Use of an Experimental Design to Examine Factors That Contribute to Episodic Memory Deficits in Children with High Functioning Autism

Background: Children with autism spectrum disorders (ASD) have been found to demonstrate impairment in episodic memory (EM).  Factors that could contribute to or magnify EM impairment in ASD have not been examined. 

Objectives: To examine factors, specific to ASD, that potentially influence EM performance on conventional assessments such as impaired expressive language, the method of prompting (verbally or visually) for memory recall, the salience of the event to the individual, and various cognitive factors.

Methods: This study examined 62 children (56 males, 6 females), aged 6-13 years, with High-Functioning ASD assessed for participation in a study using CBT to treat core ASD symptoms.  During the administration of the experimental assessment, participants were shown a series of five slide shows, each of which depicts an emotion (happy, sad, angry, nervous, and embarrassed) and consists of a story that ends with a film of a child portraying the emotion which corresponds to the story.  Methods of recall were systematically varied as participants were then asked to recall the stories verbally and non-verbally to examine the role of expressive language in memory recall, with a visual or verbal prompt to understand if method of cueing effects memory recall, and events that were of either high or low preference to determine if salience impacts quantity and quality. Additionally all participants were administered the WISC to determine their IQ.  

       Correlations were run using the EM measure’s T scores and the participant’s scores on the WISC (full scale IQ and subscales) to determine the relationship between various cognitive processes and EM performance. An Analysis of Variance (ANOVA) was also run to examine if participants demonstrated a difference in performance in various conditions of recall, thus implicating potential confounds in EM assessment.  

 Results: Verbal ability and working memory scores as determined by WISC subscales were found to correlate with all EM conditions and total scores with the exception of the non-verbal response.  The ANOVA indicated that there are differences in recall across all four conditions and that the number of details recalled accurately as well as the chronological order of recall are impacted by the salience of the event and method of recall.  

Conclusions: The EM measure sought to examine if expressive language deficits, method of recall and salience of the event impacted EM recall in children with ASD.  It was found that both the salience of the incident to the individual and the role of expressive language impacted the participant’s memory for details and sequential recall of events. It appears that children with ASD may recall more details than they are able to verbalize without a given structure. Additionally, cognitive factors such as working memory and verbal ability may also impact EM performance. The results suggest that the presentation and severity of EM deficits in children with ASD could be due to or impacted by outside cognitive factors.