Objectives: (1) To disentangle the relative importance of information-processing deficits from self- and social-processing deficits in ASD using episodic and semantic memory tasks matched for level of complexity. (2) To determine the neuropsychological co-variates of memory patterns in ASD, using in-depth clinical tests of social and cognitive processing.
Methods: Participants included 40 8-18 year-old subjects with ASD and 40 age, sex and IQ-matched controls. Autism diagnoses were confirmed using ADOS (Lord et al., 1999) and ADI-R assessments (Lord et al., 2003), and all subjects completed the Social Responsivity Scale (SRS) (Constantino, 2000) and Social Communication Questionnaire (SCQ) (Berument et al., 1999). Sub-tests from the NEPSY-II (Korkman et al., 2007) were used to obtain standardized measures of social and non-social semantic memory and organizational ability. The experimental tasks included a Levels-of-Processing task (based on Toichi et al., 2002) and a narrative recall task (based on Crane and Goddard, 2008) comparing memory for self, mother and favorite fictional character.
Results: Preliminary results, based on 15 ASD participants, support a self-reference effect (p = 0.018), with memory for self greater than memory for mother (p=0.056) and favorite fictional character (p=0.012) (contrary to Toichi et al., 2002 but in line with Lombardo et al., 2009; Henderson et al., 2009), thus providing support for the social-impairment hypothesis of autism. Further data collection, between-group and regressional analyses are underway to provide a more detailed picture of the underlying social and cognitive skills shaping the discrepant memory patterns in ASD.
Conclusions: By determining whether deficits in episodic memory in ASD arise from a particular impairment in organizing events in the world around their sense of self, or whether they are driven by broader information-processing deficits, our study aims to advance our understanding of the social communication deficit seen in autism as it unfolds over time, and to further specify targeted interventions.