An investigation of episodic future thinking, episodic foresight and prospective memory in children with Autism Spectrum Disorder

Abstract

Background and Objectives: The overall objective of the current thesis was to investigate three forms of prospection in children with autism spectrum disorder (ASD), namely episodic future thinking, episodic foresight and prospective memory (PM), using three empirical studies. While few past studies have found ASD-related impairments in episodic future thinking, there is limited understanding of the mechanisms that might underpin these impairments in this clinical group. The aim of the first empirical study was therefore to investigate whether difficulties in two potential cognitive mechanisms, specifically scene construction and self-projection through time, might contribute to episodic future thinking deficits in children with ASD. In addition, no studies to date have examined the practical application of episodic future thinking, which involves taking steps in the present in light of imaginations of the future (referred to as episodic foresight in the current thesis), in individuals with ASD. Thus, the second empirical study aimed to investigate whether episodic foresight might be compromised in children with ASD, and possible cognitive factors that might underpin any identified episodic foresight deficits. Furthermore, while time-based PM has consistently been shown to be impaired in ASD, findings on event-based PM have been mixed in the literature. The cognitive contributors to impairments in PM also remain unclear. Hence, the aim of the third empirical study was to investigate event-based and time-based PM, as well as their potential contributing factors, in children with ASD. Lastly, given the importance of episodic foresight and PM on daily functioning argued in the literature, the current thesis also explored the relationships between these forms of prospection and functional capacity in children with ASD. Method and Results: Children with high-functioning ASD (i.e., IQ > 80) aged 8 to 12 years and age- and IQ-matched healthy controls were recruited for the current research project. Study 1 (n = 37 ASD, 60 controls) showed that impairments in episodic future thinking were linked to difficulties in scene construction, rather than self-projection through time. In addition, Study 2 (n = 40 ASD, 55 controls) provided novel evidence of an intact capacity to take appropriate steps in the present in anticipation of potential future problems in the ASD group. However, children with the disorder demonstrated an impaired capacity to subsequently implement actions at specific future points that allowed successful problem resolutions, therefore result in a failure in episodic foresight. The impairments in implementing actions at appropriate future points were not attributable to retrospective memory or executive functioning deficits. Study 3 (n = 32 ASD, 42 controls) revealed pervasive deficits in both event-based and time-based PM in children with ASD, and indicated that these deficits were related to difficulties in executive functioning and retrospective memory for PM task content. Finally, episodic foresight and PM were not found to be associated with functional capacity in the ASD group. Conclusions: The current thesis provided novel insights into the unique profile of impairments across different forms of prospection in children with ASD. Further investigations will be needed to clarify how and why specific impairments in these forms of prospection are apparent in children with ASD, specifically whether these impairments may be attributable to common underlying deficits. Future research in this area will be beneficial in contributing to the development of targeted interventions that aim to improve daily functioning in this clinical population.