Background: Healthy cognitive ageing entails a number of neurobiological processes which may contribute to optimal functioning and quality of life in ageing. While the full extent of the underlying mechanisms of healthy ageing are yet to be described, there is an important interplay between brain structure, function, and genetic makeup that determines ageing trajectories. Notably, the Apolipoprotein E (APOE) gene has been established in the Alzheimer’s disease (AD) literature to impact brain structure and function, and may also show congruent effects in healthy older adults, although findings in this population are much less consistent. Structural Magnetic Resonance Imaging (MRI), Diffusion Tensor Imaging (DTI), and neuropsychological measures present as useful, non-invasive tools to investigate the impact of APOE allele status on grey matter structure, white matter integrity, and cognitive functioning, respectively. Few studies have used these measures together to describe healthy ageing, and findings are mixed (e.g., no differences seen, different suggested regions of difference, etc.). The current study aims to describe the impact of APOE genotype on brain structure and function in healthy older adults using multimodal methods. Method: Data were obtained from the Alzheimer’s Disease Initiative phase 3 (ADNI3) database. Baseline MRI, DTI and cognitive composite scores for memory (ADNI-Mem) and EF (ADNI-EF) were acquired from 116 healthy controls. Participants were grouped according to APOE allele presence (APOE-ε2+ N= 17, APOE-ε3ε3 N= 64, APOE-ε4+ N=35). Voxel-based morphometry (VBM) and tract based spatial statistics (TBSS) were used to compare grey matter volume (GMV) and white matter integrity respectively between APOE-ε2+ and APOE-ε3ε3 controls, and again between APOE-ε4+ and APOE-ε3ε3 controls. Multivariate analysis of covariance (MANCOVA) was used to examine the effects of APOE polymorphism on memory and EF across all APOE groups with covariates of age, sex, and education, and cognitive scores were correlated (Pearson r) with imaging metrics within groups. Results: No significant differences were seen across groups or within-groups in MRI metrics or cognitive performance (p>0.05, corrected for multiple comparisons). Non-significant trend-level results suggested 1) Increased fractional anisotropy (FA) and GMV was present in APOE-ε2+ compared to APOE-ε3ε3. 2) Increased mean diffusivity (MD) and decreased GMV was present in APOE-ε4+ compared to APOE-ε3ε3 (p<0.2, corrected for multiple comparisons). Non-significant moderate effect sizes were seen for a positive trend between GMV and EF (r= 0.36, p= 0.18) in APOE-ε2+ and a negative trend between MD and EF in APOE-ε4+ (r= -0.33, p= 0.05). Conclusions: APOE polymorphisms do not appear to impact brain structure and function differently in healthy ageing. Trend-level findings align with reports from previous research, although results remain mixed. Overall, this study suggests neurostructural and functional differences across APOE genotype are not present in cognitively healthy older adults, and future studies should aim to clarify APOE mechanisms in healthy ageing with the addition of other variables (e.g., imaging, cognitive, & lifestyle factors), longitudinal design, and in a larger sample. / Graduate / 2022-08-17

The dual nature of emotions as both bodily and cognitive phenomena has posed quite a conundrum for the cognitive sciences, as it does not square well with the long-held conviction that bodily phenomena are not cognitive and that cognitive phenomena do not take place in the body. This stark divide between the bodily and the cognitive has been called into question by so-called situated approaches to cognition that have taken over cognitive science in the last three decades. The framework of situated cognition claims to present a viable alternative to the classical cognitivist position in cognitive science, which regards cognitive processes as disembodied computations over symbolic representations. Instead, proponents of situated cognition aim at showing how cognitive processes crucially depend on an agent’s active engagements with the environment through her body, whereby bodily processes and interactions with the environment become parts of the cognitive process itself, thus lifting the barrier between body and cognition. This Ph.D.-Thesis explores how these recent developments in cognitive science may be applied to emotion theories, so that here too bodily and cognitive aspects of the phenomenon of emotion can be united. In this endeavor a particular focus will be laid on emotions’ intentionality, to explore how an embodied agent’s interactions with the environment impact how they are directed at the world and what emotions are about. After a cursory overview of the history of emotion theories and a brief introduction to situated cognition in section one, the articles in section two provide the necessary terminological and conceptual clarifications and render initial attempts to look into what it means for affective phenomena such as emotions to be situated. Section three draws the focus to the intentionality of emotions and demonstrates how a situated perspective provides a more adequate construal of emotions’ intentionality than the classical cognitivist conceptions. Finally, in section 4, the utility of situated affectivity is exemplified by showing how the embodiment and embeddedness of affective phenomena provides a deeper understanding of the structure of experiences in affective disorders such as depression.

There is a debate among researchers and clinicians as to whether the judicious use of safety behaviours (SBs) during exposure therapy is helpful or detrimental. Central to this debate is the premise that SBs may interfere with one’s ability to gather disconfirmatory evidence. However, no study to date has assessed: 1) how SB use may interact with cognitive mechanisms at play during an exposure-like task, or 2) whether it is SBs themselves, or rather, beliefs about SBs that are most important. The two studies outlined in this dissertation sought to investigate the cognitive, emotional, behavioural, and psychophysiological underpinnings and consequences of exposure with SBs. In Study 1, speech anxious participants (N = 111) were randomly assigned to deliver an evaluated speech with or without SBs. Self-reported anxiety ratings and psychophysiological arousal measures were recorded at baseline, in anticipation of the speech, and following the speech. Measures of working memory capacity, ability to gather disconfirmatory evidence, and speech task acceptability were administered. Results demonstrated no differences between conditions on most outcomes. However, condition did influence willingness to deliver future speeches, such that participants in the SB condition were less willing than those in the NoSB condition to deliver a future speech without SBs. In Study 2, speech anxious participants (N = 144) were given divergent information on the helpfulness of SBs. Participants were randomly assigned to one of three conditions and were told either that SBs are: helpful (decrease anxiety), unhelpful (counterproductive and increase anxiety), or were provided with no information on the anxiolytic effects of SBs (control condition). Self-reported anxiety ratings were recorded at baseline, in anticipation of the speech, and following the speech. Similar to Study 1, measures of working memory capacity, ability to gather disconfirmatory evidence, and speech task acceptability were administered. Results demonstrated that participants in the helpful condition perceived the exposure as being more likely to succeed in helping them reduce their anxiety. Moreover, exposure expectancy mediated the relationship between the helpful condition (but not the unhelpful condition) and willingness to engage in future exposure exercises. There were no differences between conditions on most other outcomes. Taken together, these findings suggest that SB use may not necessarily be detrimental to outcomes on an exposure-like task, as individuals were able to gather disconfirmatory evidence (one of the proposed primary mechanisms underlying exposure success) across conditions in both studies. However, clients may believe SBs to be more helpful than they actually are, and clinicians should work collaboratively with clients to identify whether judicious SB use may be appropriate and helpful (or inappropriate and detrimental) in achieving their treatment goals. The current research program has the potential to improve our understanding of the consequences of SB use and identify the ways in which cognitive behavioural therapies could be improved.

A controlled presleep experience was used in an attempt to trace waking experience in dreams. Dream reports were collected in the laboratory from 12 dreamers (half men, half women; half recallers, half nonrecallers), using the electrophysiological method of Dement and Kleitman. Following a baseline night, each dreamer was awakened on three consecutive nights during every REM period (rapid eye movement and Stage 1-ascending EEG pattern). Immediately prior to sleep on Night 3, four of the dreamers viewed an emotionally arousing film, four others viewed a slide sequence having the same content as the stressful film, and four others viewed an emotionally "neutral" film. Two independent judges, using Hall and Van de Castle's dream content analysis method and a tally system designed specifically for this study, failed to differentiate dreamers in the three groups on the basis of their dream content. Analyses of variance of dream content scores also failed to provide any evidence for differences among groups, recallers and nonrecallers, or nights. Some differences in dreaming style (e.g., total REM time, recallability) were noted. Limitations of the study and methodological problems were discussed. Posthoc analyses of dream reports with experimental situation content, dreamers' associations to their own dreams, and some clinical interpretations were included.

In recent years cognitive style has become the focus of much educational research. Many educators believe that instructional effectiveness can be maximized by utilizing the student's preferred cognitive style as a springboard for introducing new concepts as well as by restructuring educational practices so that the child learns to deal effectively with diverse cognitive styles. Early research on cognitive style focused solely on behavioral indicators. Today many researchers acknowledge that, in order to understand cognitive style, one must examine brain processing, as different styles of thinking result from the manner in which each hemisphere of the brain processes information. This study, based on the investigator's observations of reading behaviors of Mexican-American and Anglo-American children, and on an examination of available research on cognitive style and hemispheric functioning, has a threefold purpose: 1) to identify learning styles as observed in the classroom, 2) to define cognitive style in terms of neuropsychological research, and 3) to identify major factors affecting cognitive style.

Subliminal perception is defined as a process whereby a subject reports no awareness of a visual stimulus, and yet his/her verbal behavior, subjectively experienced as “guesses”, is influenced by the stimulation. Various studies have found evidence for and against subliminal perception using discrimination tasks and subjective judgments. Explanations of subliminal perception include the partial cue hypothesis, the theory of perception of structural differences, and the theory that responses to subliminal stimuli are of a semantic nature. This study was conducted to determine whether subliminal perception involves a discrimination of structural characteristics or a discrimination of the semantic quality of words prior to specific identification. It was also an attempt to find the relationship between the level of stimulus awareness and the type of response.

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