Individual differences in neural architecture supporting mental time travel

Ridgeway, Samuel 2021. Individual differences in neural architecture supporting mental time travel. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Episodic and semantic memory have been cornerstones of memory research ever since they were first described in a seminal article by Endel Tulving in 1972. Later work by Tulving posited that particularly episodic memory supported mental time travel, a process by which humans could project the self across a conceptual lifespan (however modern research has emphasised the role of semantic memory in the process). Various neurocognitive models have been proposed that attempt to explain the component processes of mental time travel. While it is now recognized that a common ‘core’ brain network underlies memory, prospection, and imagination (Schacter et al., 2017), the neural substrates of the component processes that comprise the core network supporting memory-based simulations, and the extent to which they are dissociable, are still a matter of intense debate. This thesis has demonstrated that combining diffusion MRI-based tractography with interview and self-report measures is a viable method for investigating the associations between interindividual differences in white matter microstructure and cognitive traits or tendencies related to mental time travel. The present findings provide support for the notion that episodic and semantic memory systems are at least partially separate and supported by different structurally instantiated neural pathways. However, it is also clear that they must interact and support each other within episodic construction and mental time travel. Regarding the current models of mental time travel, the results of this thesis do not provide overwhelming support to any single model. However, some evidence has been provided (linking fornix-mediated hippocampal processing to spatial components of memory in particular) that might support the scene construction hypothesis (Hassabis & Maguire, 2007). Further, present findings did not show a significant association between semantic circuitry (mediated by the ILF) and episodic future thinking – which poses a challenge to the semantic scaffolding hypothesis (Irish & Piguet, 2013). However, this is consistent with Tulving’s original notion of episodic and semantic memory (including autobiographical facts) being dissociable but interacting memory systems that are future as well as past directed.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Psychology
Subjects:	B Philosophy. Psychology. Religion > BF Psychology
Funders:	ESRC
Date of First Compliant Deposit:	19 July 2021
Date of Acceptance:	19 July 2021
Last Modified:	02 Aug 2022 01:12
URI:	https://orca.cardiff.ac.uk/id/eprint/142679

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