Access Type

Open Access Dissertation

Date of Award

January 2019

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Psychology

First Advisor

Noa Ofen

Abstract

Objective The hippocampus (Hc) is essential for memory and vulnerable to the sequelae of premature birth. Relationships between subcomponents of the Hc and memory performance have been documented in adults. Yet little is known about the generalization of these findings to young children, whether term or preterm-born. This tripartite investigation focused on Hc subregion and subfield volumes, a potential latent construct for episodic memory, and the relationship between Hc volume and memory performance across birth weight (BW) and gestational age (GA).

Participants and Methods Forty-eight children (20 preterm), ages 5-7, completed an MRI scan and several episodic memory tasks. An additional 18 children (13 preterm) completed the memory tasks but did not undergo an MRI. Manual demarcation was completed with high reliability for total Hc, Hc subregion, and Hc subfield volumes. A factor analysis was conducted to form a latent construct for episodic memory. Bivariate correlations and general linear modeling analyses were used to evaluate volume-performance relationships.

Results Preterm-born children had significantly larger Hc Head volume than term born children. No other significant associations were observed between GA or BW and Hc subcomponents. Factor analysis yielded a three-factor structure, including a factor we termed episodic memory. Factor scores did not correlate with BW or GA. The episodic memory factor significantly related to Hc Body, Dentate Gyrus, and Subiculum volumes in the whole MRI sample.

Conclusions The significant effect in the Hc Head may partially be due to the unique vulnerability of the Hc subregion CA1, which is relatively more largely represented in the Hc Head than the Hc Body. Although we provide limited evidence for differences in regional volumes between term and preterm-born children at this age, our findings do support the notion that specific relationships between Hc volume and memory are present in young children.

Included in

Psychology Commons

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