https://bura.brunel.ac.uk/handle/2438/256 2026-10-23T18:08:05Z 2026-10-23T18:08:05Z Dalton, Stefan Daniel Paul https://bura.brunel.ac.uk/handle/2438/33997 2026-10-15T02:01:21Z 2026-01-01T00:00:00Z

Title: Implicit core belief adaptation integrated cognitive behavioural therapy Authors: Dalton, Stefan Daniel Paul Abstract: Emotions have been at the forefront of philosophers’ and theoreticians’ curiosities for millennia. A great deal of influential research has described how emotions are defined, generated, and regulated, and many theoretical models have further described the processes underlying the maintenance of psychiatric disorders. Although implicit mechanisms are frequently documented, cognitive behavioural therapy (CBT) practices largely rely on explicit techniques such as cognitive reappraisal. Given the large body of evidence suggesting emotion generation, emotion regulation, and emotional disorders largely operate via implicit mechanisms, the present PhD thesis investigated implicit emotion processing and potential techniques for utilising implicit emotion regulation strategies within brief CBT interventions. This thesis adopted several methodological approaches, including meta-analyses, behavioural studies, and intervention studies. Several novel findings were reported. First, behavioural and fMRI meta-analyses reported maladaptive implicit emotion regulation in mood and anxiety disorder samples compared to healthy controls, further highlighting dysfunctional neural activation in patients within the medial prefrontal cortex. Second, implicit cognitive reappraisal was reported to be effective across symptom measures related to the cognitive model of emotional disorders, particularly at reducing maladaptive core beliefs. Third, the development of a standardised digital single-session cognitive behavioural therapy intervention for a presenting emotional complaint was effective on symptom measures, including GAD-7 scores, negative automatic thoughts, avoidance, and maladaptive core beliefs. Finally, the newly introduced implicit facial stimuli exposure integrated single-session CBT was reported to be increasingly effective on equivalent symptom measures. The findings are discussed within the context of influential theories and models of emotion generation, emotion regulation, emotional disorders, and goal-directed behaviours. From this, the emerging theory of implicit core belief adaptation is presented, which is hypothesised to be the implicit activation of adaptive core beliefs surrounding safety, acceptance, and connection via implicit exposure to facial stimuli. In conclusion, harnessing evolutionary mechanisms in response to facial stimuli may have important implications for adaptive cognitive, emotional, and behavioural responses, further highlighting their importance in both research, and potentially, psychiatric practice. Description: This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London

2026-01-01T00:00:00Z Pandya, Snehal P. https://bura.brunel.ac.uk/handle/2438/33206 2026-04-26T18:50:00Z 2025-01-01T00:00:00Z

Title: Effect of polygenic risk scores for Alzheimer's disease on brain structure, cerebrospinal fluid, and cognition Authors: Pandya, Snehal P. Abstract: Background: Apolipoprotein E (APOE) is the most studied gene in relation to, and has the strongest genetic association with, sporadic Alzheimer’s disease (AD). The APOE epsilon 4 (ɛ4) risk variant is found in approximately 14% of the general population and in approximately 37% of the AD population, globally. This indicates that the presence of ɛ4 is not required for the development of sporadic AD. In fact, sporadic AD is considered a polygenic disease with thousands of causative variants. Therefore, there is a need to investigate other genes and associated variants, and the concurrent effect of these on sporadic AD. Polygenic risk scores (PRSs) are ideal for this purpose as they consider multiple genetic variants/single nucleotide polymorphisms (SNPs) that have genome-wide significance, simultaneously. However, PRSs are difficult to calculate since numerous factors must be taken into consideration, and there is no optimal procedure. Nonetheless, PRSs can improve understanding of genotype-to-phenotype associations and risk predictions. Aim: The aim of the current research is to investigate whether PRSs for AD can predict cross-sectional regional grey matter volume (Experiment One), cross-sectional cerebrospinal fluid (CSF) biomarkers (Experiment Two Part A), cross-sectional cognitive markers (Experiment Two Part B), longitudinal CSF biomarkers (Experiment Three Part A), and/or longitudinal cognition (Experiment Three Part B) across the continuum of sporadic AD. Methodology: Participants from the Alzheimer's Disease Neuroimaging Initiative (n = 738; mean age in years: 73.94 ± 7.58) were analysed using various binomial hierarchical logistic regression models, and multiple hierarchical linear regression models, that controlled for numerous demographic and clinical variables. Participants were stratified by several variables to assess risk of AD in different groups. Three PRSs were constructed: PRSwithAPOE, PRSwithoutAPOE, and APOEonlyPRS. SNPs relating to APOE were from the entire APOE region, and three statistical thresholds were calculated for each of the three PRSs. Results: Overall, PRSwithAPOE and APOEonlyPRS were associated consistently with outcome measures. Generally, PRSwithAPOE and APOEonlyPRS were: associated negatively with bilateral hippocampus (right (R) > left (L)), bilateral amygdala (R > L), bilateral entorhinal area, and R middle occipital gyrus; associated positively with CSF amyloid-beta 42 (Aβ42) more than they were with CSF phosphorylated-tau181 (p-tau181), cross-sectionally; associated negatively with memory and visuospatial cognition, cross-sectionally; associated with CSF p-tau181 more than they were with CSF Aβ42, longitudinally; associated positively with longitudinal cognitive decline. Discussion: The results highlight that stratification by amyloid positivity improves risk prediction over stratification by clinical diagnosis. The findings also concur to previous literature indicating that CSF amyloid decreases early on in AD after which it reaches a plateau, whereas changes in tau continue throughout the disease. The current research presents a novel, systematic, and thorough approach to evaluate risk of sporadic AD, including: a multi-modal approach that assesses outcome measures that are used to diagnose individuals with AD clinically (i.e., brain structure, CSF biomarkers, and symptomology); the use of both cross-sectional and longitudinal study designs; a multi-stratification approach whereby participants are divided in several ways to assess risk in different groups – for some groups, findings have been reported for the first time (to knowledge). Conclusion: This work highlights the added value of non-ɛ4-APOE SNPs and non-APOE SNPs (i.e., both PRSwithAPOE and APOEonlyPRS) in detecting associations with AD-specific cross-sectional and longitudinal outcome measures. In parallel with existing literature, an ideal threshold has not been determined in the current research. However, it may be that certain thresholds identify associations better according to the outcome measure at hand. Additionally, the current research demonstrates the clinical relevance of PRSs for AD and that these may support diagnosis and prognosis of AD. It is recommended that future investigations assess PRSwithAPOE and APOEonlyPRS with longitudinal CSF biomarkers, in independent samples, and in ethnically diverse populations. Description: This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London

2025-01-01T00:00:00Z Bennetts, RJ Butcher, N Lander, K https://bura.brunel.ac.uk/handle/2438/32717 2026-01-26T03:01:04Z 2025-10-30T00:00:00Z

Title: Consistent Eye Movement Patterns in Static and Dynamic Face Recognition: A Hidden Markov Model Study Authors: Bennetts, RJ; Butcher, N; Lander, K Abstract: Background/Objectives: Eye movements provide important insights into face processing. Hidden Markov models of eye movements (EMHMMs) are a relatively new approach that identifies common patterns across observers, moving beyond region-of-interest analyses. Prior EMHMM studies with static faces have typically revealed two strategies: a central “holistic” style and a feature-based “analytical” style. However, it is unknown whether such patterns extend to dynamic faces, which more closely reflect real-world viewing. This study is the first to apply EMHMMs to dynamic face recognition. Methods: Participants completed a face learning task in which half of the identities were presented as static images and half as dynamic videos. Eye movements were analysed using EMHMMs during both learning and recognition phases. Results: Two consistent patterns emerged across conditions: Central-focused and Eye-focused. A small subgroup displayed a third, central-plus-right-eye pattern when learning static faces. Eye movement patterns were largely stable across static and dynamic conditions, with only 16–27% of participants switching between them. Patterns were generally unrelated to recognition accuracy; however, participants adopting Eye-focused patterns during static learning performed better on static recognition. Conclusions: EMHMM-identified patterns generalise from static to dynamic faces, indicating strong stability in face-viewing behaviour across stimulus types. This finding contrasts with previous region-of-interest analyses suggesting greater differences between static and dynamic faces. By extending EMHMMs to dynamic faces, this study underscores the value of diverse analytical approaches for capturing eye movement behaviour and advancing understanding in face processing. Description: Data Availability Statement: The individual participant data on which study conclusions are based and a list of all the stimulus materials have been made publicly available on the Open Science Framework (see https://osf.io/xz2hr/).

2025-10-30T00:00:00Z King, Tavis Ryan https://bura.brunel.ac.uk/handle/2438/32397 2025-11-25T03:01:08Z 2025-01-01T00:00:00Z

Title: Taking pride from cultures of shame: The influence of cultural values on the development of internalised attitudes towards same-sex attraction in gay men across cultures Authors: King, Tavis Ryan Abstract: Theoretically, internalised homonegativity (IH-) has been studied by mainstream and lesbian, gay, bisexual, trans and queer (LGBTQ) psychology as an ill-defined individual difference investigated over several paradigms. Historically, psychology’s heterosexist bias has focussed on IH- as a pathologising construct for gay men, without considering how homopositive attitudes could be internalised. Moreover, cross-cultural research investigating gay men’s IH- is scant, and these few studies have not controlled for cultural values. Therefore, this thesis aims to address psychology’s heterosexism by introducing internalised homopositivity (IH+) alongside IH-, within a psycho-socio-cognitive theory of internalised attitudes towards samesex attraction (IASSA). Over three studies with multinational samples, crosssectional designs utilising hierarchical linear regressions (HLR) investigated the relationships between cultural values systems, parental acceptance-rejection, attachment styles and IASSA. 2,276 men sexually attracted to men were volunteer sampled via social media from Brazil, Ireland, Mexico, the United Kingdom and the United States. Each study’s participants completed questionnaire batteries. Study 1 found that conservatism was positively associated with IH- while egalitarianism was negatively associated. Study 2 revealed maternal acceptance was positively associated with IH-, while maternal rejection and paternal acceptance/rejection were not. Study 3 initially found English-speaking cross-cultural validity via exploratory factor analysis for IH+. Subsequent HLR analyses then evidenced high paternal religiosity moderated a negative association between avoidant attachment and IH+; avoidant attachment to mothers was negatively associated with IH+; and cultural masculinity was negatively associated with IH- for both parents across anxious/avoidant attachments. These unexpected results warrant further investigation, particularly the positive association between maternal acceptance and IH- and the negative association between cultural masculinity and IH-. Additionally, the IASSAQ supports future research with a greater unified and less pathologising psycho-social-cognitive IASSA model. Moreover, cross-cultural psychology can be reconciled with LGBTQ psychology. When applied, the IASSA model could help psychological practitioners support ashamed gay men to discover pride. Description: This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London

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