The Relationships of the Metrics of Graph Theoretical Analysis of Resting-state Functional Connectivity to Memory Test Performance in Cognitively Normal and Mild Cognitive Impairment Individuals

Show simple item record

dc.contributor.advisor Kirk, I en
dc.contributor.advisor Tippet, LJ en
dc.contributor.author Groult, Genevieve en
dc.date.accessioned 2020-05-11T03:33:04Z en
dc.date.issued 2020 en
dc.identifier.uri http://hdl.handle.net/2292/50607 en
dc.description Full Text is available to authenticated members of The University of Auckland only. en
dc.description.abstract Alzheimer’s disease (AD) is a chronic degenerative brain disorder with an insidious, gradual onset and a progressive course, culminating in the loss of functional connectivity (FC) and atrophy within the brain. Amnestic Mild Cognitive Impairment (aMCI), the prodromal stage of AD is characterised by impairments in episodic memory, and delayed recall of visual and auditory information. Changes in resting-state (rs) FC are observable across visual and auditory networks when comparing aMCI populations with cognitively normal groups. Graph theory, an emerging mathematical tool provides a means to measure and visualise the connectivity between nodes or regions within the brain. Graph theoretical analysis of regions within functional neural networks allows us to determine the degree of connectivity or 'betweenness' between nodes, the ratio of connections or 'clustering' between a node and its neighbours, and the path length and degree of centrality between a node and all other nodes within a graph. There is a limited amount of research applying graph theoretical analysis to assess resting-state FC between cognitively normal (HC) and aMCI populations, as most studies involve taskbased fMRI, or AD populations. Here, we assess the relationship between rsFC and graph theoretical metrics, and their correlations with neuropsychological test results across an aMCI group and a healthy control (HC) group. We applied graph theoretical metrics to 116 ROIs across the connectome, assessing betweenness (BC), clustering coefficient (CC), and degree of centrality (DoC) at global and individual nodal levels. This study cohort comprised 22 participants, who fell into two clinical groups: HC (n = 11), and aMCI (n = 11). Our results revealed decreased rsFC in aMCI compared to HC, specifically with lower level in performance across all neuropsychological tests for the aMCI group, and a negative correlation between the decrease in test scores and BC, CC and DoC for aMCI individuals. The cognitive processes measured through these behavioural tests demonstrate a relationship between decreased performance in delayed visual and verbal memory tasks and functional connectivity. The combination of graph theoretical analysis, with structural functional magnetic resonance imaging (fMRI) and neuropsychological testing may provide us with the ability to identify areas of strength and weakness for rehabilitation, and longitudinal observation of global and nodal alterations to functional connectivity associated with aMCI. en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof Masters Thesis - University of Auckland en
dc.relation.isreferencedby UoA en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. en
dc.rights Restricted Item. Full Text is available to authenticated members of The University of Auckland only. en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ en
dc.title The Relationships of the Metrics of Graph Theoretical Analysis of Resting-state Functional Connectivity to Memory Test Performance in Cognitively Normal and Mild Cognitive Impairment Individuals en
dc.type Thesis en
thesis.degree.discipline Psychology en
thesis.degree.grantor The University of Auckland en
thesis.degree.level Masters en
dc.rights.holder Copyright: The author en
pubs.elements-id 801051 en
pubs.org-id Science en
pubs.org-id Psychology en
pubs.record-created-at-source-date 2020-05-11 en


Files in this item

Find Full text

This item appears in the following Collection(s)

Show simple item record

Share

Search ResearchSpace


Browse

Statistics