Mechanisms underlying deficits in autobiographical memory retrieval in Autism Spectrum Disorders

Background: Autobiographical memory (AM)  retrieval is an essential human ability, important for understanding oneself as an enduring entity and  understanding how other people think, feel and act. AM comprises two components: semantic AM which encompasses biographical personal information (e.g., names, addresses and trait information) and episodic AM which contains personally experienced events. While there is evidence for a specific (i.e., episodic) memory deficit in adults with ASD (Goddard et al, 2007), there is some indication that memory for personal semantic information is preserved (Crane & Goddard, in press).  

Objectives:

We explored the nature of AM deficits in children with ASD, focusing on different time periods and the semantic/episodic components of AM. We also investigated the potential mechanisms underlying AM difficulties, in particular, central executive function, visual memory and emotion processing.

Methods:

35 children with an ASD between the ages of 8 and 16 and 35 typically developing children matched for age, gender and IQ participated in this study. Memory was assessed on  a word cueing task, and two semi structured interviews: one examining memory for recent and remote events and the other systematically examining semantic and episodic memory across different life time periods. Control measures included verbal fluency, vocabulary and general memory. Components of central executive function were examined with the Wisconsin Card Sorting, Stroop, Tower of London and Junior Hayling tasks.
Results: The ASD group showed difficulties in retrieving both episodic and semantic AMs and also required substantially more prompting. These effects were largely independent of general memory ability. The strongest predictor of poor autobiographical memory was performance on the Wisconsin Card Sorting and Tower of London tasks

Conclusions: Certain components of central executive function, i.e., set shifting and  planning, underlie difficulties in autobiographical memory retrieval in children with an ASD. The developmental pathway of these deficits is discussed.