Poster #6 - Cortical Thickness is Related to Episodic Memory in Early Childhood

• In Event: Poster Session 09

Abstract

The ability to remember details of past experiences (i.e., episodic memory) relies on a network of brain regions. Extant neuroimaging research in adults and adolescents has identified multiple regions for which cortical thickness is associated with episodic memory performance. For example, cortical thickness of orbitofrontal regions has been linked to delayed recall performance in 8 to 19 year-olds (Østby et. al., 2012). However, little research has looked at this relation in younger children. Considering that early childhood is marked by rapid improvements in episodic memory (e.g., Riggins, 2014) and complex (i.e., non-linear) changes in cortical thickness (Ducharme, et al., 2016), more research is needed to determine whether and how structural measures of cortical brain development relate to memory performance during this developmental stage. To address this gap, the current study aims to examine the link between cortical thickness and latent episodic memory in 4- to 8-year old children.

This study used data from a larger longitudinal study examining episodic memory development and the brain during early childhood (blinded for review). Including a latent memory performance measure estimated from four separate memory tasks (blinded for review) and cortical thickness derived from structural MRI data at the first time point of the study. A total of 176 4- to 8-year-old children provided usable data. We selected 12 bilateral a priori regions on interest (ROI) that have been previously associated with memory development (e.g., Ghetti & Bunge, 2012), including prefrontal brain regions (i.e., IFG, OFC, and ACC), posterior parietal cortex (including precuneus), lateral occipital cortex (LOC), parahippocampal gyrus, and cerebellum.

Results revealed that cortical thickness of left precuneus (β=-.19, p<0.05), right anterior cingulate (β=-.07, p<0.05) and right lateral orbitofrontal cortex (β=.16, p<0.01) negatively related to participants’ episodic memory performance. In contrast, right pars orbitalis (β=.09, p<0.01) is positively related to participants’ episodic memory performance. After controlling for sex and age, only the relations between right anterior cingulate (β=-.07, p<0.01) and right pars orbitalis (β=.07, p<.01) remained statistically significant. Specifically, greater anterior cingulate cortical thickness was associated with lower memory scores and greater pars orbitalis cortical thickness was associated with higher memory scores.

The different directions in the effects of anterior cingulate versus . pars orbitalis are consistent with previous findings documenting different and often nonlinear developmental trajectories during brain maturation among cortical regions (Ducharme, et al., 2016). To assess these potential nonlinear trajectories, data collected at two subsequent time points will be analyzed to characterize longitudinal changes in the relation between cortical thickness and memory development.We will also expand our analyses to include additional ROIs using a whole brain vertex by vertex analysis to identify all cortical regions linked to early childhood memory performance.

Strengths of this project include 1) use of a latent memory measure estimated from participants’ performances across four different behavioral memory tasks as it reflects the shared memory construct across tasks supported by a unified episodic memory network (Vincent et al., 2006); and 2) a previously under-explored, yet developmentally interesting age group.

Authors

• Yuqing Lei, University of Maryland - College Park
  Presenting Author

• Tamara Lynn Allard, University of Maryland - College Park

• Zehua Cui, University of Maryland - College Park

• Kelsey Leigh Canada, Wayne State University

• Tracy Riggins, University of Maryland - College Park