Neural Connectivity and Episodic Memory in Autism Spectrum Disorder: A Literature Review

Abstract

Introduction: There is a growing interest in the social and biological context of episodic memory in children with autism spectrum disorder (ASD). Research has previously found that episodic memory deficits are overrepresented in this population. In an attempt to learn why children with ASD are disproportionately impacted by episodic memory impairments, this paper explores literature from 1970-2020 concerning the relationship between functional connectivity (FC), effective connectivity (EC) and structural connectivity (SC) and episodic memory in children with ASD.

Methods: The method of this review involved an extensive literature search in scientific databases for experimental studies and magnetic resonance imaging (MRI) data pertaining to episodic memory in children with ASD. The literature review was conducted by searching for literature in electronic databases (Google Scholar, PubMed and MEDLINE) using the following search words: “ASD and memory,” “episodic memory in ASD,” “connectivity in ASD”.

Results: In the studies reviewed, children with ASD consistently underperformed on episodic memory tasks relative to typically developing children. Additionally, the MRI scans of the children with ASD showed hyper- and hypoconnectivity of brain regions across the three connectivity metrics. The results indicated that the abnormalities seen in the FC, SC, and EC of children with ASD is an area of research and intervention opportunity for clinicians.

Discussion: Research has found that interventions introduced early to children with autism have the potential to reduce symptoms of ASD before adulthood. Therefore, it is important that early interventions related to improving episodic memory are introduced to children early on to increase quality of life later. Additionally, future research must explore if connectivity abnormalities contribute to ASD or if it precedes ASD diagnosis.  As a result, clinicians may also consider adding episodic memory deficits to the diagnostic criteria for ASD since it is overrepresented in this population.

Conclusion: Clarifying the relationship between ASD, connectivity, and episodic memory will improve the quality of life of children with ASD in the future. This understanding will have broader implications in children and adults with ASD who struggle with episodic memory in terms of improving their experience in education, work and personal life.