Melbourne School of Psychological Sciences - Theses
Now showing items 1-12 of 276
Investigating the construct validity of contemporary cognitive assessment
Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV) is the most commonly used instrument for the assessment of cognitive abilities, and in making high-stakes decisions in Australia. The current thesis comprises four studies related to the validity of using WAIS-IV in cognitive assessment. The norms for the WAIS-IV used in Australia are based on the US standardization sample. The Woodcock Johnson III (WJ III) battery has been normed for Australian population under the age of 22. This study investigated the score equivalence of the WAIS-IV and the WJ III cognitive test battery in an Australian university student sample. One hundred and sixty-four participants, of whom 38 undertook both tests, were assigned to tests in a blocked, random order. Scores from all, and from those aged less than 22 years, were analysed. The Full Scale Intelligence Quotient of the WAIS-IV was significantly higher than the WJ III General Intellectual Ability score in every analysis. The effect sizes were medium and large in the independent and repeated measure analyses respectively. We argue for norming of the WAIS-IV, or any test used for high-stakes assessment, for Australian population to ensure fairer decisions. In the second study a five-factor model was found that fitted the WAIS-IV U.S. 15-indicator standardization samples for the nine age-groups between 16 and 69 years (N for each group = 200). A strong metric invariance for three of the five factors and a partial intercept invariance for the remaining two was established. Pairwise comparisons of adjacent age groups supported the inference that cognitive-trait group differences are manifested by group differences in the test scores. The third study sought a common model for a clinical sample of scores (N= 321) and the standardization samples. The clinical sampled differed from the standardization samples in that (a) the heterogeneous clinical sample comprised scores from patients, aged 16 to 91, with disparate neurological diagnosis in contrast to the nine age-group stratified standardization samples, (b) only the 10 core subtests were administered in the clinical sample, and (c) the clinical sample had missing data. We found (a) a difference in response strategy between the clinical and non-clinical sample, but (b) a weak factorial invariance of a five-factor measurement model across the clinical and standardization samples. We argue that the results do not disconfirm the hypothesis that the same five latent abilities found in the analysis of the 15 subtest scores in the standardization samples underlie the scores in the clinical population. In the fourth study six models from prior studies were used to generate Monte Carlo simulation data to assess sampling variation in outcomes when model misspecification is restricted to the alternate models canvassed for WAIS-IV. We found that (a) the fit of most models to samples from the different populations were good, (b) the estimated value of a parameter unrelated to the variables germane to the misspecification is true to the population value, (c) increased sample size slightly improved RMSEA, and had minimal effect on parameter estimates, (d) the average fit measures in estimations with and without warnings were not different, (e) the number of replications had minimal effect on the fit and the estimated parameter values. The results suggest that (a) post hoc modification to improve fit in a single sample is difficult to justify, (b) even in an ill-fitting model the estimates of parameters unrelated to the misspecification may be accurate, and (c) theoretical insight and heuristic reasoning aid the identification of problematic parameters.
Implications of different patterns of non-symbolic and symbolic magnitude representations for children’s mathematical abilities
It has been argued that early math ability rests on two core, putatively innate, number systems: a precise small number system that allows an accurate and rapid apprehension of the numerosity of small sets (i.e., subitizing), and an approximate magnitude representation that allows discrimination between quantities. Moreover, differences in core number systems functioning are claimed to underlie differences in math ability. It is, furthermore, claimed that non-symbolic magnitude representations scaffold symbolic magnitude representations and ipso facto, math abilities. While these claims are frequently made, evidence in support of them is less than convincing. One difficulty in clarifying the relationships between the two magnitude representations, or core number and maths abilities, is the large inter-individual variation in these abilities in young children which may obscure the relationships between them. Most research that has examined this issue has used variable-oriented analytic methods that treat variance as error or noise. It is proposed herein that using a person-centred analytic method (i.e., latent profile modelling) to explicate the variance may allow identification of different ability patterns (latent profiles) that reside within the overall variance distribution and, in turn, provide a more nuanced developmental model of numerical cognition. To this end, three studies were conducted that focus on the significance of different patterns of non-symbolic–symbolic magnitude representations (Studies 1 and 2), and the relationship between these patterns and different patterns of the apprehension of small sets (Study 3). In Study 1(a), 124 five- to seven-year-old children completed non-symbolic and symbolic magnitude judgement tasks, cognitive measures often associated with math ability (visuo-spatial working memory [VSWM], naming Hindu-Arabic numbers and processing speed) as well as transcoding, and a single digit addition (SDA) test. A latent profile analysis (LPA) of the magnitude judgment accuracies and response times revealed four different patterns of non-symbolic–symbolic magnitude ability relationships residing within the overall variance distribution. The cognitive measures were related to the four profiles in different ways; and the profiles predicted differences in SDA and transcoding abilities. In Study 2(b), a partial replication of Study 1, 109 five- to six-year-old children completed the same tasks as Study 1 twice–one year apart. Latent transition analysis, a longitudinal extension of LPA, examined change and stability patterns in the four profiles over time. Similar to Study 1, the findings showed the patterns were differentially associated with cognitive and math abilities. Study 3 examined the relationship between non-symbolic–symbolic magnitude ability patterns and small precise number ability patterns. The findings replicated those of Studies 1 and 2, and also showed an overlap in the two core number abilities. While only VSWM and magnitude ability patterns predicted SDA abilities (over and above small precise number abilities); both magnitude ability and small precise number ability patterns predicted single-digit subtraction abilities over and above the other cognitive factors. In summary, the findings reported herein confirm the existence of different magnitude ability relation patterns which are differentially associated with different cognitive and math abilities. Examining the change/stability pathways in these ability patterns may reveal typical and atypical pathways of math development. It is evident that different magnitude ability relation patterns partially overlap with the small precise number ability patterns. Nonetheless, differences in the patterns in the two core number indices, along with differences in cognitive indices, predict different math abilities (i.e., single-digit addition and subtraction). The overall pattern of findings is discussed in terms of a more nuanced model of numerical cognition, as well as the value of the findings for specifying diagnostic markers of early math difficulties. (a) Chew, C. S., Forte, J. D., & Reeve, R. A. (2016). Cognitive factors affecting children’s nonsymbolic and symbolic magnitude judgment abilities: A latent profile analysis. Journal of Experimental Child Psychology, 152, 173-191. https://doi.org/10.1016/j.jecp.2016.07.001 (b) Chew, C. S., Forte, J. D., & Reeve, R. A. (2019). Implications of change/stability patterns in children’s non-symbolic and symbolic magnitude judgement abilities over one year: A latent transition analysis. Frontiers in Psychology, 10, 441. https://doi.org/10.3389/fpsyg.2019.00441
Towards understanding choice biases
Our choices can often be biased in systematic ways. In this thesis, we study the cognitive mechanisms driving two prominent choice biases: the endowment effect and the descriptive norm effect. The endowment effect, a tendency to assign higher value to something you own, is typically explained based on loss aversion. A finding that the endowment effect reverses for choices between undesirable options has been taken as evidence against loss aversion. We find that these reversals are driven by people’s expectations and only seem to occur when comparisons between the options are limited. We outline a model of loss aversion that can qualitatively and quantitatively account for these results. The descriptive norm effect, a bias towards popular options, is typically explained based on the fact that descriptive norms offer useful information as to which option is best. We show that descriptive norm effects occur even when the norm is entirely arbitrary and thus offers no useful information. Another prominent explanation of the descriptive norm effect, self categorization theory, can explain the impact of these arbitrary norms. However, this theory predicts that people will avoid conforming to descriptive norms from an outgroup. We find this not to be the case, with participants’ preferences shifting towards outgroup descriptive norms. We discuss how mechanisms from the broader choice bias literature could in principle explain our findings.
Exploring the structure of moral values
The field of moral psychology is home to a range of theories providing competing descriptions of the structure of morality. However, two major obstacles inhibit progress in refining, refuting or integrating these various descriptions. First, researchers do not have an adequate range of diverse, systematically validated materials for designing studies that provide insights into the structure of morality. Second, the field has yet to adopt methodological approaches that can provide clear assessments of the relative merits of different descriptions of morality. The goal of this thesis is to address both obstacles across a series of nine studies that report the development, validation, and demonstration of a set of new methodological tools for use in moral psychology research. In a first set of five studies we fill a major gap in the methodological literature, describing the development and validation of the Socio-Moral Image Database (SMID), a normed database of 2,941 morally-laden photographic images for use in experimental research. In a second set of studies, we then present the development and validation of a novel approach to studying morality via natural language by applying topic modelling to large corpora of Wikipedia articles, generating models that can be used to provide detailed, automated descriptions of the moral content of new texts in multiple languages. In a final study, we demonstrate the use of Representational Similarity Analysis, applied to similarity judgments of morally-laden SMID images, to provide a direct comparison of two competing descriptions of the structure of morality: Moral Foundations Theory (MFT) and the Model of Moral Motives (with results tentatively favouring the former theory). Across these nine studies, this thesis presents a collection of methodological tools and approaches that can be used for novel studies of the cognitive, affective and neural processes underlying moral cognition, and of morality-related societal, cultural and historical phenomena.
Social modulation of affordance perception
Joint actions, such as lifting and moving objects with a partner, are fundamental to human co-operation. In the present thesis, I sought to build upon a growing body of literature that investigates the role of spontaneous cognitive processes (i.e., processes that occur even when there is no joint action goal) in joint action. Specifically, I aimed to test whether the presence of a co-actor modulates our perception of affordances, or the set of actions that an object allows an observer. To this end, I adapted an object-based two-choice paradigm, in which participants make left/right responses to unilaterally graspable objects, for joint responding. Typically, response times (RTs) in such tasks are faster when the task-irrelevant handle orientation of the viewed objects is aligned with the responding hand. This object-based compatibility effect (CE) is often taken as evidence that viewed objects elicit motor activation consistent with their afforded grasp, even when there is no grasp intention. In Study 1, participants (N = 48) completed individual and joint versions of an object-based two-choice task. However, I failed to replicate the object-based CE in the standard (i.e. individual) two-choice task, instead finding a numerical negative CE (NCE). In Study 2 (Ns = 36), I conducted two experiments to test whether Study 1’s failure to replicate the CE could be due to pixel asymmetry (the proportion of pixels either side of fixation) modulating the object-based CE. I show that between-object (due to object shape) and within-object (due to object placement) variation in pixel asymmetry can attenuate, or even reverse, CEs. In light of finding that stimulus spatial properties modulated the object-based CE, I sought to determine whether the effect was indicative of affordance perception at all. In Study 3, I meta-analyzed the object-based CE to test whether it is better explained by spatial coding accounts, which propose that the effect is merely an example of a broader class of spatial CEs elicited by the unilaterally protruding handles of objects. Analysis of 88 independent effects (from 2359 participants) revealed a small, yet significant CE, as well as evidence of publication bias. Further, moderator analysis offered little support for affordance-based explanations of the object-based CE. Rather, results supported a spatial coding account. To test whether viewed objects can facilitate compatible responses at all, I asked participants in Study 4 to complete a novel Bimanual Affordance Task (BMAT), which sidesteps spatial confounds by featuring symmetrical stimuli. I observed the expected affordance x response compatibility effect, such that unimanual responses were faster to unimanually graspable objects, while bimanual responses were faster to bimanually graspable objects. In Studies 5-6, pairs of participants shared the BMAT: Overall, I found that co-action modulates affordance perception, such that it facilitates responses to bimanual (joint), but not unimanual (individual), grasp-affording objects. In all, results from this thesis imply that (1) traditional object-based two-choice tasks are unsuitable for affordance research due to spatial confounds, and (2) that we spontaneously perceive affordances for the dyad (i.e. joint affordances) when a co-actor is present.
Culture, Self-Narratives and Autobiographical Memory: Using a Semiotic Narrative Approach to Investigate Cross-cultural Differences
Various methods have been utilized to study culture and self. Despite advances in research on narratives and culture in understanding the self, to date, there is a lack of empirical studies investigating the cross-cultural differences in self-narrative structure. A self-narrative approach is important to unpack how the self differs cross-culturally because ‘What’ and ‘How’ people narrate about themselves is informed by their cultures. This thesis demonstrates the use of a semiotic narrative structure proposed by Greimas, particularly the Actantial Model, as a methodologically principled way of understanding how individuals construct culturally-informed selves in their self-narratives. To address the overarching aim of investigating cross-cultural differences using a semiotic narrative approach, three questions are raised concerning ‘What’ contents and ‘How’ people narrate about themselves as well as how self-narration relates to autobiographical memory in constructing a self-narrative in different cultures. Three studies are conducted. Study 1 utilized interviews to explore and test the coding system as well as the viability of Greimas’s framework as a systematic approach in analyzing self-narratives in cultural comparative research. Qualitative differences in self-narrative contents consistent with past research are replicated with this method. Key episodes in autobiographical memory were found in the contents of the self-narrative structure, showing that the experiences stored in autobiographical memory are used to construct self-narratives. Study 1 results are used to develop an online survey for self-narrative research, which was piloted and validated in Study 2. Through a mixed-method design, Study 2 found variations in self-narrative structure and self-narrating style between European-Australians and Singaporean/Malaysian Chinese. Contents of key events and self-narrative structure were associated, with self-agency as a major theme of what individuals recall. Study 3 employed an online survey developed from Study 2, with a sample of European-Australians (n = 60) and Singaporean Chinese (n = 60). Firstly, qualitative and quantitative evidence indicated cross-cultural differences in 'What’ people share in the contents of their self-narratives. European-Australians present with more individual self-focused contents compared to the Singaporean Chinese, who had more other-focused contents in their self-narratives. Secondly, how people share their self-narratives, which is their self-narrating style, also differed cross-culturally. European-Australians use an elaborative style consistent with previous research, and prioritize the individual self in the foreground, which is termed a decontextualized self-narrating style. In contrast, the Singaporean Chinese showed evidence of repetitive style consistent with previous research, and present a self that is embedded in social context, which is termed a contextualized self-narrating style. Thirdly, how self-narration and autobiographical memory are related was demonstrated through the key events of individuals’ lives which were again found in the self-narrative structure. The memories that engage self-agency are recalled most in key events and used in self-narrative construction. Lastly, important to both cultural groups is the role of religion in individual lives, which can now be investigated within the self-narrative structure as it influences identity and self-processes. Together, these findings reveal the importance and implications of a semiotic narrative approach in understanding not only cross-cultural differences, but also how culture and self co-construct.
Examining the cognitive consequences of white matter tract damage in mild traumatic brain injury
Mild traumatic brain injury (mTBI) has been the subject of an enormous body of research spanning back to the 10th century. Despite the sheer volume of studies in this area, mTBI is still poorly understood, particularly in terms of cognitive consequences and injury to white matter tracts in the brain. The research project central to this thesis employed innovative and novel cognitive and diffusion weighted-imaging (DWI) techniques. The overarching aim of this project was to provide a more sensitive and specific examination of cognition and white matter tract damage following mTBI, than currently exists in the literature. The thesis also aimed to examine the relationship between cognition and white matter tract damage following mTBI. A Systematic Review and Meta-Analysis (Chapter 5) was conducted to examine the current understanding of this relationship; the findings revealed that this area has received relatively little attention within the broader body of mTBI research. The study central to this thesis included a sample of patients with mTBI and a matched trauma control (TC) group who were recruited from the largest tertiary referral trauma hospital in Australasia, The Alfred hospital (Melbourne, Victoria, Australia). Approximately 6-10 weeks post-injury, participants returned to the hospital to take part in a comprehensive examination involving a neuropsychological assessment, select questionnaire measures, and a magnetic resonance imaging (MRI) scan that included DWI sequences. Study One comprised findings of the neuropsychological assessment. The assessment was comprehensive in scope and included conventional “paper-and-pen” tests as well as two computer-based tasks designed to place greater load on cognitive systems. The design of the neuropsychological assessment addressed key limitations of existing research, such as the use of brief cognitive screens or use of only a small number of cognitive measures. The findings of Study One revealed that the mTBI and TC groups performed similarly on conventional neuropsychological assessment tools; however, novel computerised cognitive measures revealed impairments specifically in the mTBI group. Study Two addressed key limitations of DWI-based research in mTBI, namely the predominant use of diffusion-tensor imaging (DTI). The data acquisition, processing, and tractography-based methods were designed to provide a more thorough and specific examination of white matter tract microstructure following mTBI. By use of an additional DWI-based modelling technique, neurite orientation dispersion and density imaging (NODDI), Study Two revealed more specific information about white matter tract microstructural changes relative to existing DTI-based research. Within white matter tracts commonly implicated in mTBI, the combined use of DTI and NODDI revealed alterations to quantitative DWI metrics suggestive of axonal injury and degeneration. The third study included in this thesis built upon the findings of the Systematic Review and Meta-Analysis and examined the relationship between white matter tract microstructure and cognition in both the mTBI and TC groups. Study Three revealed distinct associations between cognitive and DWI quantitative measures within the two groups. For the TC group, higher cognitive performance was associated with DWI metrics suggestive of greater diffusion of water molecules along fibre bundles, as well as greater density and coherence of white matter tracts. These associations were consistent with expectations based on existing research within healthy adult populations. In contrast, within the mTBI group, no associations were observed with measures of speed of information processing or attention. While there were a small number of significant associations in the mTBI group between DWI metrics and performance on measures of memory and executive function, the relationships were in the opposite direction to those observed in the TC group. That is, higher cognitive performance was associated with reduced diffusion of water molecules along fibre bundles, and both lower density and coherence of fibres within white matter tracts. These associations were consistent across white matter tracts examined and cognitive domains. Collectively, the studies included in this thesis make a significant contribution to the mTBI research literature. While no marked impairment was found on conventional neuropsychological tests, changes to white matter tract microstructure were apparent 6-10 weeks following mTBI on measures of cognition that are sensitive to mTBI-related neuropathological change. Use of NODDI in conjunction with DTI revealed more specific information about underlying white matter microstructural changes following mTBI, relative to existing research. Furthermore, the discrepancy in findings between the mTBI and TC groups indicates that there is an abnormal relationship between white matter microstructure and cognitive function 6-10 weeks following mTBI.
Drumming up harmony: How rhythmic synchronisation fosters pro-sociality
Rhythm is a natural and ubiquitous phenomenon in human culture, which has potential utility in scientific research and clinical practice beyond its customary cultural and aesthetic applications. For example, a growing body of research suggests that rhythmic synchronisation promotes social cohesion and pro-social behaviour ("The Sync Effect;" e.g. Hove & Risen, 2009; Kirschner & Tomasello, 2010; Reddish, Fisher & Bulbulia, 2013; Rennung & Goeritz, 2016). However, some aspects of rhythm remain poorly understood, which limits research and hampers the development of practical interventions. The overarching goal of this thesis is to elucidate the mechanism(s) by which rhythmic synchronisation might produce pro-sociality, and thereby advance the development of interventions for use in clinical, community and educational settings to reduce social isolation and to promote social cohesion and pro-sociality. To address this aim, it was necessary to elucidate the factors that influence rhythm difficulty. A literature review revealed that predictions of rhythm difficulty based on algorithmic models are unreliable, supported by very limited empirical research, using very few rhythms and a small, culturally constrained participant population. These limitations were addressed across two studies. Study 1 compared three prominent algorithmic models of rhythm complexity across every possible rhythm of 8, 12, and 16 events. Results revealed that no model was clearly superior, none of the algorithms accounted for rhythm length or for different types of syncopation, and large discrepancies were apparent between the measures on a number of rhythms. Study 1 concluded that these inconsistencies limit the utility of existing algorithmic models in predicting the difficulty of individual rhythms. Study 2 gathered difficulty ratings and performance data for a large sample of rhythms, from a large and culturally diverse participant sample in order to determine which characteristics of participants and rhythms combine to predict the difficulty of human rhythm performance. Results showed that particular types of training produce rhythm skill and familiarity, which predict performance better than simply ‘years of musical training’ or algorithmically-determined metrical complexity. Redundancy and long gaps within rhythms also influenced difficulty, but high levels of rhythm skill or familiarity tended to overcome these effects. Study 3 involved a systematic review of the rhythmic synchronisation literature, which identified a range of methodological limitations. To address these concerns, a conceptual framework was proposed, to clarify terminology and to differentiate between different types of coordinated behaviours. Existing research was examined in terms of the conceptual framework to clarify the evidence in support of The Sync Effect, to explain contradictions in the literature, and to highlight important methodological considerations necessary to support progress in the field. Study 4 strategically manipulated difficulty and other musical and social conditions in a dyadic drumming paradigm designed to test three mechanisms by which rhythmic synchronisation is thought to generate pro-sociality. Results suggest that reward network activation and multi-level social-cognitive processes combine to yield powerful pro-social effects when rhythms are complementary and/or optimally challenging. This has implications for the types of coordinated interpersonal behaviours that may be of use in clinical and community interventions to foster social cohesion and pro-social behaviour.
Global meaning and its implications for emotional adjustment following a cancer diagnosis
This thesis examined the course of global meaning following diagnosis with cancer and explored its role in emotional adjustment using Janoff-Bulman’s (1992) assumptive world model. The study aimed to find evidence that there is a normative tendency to hold unrealistically positive global meanings which are contradicted by an adverse life event and the resultant emotional distress is resolved either through reinterpreting the event in a more positive light (assimilation) or revising meanings to be more realistic (accommodation). Assimilation is thought to be associated with favorable emotional functioning while accommodation has been linked to worse emotional outcomes (Janoff-Bulman, 1992). Using a longitudinal design, 86 adults with a hematologic cancer were assessed three times: following diagnosis; after primary treatment and: one year postdiagnosis (N=63). Data collected included six indices of emotional adjustment (depression, anxiety, traumatic stress, joviality, self-assurance and serenity); a measure of global meaning, the World Assumptions Scale (Janoff-Bulman, 1992) and, demographic and medical information. Three sets of analyses were conducted. The first set of analyses examined the course of emotional outcomes and global meaning over the year-long study period. Anxiety was the only emotional outcome showing overall change (decrease) while randomness was the only meaning displaying change (increase) over time. The study samples’ world assumptions were also compared with those of general community groups and motor vehicle accident survivors. At study entry, the sample displayed more positive bias in self and benevolence meanings than the other groups. By study exit, they showed less positive bias in contingency assumptions than the comparison groups, a pattern consistent with accommodation. The second set of analyses assessed whether global meaning predicted emotional outcomes when effects of demographic and medical factors had been accounted for. Meaning was implicated in all six emotional outcomes, with variability in their predictive power relative to the outcome measure and time of assessment. Self-worth and luck assumptions were the strongest predictors with justice and randomness also showing some predictive power. The final set of analyses used longitudinal data to focus on the association between global meaning and trajectories of emotional adjustment over time. The findings indicated that self-worth was associated with better outcomes for anxiety and TSS; luck was associated with depression while people benevolence was associated with anxiety. The directions of associations for all but people benevolence were consistent with the expectation that more positive bias in meanings is related to more favorable outcomes. The finding of a significant increase in randomness provides some support for the hypothesis that positively biased global meanings are challenged by the cancer experience and accommodate to become more realistic, although randomness did not predict worse emotional outcomes over time. Self-worth and luck, which were relatively high compared to other groups and stayed stable over the study period, were most strongly implicated in adjustment. The results also provide some impetus for a reconceptualization of the meaning in adversity models to take into account state-like variability in global meaning constructs.
The mental health of Australian lawyers: a self-determination theory based model
Media and public opinion have portrayed Australian lawyers as a group rife with psychopathology and behavioural dysfunction. Despite the ubiquity of these views, empirical research on the mental health of lawyers, particularly from a well-being perspective, has been limited. This research examined both psychological distress and well-being aspects of mental health in a diverse sample of 762 Australian lawyers. In study one, the mental health of Australian lawyers was compared with population norms. The relationships between various types of psychological distress with hedonic and eudaimonic well-being was also examined. In study two, Self-Determination Theory was adopted as a critical approach to explore factors influencing lawyer mental health. Lawyers’ passion for work and the extent to which they perceived their managers to be autonomy supportive were examined in relation to well-being at work and mental health. Finally, the extent to which these relationships were mediated by the satisfaction and frustration of the basic psychological needs for autonomy, competence and relatedness was tested. As predicted, higher levels of well-being were predictive of lower levels of all types of psychological distress. Also as predicted, higher levels of harmonious passion for work was associated with reduced psychological distress and greater well-being both at work and in general. Higher levels of obsessive passion for work, was predictive of higher workplace well-being and psychological distress but was unrelated to overall well-being. Also as predicted, the extent to which lawyers experienced their managers as autonomy supportive was predictive of higher levels of well-being and lower levels of psychological distress. Mediation analysis suggested that well-being in the work domain is critical for the overall mental health of lawyers and the mechanism by which harmonious passion and manager autonomy support influence well-being at work is by satisfying basic psychological needs. These findings add important depth to previous investigations of lawyer well-being by demonstrating the important contribution of previously unexplored individual difference and environmental factors. Strategies that encourage a balanced and positive engagement with work, as well as environments that promote autonomy are most likely to reduce psychological distress and increase well-being among lawyers of all types. Whilst legal professions worldwide rally to tackle a mental health crisis, this research provides evidence for interventions that are likely to be effective at combating cultural issues and to increase flourishing.
The role of attention in subitizing
This thesis aimed to address a long-standing question: “Why are small numbers of items enumerated differently from large numbers of items?” (Trick & Pylyshyn, 1993, p. 331). Specifically, this thesis examined whether the processing of small sets requires attention processes and, if so, how attention plays a role in subitizing. Answers to this question are central to debates about the nature of contemporary models of numerical cognition. In this thesis, attention was manipulated in an enumeration task using the Posner Cueing paradigm. The physical properties of to-be-enumerated objects in the experiments were well-controlled. Different display times of objects were used in the experiments. An internal mini meta-analysis was run to synthesize the attention effects in these experiments. A meta-analysis was also conducted to evaluate the observed attention effects in previous studies. Moreover, to investigate how attention plays a role in the subitizing range, experiments was conducted to compare the attention effect between an enumeration task and a control task. Findings from the experiments reported in this thesis suggested a robust attention effect in the subitizing range: there was no dichotomy in attention between subitizing and counting. These findings imply that subitizing processing requires attention. The meta- analysis evaluating previous studies also suggested a robust attention effect in the subitizing range. Moreover, the findings reported in this thesis suggested that attention does not specifically affect numerical processing. Instead, attention played an important role in general cognitive processes in the subitizing range. A tentative model was proposed to explain the mechanisms underlying visual enumeration, especially in the subitizing range. In summary, these findings suggest that enumeration in the subitizing range requires attention. Specifically, attention is required for general processes in the subitizing range.
Investigating the relationships between regulatory focus and needs satisfaction at work
Work is becoming more mobile, remote, and fragmented, which makes strategies to enhance motivation increasingly important in organizations. Research on work motivation has shown that the ability of people to adjust behavior and the extent to which their choices and activities are self-determined are among the most relevant factors that shape motivation at work. In this respect, regulatory focus theory and theories of psychological needs have contributed much to the study of work motivation. However, little research has investigated potential connections between these two powerhouses of motivation. To address this issue, this thesis is the first to investigate in depth associations between regulatory focus and psychological needs satisfaction at work. Moreover, it investigates whether regulatory focus may operate in part through psychological needs satisfaction to influence work outcomes like job satisfaction, work engagement, burnout, and turnover intentions. Based on dual literature reviews of the regulatory focus and needs satisfaction literatures, I propose a theoretical framework that links regulatory focus with satisfaction of needs that involve security and growth at work, and use this framework to assess the impact of these processes on work outcomes. Four empirical studies with data from more than 1,000 employees test this framework. Results suggest that work-specific promotion focus and prevention focus are associated with satisfaction of different work-related needs involving growth and security. Further, the relationship between promotion focus and work growth needs is partly explained by job crafting to increase challenges, while the relationship between prevention focus and work security needs is partly explained by job crafting to decrease hindrances. The thesis concludes with a discussion of how these findings can inform interventions to improve work motivation, and recommends future research to determine causality and test the framework using alternative methodologies.