Melbourne School of Psychological Sciences - Theses
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ItemUsing long-wear electroencephalography to ascertain the variability of Lempel-Ziv Complexity (LZc) measures of consciousness( 2019)It has been recently claimed that measures of spontaneous electroencephalography (EEG) signal complexity, such as Lempel-Ziv Complexity (LZc), can provide an index of an individual’s level of consciousness. Research and clinical practice are currently limited to unreliable behavioural and physiological measures to indicate consciousness. Therefore, there is significant urgency for an objective, reliable, brain-based measure of consciousness. EEG complexity measures utilise algorithms from Information Theory to quantify the diversity in spontaneous EEG data. These are being used to measure the diverse neural activity which necessarily underlies conscious experience. LZc assesses the complexity of multi-channel EEG data using a compression algorithm. Studies of LZc typically involve comparing conditions of altered consciousness with periods of conscious wakefulness. These studies suggest that the change in complexity observed is reflective of the change in level of consciousness. However, very little is known about how LZc varies, either with or without a corresponding change in consciousness. The present study utilised portable long-wear EEG to record multi-day, continuous EEG data from two participants (a total of 8 days for Participant 1 and 4 days for Participant 2). Data from each participant was analysed independently. A LZc algorithm was used to compute a complexity value for every non-overlapping 10-second segment. Results demonstrated that, as with previous research, LZc during Wake (14-hours during the day, multiple days per participant) is, on average, higher than during sleep (Stage N1, Stage N2, Slow-Wave-Sleep, and REM sleep). However, there is considerable variation surrounding these means. Visualising LZc across Wake revealed a consistent but wide spread of variability around the mean, with a scattering of low LZc values reflected by a negative skew in the data. This also results in a wide range of possible mean LZc values made available from taking samples (between 1 and 120 minutes in duration) during this period. Although this variability reduces with larger samples sizes, even day-to-day, LZc can significantly differ within a person. Regardless of the source of this variability, its presence causes concern due to the overarching clinical motivations and potential practical applications of this measure. These results suggest that LZc may not be indicative of level of consciousness, as previously claimed. The issues raised and addressed in this study are not unique to LZc, but will apply to all complexity algorithms, current and future. With this study, we have shown that long-duration EEG is a successful framework for identifying variability in a complexity measure of consciousness. This information-rich dataset is uniquely capable of exposing and investigating complexity measures, with the additional insight of observing and analysing complexity across time. This study endeavours to redirect discussions of this field and promote the use of this framework to both acknowledge and empirically address all surrounding issues and assumptions. All complexity measures should undergo reliability testing as both a proof of concept and a proof of practice before being utilised in research or clinical applications.
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ItemUsing single subject manual independent component analysis on resting-state fMRI data( 2019)It is important to understand the influence of common artefacts when processing fMRI data, and how best to remove these in order to produce reliable outcomes. This information affects clinicians and researchers. Little is known about functional connectivity in people with genetic generalised epilepsy at present, making it an ideal cohort to examine while using a quality data processing pipeline. The present thesis discusses individual artefactual contribution, and how to deal with artefact using single subject manual independent component analysis (SSM-ICA). A systematic review of the literature (Chapter two) found people with genetic generalised epilepsy to have reduced functional connectivity in the default mode and attention networks relative to healthy controls. A methods study (Chapter three) investigated functional connectivity in juvenile absence epilepsy, a subtype of genetic generalised epilepsy. Results showed reduced connectivity strength relative to controls. Further, incremental removal of artefacts using single subject manual independent component analysis showed fewer correlations breaching the .05 threshold. These areas were more confined to default mode and attention networks, suggesting most correlations derived without the use of SSM-ICA are spurious. Signal-to-noise ratios were also significantly higher in both incremental cleaning conditions.
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ItemEarly maladaptive schemas associated with performance anxiety aetiology and phenomenology in classically-trained musicians( 2018)Music performance anxiety (MPA) is widespread amongst performing musicians, although research into developmental factors involved in its manifestation is minimal. The aim of this research was to explore the impact of childhood experiences with parents along with patterns of dysfunctional cognitive schemas that develop through childhood (‘Early Maladaptive Schemas’; EMSs) on the manifestation and severity of MPA in adulthood. Study 1 investigated the relationship between EMSs and MPA through online surveys. Study 2 then expanded on Study 1 by exploring childhood parenting experiences associated with the development of both EMSs and MPA through qualitative interviews. Study 1 employed 100 adult professional, amateur, and student classical musicians from across Australia (recruited via email and social media). Participants completed the Young Schema Questionnaire (Young, 2005) and the Kenny Music Performance Anxiety Inventory (Kenny, 2011). Factor analysis revealed four higher-order EMS factors, one of which was a significant predictor of MPA. This factor (entitled ‘Inadequacy/Impaired Autonomy’) comprised themes of failure, catastrophising, and incompetence/dependence. Study 2 included eight participants from Study 1, five of whom scored one standard deviation or more above the mean K-MPAI score and three of whom scored one standard deviation or more below the mean K-MPAI score. Participants were interviewed about experiences of parenting during childhood and adolescence, along with their experiences of MPA and musical training. Interpretative phenomenological analysis was used to explore themes in the interview data, which revealed three key parenting styles related to the development of MPA: Poor Parental Involvement and Availability, Unpredictable Parental Mood and Anger, and Parental Expectations and Overcontrol. Findings from both studies are discussed in light of clinical applications and interventions, and implications for both parents and music educators.
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ItemA psychometric evaluation of the Temporal Experience of Pleasure Scales (TEPS)( 2014)A number of hypotheses for behaviour are built on the principle of “hedonic motivation”, the assumption that people are always motivated towards rewards that affords them with the greatest amount of pleasure. Current neurobiological studies have demonstrated that reward-motivational processes and hedonic processes are mediated by independent systems (Dillon et al., 2008). Salient rewards activate the production and attribution of incentive salience by the mesocorticolimbic dopaminergic system, which promotes reward-motivation or ‘wanting’ towards preferred rewards (Berridge, Robinson, & Aldridge, 2009). The attainment of rewards is marked by the experience of pleasure or ‘liking’, which is mediated by the attribution of hedonic gloss to this event by the forebrain opioidergic system (Pecina, Cagniard, Berridge, Aldridge, & Zhuang, 2003). The Incentive Salience Theory (IST) argues against the hedonic principle, maintaining that these two reward-related processes are dissociated, such that the loss or increase in reward ‘liking’ does not affect reward ‘wanting’, and vice-versa (Robinson & Berridge, 2001). The Temporal Experience of Pleasure Scales (TEPS; Gard, Gard, Kring, John, 2006) is the first self-report questionnaire that is designed to assess individual differences in the ability to experience dopaminergic-mediated anticipatory pleasure and opioidergic-mediated consummatory pleasure. However, the psychometric structure of the TEPS has not been fully evaluated, providing the goal of the current study to conduct a psychometric analysis consisting of a factor analysis and construct validation by a convergent-discriminant analysis. While the formation of two distinct subscales in the scale construction study and demonstrating predictive validity with schizophrenia (Gard, Kring, Gard, Horan, & Green, 2007), the two scales lacked clear dissociation and its relationship with schizophrenia has not been consistently observed (Strauss, Wilbur, Warren, August, & Gold, 2011). Two hundred and ninety-two university students in Australia (212 females, 80 males, Mage = 20.19 years, SD = 4.24, age range: 18-53) and 292 university students in the United Kingdom (226 females, 66males, Mage =20.96 years, SD = 4.72, age range: 18-44) completed the TEPS, which required the participant to report the amount of anticipation (anticipatory subscale) or in-the-moment pleasure (consummatory subscale) they would experience in response to hypothetical rewarding experiences. The Australian participants also completed a battery of conceptually-related self-report questionnaires. Given past lack of support, it was not surprising that the two-factor model of the TEPS was unsupported by the current factor analysis. On a similar note, construct validity was unsupported as the lack of discriminant validity with measures of reward-motivation and positive emotionality meant that the two subscales cannot be assumed to be dissociated measures of ‘wanting’ and ‘liking’. In light of these findings, it might be suggested that the assessment of these two reward-related processes by hypothetical self-report is difficult as humans may not be able to think of something pleasurable without also desiring it, and vice-versa (Berridge, 2007). Further limitations of self-reports include the fallibility of autobiographic memory and of affective forecasting (Wilson & Gilbert, 2005). Future studies should consider alternative assessment methods of ‘wanting’ and ‘liking’ that are less reliant on affective forecasting, such as ambulatory affective state assessments and implicit indexes whereas behavioural indexes are highly recommended for their proximity to reality and minimal reliance on conscious deliberation.
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ItemNeuropsychological and computed tomography findings in two subgroups of schizophrenia( 1986)The group of disorders collectively referred to as schizophrenia, have traditionally been conceptualized as functional psychoses in which primary cognitive functions are unimpaired. Despite this, a proportion of schizophrenic patients have long been known to perform poorly on tests of cognitive function and some proceed to an end state resembling organic dementia. The application of CT scans in the last decade to the schizophrenic population, has revealed that some schizophrenic patients have abnormal brain morphology. Changes in brain morphology have also been correlated with cognitive impairment and defect (negative) symptoms. On the basis of these findings two subgroups of schizophrenia have been proposed. Type I schizophrenia is hypothesized to be characterized by normal brain morphology, normal cognition and florid (positive) symptoms. Type II schizophrenia is hypothesized to be characterized by abnormal brain morphology, impaired cognition and predominantly defect (negative) symptoms. Despite the heuristic value of this hypothesis, research was impeded by the lack of valid techniques for the measurement of positive and negative symptoms. Recent reports have provided such measurement scales, however these have not been widely used to specifically investigate CT scan findings and cognitive impairment in schizophrenic patients. This is the report of an investigation which aimed to examine the relationship between positive and negative symptoms, CT scan findings and performance on a wide range of neuropsychological tests known to be sensitive to the effects of localized cerebral disruption in neurological patients 1 in a group of schizophrenic patients. The results suggest that patients with severe negative symptoms have localized cerebral atrophy of the frontal regions of the brain and are impaired on tests of frontal lobe function. These findings support the hypothesis of different subgroups of schizophrenia, in which the underlying aetiology of one subgroup, may be organic in nature.
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ItemWhat are the special characteristics of families who provide long term care for children of parents with mental illness?( 2003)This project investigated characteristics relating to family functioning and attitudes to mental illness, and caregiving, which distinguish families choosing to care for children of parents with mental illness (CPMI) from families who choose not to but do care for other children (NCPMI), and from families not involved in the adoptive care system (COMM). Welfare agencies seeking long term home based care for children of parents with mental illness (among other groups of children) report that potential caregivers are concerned about the child’s genetic risk, and the requirement that they facilitate access visits with the birth parent. Consequently it is more difficult to recruit caregivers to care for children of parents with mental illness. Previous studies found that families who adopt children with special needs had family systems that were flexible and able to adapt to changing needs, and in which family members felt close to one another. It was not known if the functioning of families who care for children of parents with mental illness would differ from other family groups. Nor was it known if these families would differ in motivation to be caregivers and attitudes to mental illness from other family groups. Forty four families completed a questionnaire providing background information, and a family functioning questionnaire which included the FACES II measure (Family Adaptability and Cohesion Evaluation Scale) and questions assessing level of altruism, and tendency to respond in a socially desirable manner. Data from the FACES II measure was used to classify families according to the Circumplex Model of Marital and Family Systems. Q-methodology was used to assess participants’ attitudes to eight issues related to the research question: mental illness, children of parents with mental illness, parents having a mental illness, family environment, motivation to be caregivers, ongoing contact between child in care and parent, approval of others when deciding to be a caregiver, and flexibility in deciding to accept a certain child for placement. The Q-method required participants to rate 42 statements (a Q-set), concerning these issues, according to a fixed distribution, from statements with which they strongly agreed to statements with which they strongly disagreed. Participants could also give open-ended responses to questions addressing the same issues in a semi-structured interview. The CPMI group were found to have a lower level of income and education than the other two groups, and were more likely to be full time caregivers. Both caregiver groups were unlikely to have children of their own. The profiles of the three groups on the cohesion and flexibility sub-scales of FACES II were similar. The classification of the family groups on the Circumplex model showed that the CPMI group were located in the balanced and mid-range levels of the model more so than the other two groups. Responses to the Q-sort and interview questions suggested that the CPMI families were more understanding of mental illness, and of the needs of the children and capacity of their parents. It is suggested that future studies increase the number of participants, and investigate in more detail the factors which motivate families who provide long term care for children of parents with mental illness.
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ItemThe assessment and treatment of concerns and anxiety in patients undergoing pre-surgical monitoring for epilepsy( 2006)The aim of the present study was to investigate the efficacy of an information package on reducing pre-surgical anxiety and concerns in patients with intractable epilepsy. Adverse psychological and social effects of temporal lobe epilepsy (TLE) are instrumental in anxiety and distress in these patients. This is brought into the hospital setting and exacerbated by the monitoring process and concomitant possibility of surgery where many patients prematurely curtailed the process at cost to themselves and the hospital.
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ItemAn investigation of forecasting behaviour( 2002)To manage an uncertain future relevant societal groups, such as government and corporate sectors, utilise economic forecasts to help plan future strategies. Many vital decisions are based on economic forecasts. Economists have traditionally been the professionals employed as economic forecasting experts. The dominant paradigm for present day forecasting is the "rational expectations theory", which assumes that a forecaster is capable of making optimal use all of the available information. The field of psychology offers a different, yet complementary, approach to the topic of economic forecasting. The aim of the current study was to research mental processes and behaviours of individuals participating in a forecasting task. The role of the following psychological variables within economic prediction behaviour was assessed: (1) task complexity, (2) decision making style, (3) the anchoring and adjustment heuristic, (4) the framing effect, and (5) personal feelings about the task content. All of these variables were hypothesised to have a direct influence on prediction behaviour. In addition, task complexity and decision making style were assumed to moderate the influence of the other psychological variables. A conceptual framework was designed to depict the assumed relationships. (For complete abstract open document)
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ItemDisturbances in processing inferences in language following right hemisphere brain damage( 1982)It was argued, that contrary to conventional localisation models attributing all linguistic function to the left hemisphere, the right hemisphere played an important part in the processing of paralinguistic information. Studies of disturbances in prosody; understanding of emotional content in verbal messages; processing of visuospatial aspects of language and processing of pictorial information following right hemisphere damage were reviewed. It was suggested that right hemisphere damaged patients appear to have particular difficulty in drawing inferences from verbal messages, implying an inability to integrate verbal information. It was decided to explore the ability of right hemisphere patients to draw simple inferences from material which was deliberately lacking in emotional content and was designed to contrast the ability to process visuospatial information from non-spatial information. A short memory task was created in which recognition of items which were not heard before but which were semantically continuous with the original story would indicate the integration and storing of the information in the story, rather than its actual lexical representation. A pictorial analogue was also designed to explore pictorial processing. A task matching pictorial alternatives to spoken metaphors was also included since it was suggested the right hemisphere patients were unable to do this task. Three experimental groups were explored; right anterior cortical brain damaged patients; right posterior cortical brain damaged patients, and right subcortical (capsular) and sex was also included. The results indicated that contrary to expectation, the right cortical brain damaged group could process inferences in language both spatial and non-spatial. However, it was found that these patients have a particular problem in rejecting recognition items which did not belong to the original set. This difficulty appeared to be exacerbated when the original material was semantically redundent or involved an understanding of spatial relationships. It was speculated that this may reflect a retrieval rather than memorising difficulty. The performance of the cortical patients on pictorial tasks was found to be more severely disturbed than verbal, and this was considered to be possibly due to a failure to resolve the alternative meanings of the pictures. The cortical patients were also found to prefer literal pictorial alternatives for metaphors, more often than controls. This was also speculated to be due to some failure to appreciate the appropriate meaning of the spoken metaphor, or a difficulty in processing the pictorial information correctly to select a picture depicting the appropriate interpretation. The subcortical (capsular) group performed distinctly differently from the cortical group. It was argued that while these patients also had difficulty rejecting items as not belonging to a cognitive set, they also appeared to be performing in a manner originally expected of the cortical group, i.e. there was suspicion that they were not storing information for meaning but for other more superficial characteristics. These patients performed uniformly regardless of the mode of presentation, pictorial or verbal. They also showed some tendency to select literal meanings of metaphors more often than controls.
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ItemThe general aptitude test battery: an Australian empirical study( 1972)The General Aptitude Test Battery developed by the US Department of Labor in the 1940's is probably the most widely used multifactor aptitude test battery in the world. Not only is it a technically well constructed instrument, extensively used in the United States and other countries but its use has been accompanied by a large, ongoing programme of occupational validation studies which has enhanced its value to the psychologist or personnel officer engaged in employee selection or vocational guidance. In this study, conducted in 1971, a slightly modified version of the GATB was administered to two samples drawn from all Australian States. One of the samples consisted of 1355 National Servicemen tested during basic Army training and the other of 1562 students from the top four grades of Australian secondary schools. Performance of the samples is examined and compared with that of similar samples in the United States and Canada. In addition to overall performance the study deals with validity, item analysis, reliability and the general applicability of US norms for Australian purposes.