across eight socioeconomically diverse government areas in Melbourne, Australia (307 preschool services). Screening identified 11% of all children as inhibited. We invited all parents of inhibited children to participate in a longitudinal prevention study. Participants were 545 parents of inhibited pre-schoolers (78% uptake) of whom 498 (91%) completed assessment one year later and 469 (86%) two years later. Parents completed questionnaires to assess parenting practices, parent wellbeing, and child internalizing problems. Parents also engaged in structured diagnostic interviews to assess child anxiety disorders. During the follow up period close to half of the inhibited young children had anxiety disorders and one in seven had clinical-level internalizing problems, with girls perhaps at higher risk. The family variables significantly predicted inhibited children's anxiety disorders and broader internalizing problems. For child anxiety disorders, overinvolved/protective parenting was particularly important for girls and boys, and poorer parent wellbeing contributed. For child anxious/depressive problems, harsh discipline was a consistent predictor for girls and boys, and poorer parent wellbeing again contributed. These etiological findings support early intervention for temperamentally inhibited young children that focuses on the family environment to prevent the development of mental health problems.
The Stroke and Carer Optimal Health Program (SCOHP) to enhance psychosocial health: study protocol for a randomised control trial
(BioMed Central, 2016)
Background: Stroke is a leading cause of disability and distress, and often profoundly affects the quality of life of stroke survivors and their carers. With the support of carers, many stroke survivors are returning to live in the community despite the presence of disability and ongoing challenges. The sudden and catastrophic changes caused by stroke affects the mental, emotional and social health of both stroke survivors and carers. The aim of this study is to evaluate a Stroke and Carer Optimal Health Program (SCOHP) that adopts a person-centred approach and engages collaborative therapy to educate, support and improve the psychosocial health of stroke survivors and their carers. Methods: This study is a prospective randomised controlled trial. It will include a total of 168 stroke survivors and carers randomly allocated into an intervention group (SCOHP) or a control group (usual care). Participants randomised to the intervention group will receive nine (8 + 1 booster) sessions guided by a structured workbook. The primary outcome measures for stroke survivors and carers will be health-related quality of life (AQoL-6D and EQ-5D) and self-efficacy (GSE). Secondary outcome measures will include: anxiety and depression (HADS); coping (Brief COPE); work and social adjustment (WSAS); carer strain (MCSI); carer satisfaction (CASI); and treatment evaluation (TEI-SF and CEQ). Process evaluation and a health economic cost analysis will also be conducted. Discussion: We believe that this is an innovative intervention that engages the stroke survivor and carer and will be significant in improving the psychosocial health, increasing independence and reducing treatment-related costs in this vulnerable patient-carer dyad. In addition, we expect that the intervention will assist carers and stroke survivors to negotiate the complexity of health services across the trajectory of care and provide practical skills to improve self-management.
Design and protocol for the Dialysis Optimal Health Program (DOHP) randomised controlled trial
BACKGROUND: Chronic kidney disease (CKD) and end-stage kidney disease (ESKD) are serious and growing health problems with enormous impact on psychological and social functioning. Despite high rates of comorbid depression and anxiety in these patient populations, and the adverse impact these have upon treatment adherence, quality of life, social connectedness and healthcare costs there has been little attention focused on the prevention or management of these problems. Thus, our aim was to evaluate the Dialysis Optimal Health Program (DOHP) that adopts a person-centred approach and engages collaborative therapy to educate and support those diagnosed with ESKD who are commencing dialysis. METHODS: The study design is a randomised controlled trial. Ninety-six adult patients initiating haemodialysis or peritoneal dialysis will be randomly allocated to either the intervention (DOHP) or usual care group. Participants receiving the intervention will receive nine (8 + 1 booster session) sequential sessions based on a structured information/workbook, psychosocial and educational supports and skills building. The primary outcome measures are depression and anxiety (assessed by the Hospital Anxiety and Depression Scale; HADS). Secondary outcomes include health-related quality of life (assessed by the Kidney Disease Quality of Life instrument; KDQOL), self-efficacy (assessed by General Self-Efficacy Scale) and clinical indices (e.g. albumin and haemoglobin levels). Cost-effectiveness analysis and process evaluation will also be performed to assess the economic value and efficacy of the DOHP. Primary and secondary measures will be collected at baseline and at 3-, 6-, and 12-month follow-up time points. DISCUSSION: We believe that this innovative trial will enhance knowledge of interventions aimed at supporting patients in the process of starting dialysis, and will broaden the focus from physical symptoms to include psychosocial factors such as depression, anxiety, self-efficacy, wellbeing and community support. The outcomes associated with this study are significant in terms of enhancing an at-risk population's psychosocial health and reducing treatment-related costs and associated pressures on the healthcare system. TRIAL REGISTRATION: ANZCTR no. 12615000810516 . Registered on 5 August 2015.
The use of formal criteria to assess psychological models of hallucinations: a systematic review
(Taylor & Francis (Routledge), 2019-06-03)
Objectives: Our aim was to explore the application of systematic criteria proposed by Bentall, Corcoran, Howard, Black and Kinderman (2001) to determine whether they are helpful in determining the quality of psychological models, which are used to develop and guide treatment. Method: We chose to conduct a systematic review of models of hallucinations. PsycINFO, MEDLINE and PubMED were used to identify relevant articles. Each model was classified as a high, medium or low level of fit with the criteria. Results: Nineteen models met the inclusion criteria. Two models were a high level of fit, twelve a medium level of fit while the rest were a low level of fit. Some difficulties were encountered applying the criteria and are discussed. Conclusions: Bentall et al.’s (2001) criteria proved useful. Frith’s (2015) and Hoffman’s (1986) models were deemed the best level of fit. The role of self-monitoring and language-production processes in hallucination formation may merit further investigation. There is an outstanding need for international standardized guidelines to advance the quality of psychological models to assist the design and delivery of more effective interventions.
Can antipsychotic dose reduction lead to better functional recovery in first-episode psychosis? A randomized controlled-trial of antipsychotic dose reduction. The reduce trial: Study protocol
Antipsychotic medication has been the mainstay of treatment for psychotic illnesses for over 60 years. This has been associated with improvements in positive psychotic symptoms and a reduction in relapse rates. However, there has been little improvement in functional outcomes for people with psychosis. At the same time there is increasing evidence that medications contribute to life shortening metabolic and cardiovascular illnesses. There is also uncertainty as to the role played by antipsychotic medication in brain volume changes. AIM: The primary aim of the study is, in a population of young people with first-episode psychosis, to compare functional outcomes between an antipsychotic dose reduction strategy with evidence-based intensive recovery treatment (EBIRT) group (DRS+) and an antipsychotic maintenance treatment with EBIRT group (AMTx+) at 24-months follow-up. METHODS: Our single-blind randomized controlled trial, within a specialist early psychosis treatment setting, will test the whether the DRS+ group leads to better vocational and social recovery than, the AMTx+ group over a 2-year period in 180 remitted first-episode psychosis patients. Additionally, we will examine the effect of DRS+ vs AMTx+ on physical health, brain volume and cognitive functioning. This study will also determine whether the group receiving DRS+ will be no worse off in terms of psychotic relapses over 2 years follow-up. RESULTS: This paper presents the protocol, rationale and hypotheses for this study which commenced recruitment in July 2017. CONCLUSION: This study will provide evidence as to whether an antipsychotic dose-reduction recovery treatment leads to improved functioning and safer outcomes in first-episode psychosis patients. In addition, it will be the first-controlled experiment of the effect of exposure to antipsychotic maintenance treatment on brain volume changes in this population.