No description available.

No description available.

No description available.

The capacity to mentally transcend the present moment affords the opportunity to relive former pleasures or preview the perils of things to come. According to the theory of embodied cognition, these imaginary events are made possible by the reactivation of the modality-specific sensory-motor components that accompany interaction with the environment (Barsalou, 1999, 2008; Wilson, 2002). But what happens when our mental simulations deviate from veridical experience? Guided by the observation that imagining the self from an outside point-of-view is a regular occurrence in the mental world (Nigro & Neisser, 1983), this thesis explored the sensory-motor activities that accompany first- and third-person imagery. As first-person (cf. third-person) simulations are closer in character to actual experience, it was anticipated that events imagined from this point-of-view would be accompanied by more pronounced embodied effects than those imagined from a third-person perspective. Online (i.e., during imagery) measures demonstrated that neural (Chapter 2) and motor (Chapter 3) activities were greater when imagining experiences from a first-person (cf. third-person) perspective. Extending the exploration of embodiment to offline (i.e., after imagery) effects, it was evidenced that simulated temperature contaminated person perception judgments (Chapter 4) and imaginary ingestion exacerbated consumption of unhealthy foods (Chapter 5), but only when the relevant sensory information was simulated from a first-person point-of-view. A final study contextualized these findings, identifying the natural occurrence of each perspective as well as individual differences that influence the vantage point most commonly adopted during spontaneous mental imagery. Taken together, these results suggest that first-person simulations are more body-based than their third-person counterparts. Imbued with theoretical and practical implications, the current thesis identifies a potential mechanism by which first- and third-person simulations give rise to disparate cognitive and behavioural outcomes, and furnishes a more nuanced understanding of embodied cognition.

Age-related declines in cognitive functioning have been well documented, however, there are vast individual differences in the age of onset and magnitude of these changes. This observation has spurred the investigation of the potential risk factors for cognitive decline. Chronic elevations of the steroid hormone cortisol have been shown to compromise hippocampal- and frontal cortex- dependent cognitive tasks in rodents, non-human primates and Cushing’s disease patients. Several studies have extended these findings to investigate possible associations between cortisol and cognition in aging human populations. However, these previous examinations of the role of cortisol in cognitive aging have been hampered by the predominant use of single time-point measures of cortisol, small sample sizes, limited age ranges and/or constrained cognitive testing batteries. The present cross-sectional study investigated the relationship between basal cortisol levels, indexed by a 24-hr free cortisol to creatinine ratio, and cognitive functioning on twelve cognitive outcomes in a sample of 1,853 non-demented adults aged 18 to 93 years. The results showed that elevated cortisol levels had small but significant negative effects on verbal learning and working memory performance across the lifespan and significant negative effects limited to older age on a measure of speeded processing. Longitudinal investigation is warranted to examine if within-person changes in cortisol level predict cognitive change.

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

published_or_final_version / Psychology / Master / Master of Philosophy

published_or_final_version / abstract / Psychiatry / Master / Master of Philosophy

published_or_final_version / Psychology / Master / Master of Philosophy

published_or_final_version / Educational Psychology / Master / Master of Social Sciences