Abstract
Memory functioning in Autism Spectrum Disorder (ASD) is characterized by impairments in the encoding of relational but not item information and difficulties in the recollection of contextually rich episodic memories but not in the retrieval of relatively context‐free memories through processes of familiarity. The neural underpinnings of this profile and the extent to which encoding difficulties contribute to retrieval difficulties in ASD remain unclear. Using a paradigm developed by Addis and McAndrews [2006; Neuroimage, 33, 1194–1206] we asked adults with and without a diagnosis of ASD to study word‐triplets during functional Magnetic Resonance Imaging (fMRI) scanning that varied in the number of category relations amongst component words. Performance at test confirmed attenuated recollection in the context of preserved familiarity based retrieval in ASD. The results also showed that recollection but not familiarity based retrieval increases as a function of category relations in word triads for both groups, indicating a close link between the encoding of relational information and recollection. This link was further supported by the imaging results, where blood oxygen level dependent (BOLD) signal responses in overlapping regions of the inferior prefrontal cortex were sensitive to the relational encoding manipulation as well as the contrast between recollection versus familiarity based retrieval. Interestingly, however, there was no evidence of prefrontal signal differentiation for this latter contrast in the ASD group for whom signal changes in a left hippocampal region were also marginally attenuated. Together, these observations suggest that attenuated levels of episodic recollection in ASD are, at least in part, attributable to anomalies in relational encoding processes. Autism Res 2015, 8: 317–327. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.
Highlights
The broader cognitive profile of Autism Spectrum Disorder (ASD) is well known to include a pattern of memory difficulties that holds clues to the neuropathology underlying the disorder and has important implications for the design of effective educational programs [see Boucher & Bowler, 2008; Bowler, Gaigg, & Lind, 2011; Boucher, Mayes, & Bigham, 2012; Gaigg & Bowler, 2012 for comprehensive reviews]
A 2 (Group: ASD vs. typically developing (TD)) 3 3 (Triad Type: 0-link vs. 1-link vs. 2-link) analysis of variance (ANOVA) of reaction times yielded a main effect of Triad Type (F(2,44) 5 9.55, P < 0.001) that was due to slower responses during 0-link than 1-link (t = 2.79, df = 24, P < 0.05) or 2-link triads (t = 3.84, df = 24, P < 0.01), which in turn did not differ significantly from one another (t = 1.54, df = 24, P 5 0.14)
This pattern was the result of participants generally responding most accurately to 0-link triads and least accurately to 2-link triads with the ASD group performing worse than the TD group on 2-link triads (t = 2.89, df = 22, P < 0.01) but not 0-link (t = 1.00, df = 22, P 5 0.33) or 1-link triads (t = .28, df = 22, P 5 0.78)
Summary
The broader cognitive profile of Autism Spectrum Disorder (ASD) is well known to include a pattern of memory difficulties that holds clues to the neuropathology underlying the disorder and has important implications for the design of effective educational programs [see Boucher & Bowler, 2008; Bowler, Gaigg, & Lind, 2011; Boucher, Mayes, & Bigham, 2012; Gaigg & Bowler, 2012 for comprehensive reviews]. When individuals with ASD do recall previously encountered material they frequently fail to retrieve contextual details associated with the study episode such as where, when, how or from whom they have learned a particular fact [Bowler, Gardiner, & Berthollier, 2004; Hala, Rasmussen, & Henderson, 2005; Lind & Bowler, 2009; O’Shea, Fein, Cillessen, Klin, & Schultz, 2005; Russell & Jarrold, 1999] Their recall of autobiographical memories tends to be relatively void of contextual details that characterizes the personally experienced past [Crane & Goddard, 2008; Crane, Goddard, & Pring, 2009; Goddard, Howlin, From the Department of Psychology, City University London, London, EC1V, 0HB, UK (S.B.G.D.M.B.B.C.-M.,); Institute of Psychiatry, King’s College London, London, SE5, 8AF, UK (C.E.D.G.M.) INSAR. Tests of recognition memory that require participants to discriminate studied from novel stimuli pose relatively few difficulties [Barth, Fein, & Waterhouse, 1995; Beversdorf, et al, 2000; Boucher, Cowell, Howard, Broks, Mayes, & Roberts, 2005; Bowler, Gaigg, & Gardiner, 2008b; Bowler, Gardiner, & Grice, 2000; Bowler, Gardiner, & Gaigg, 2007; Salmond, Ashburner, Connelly, Friston, Gadian, & Vargha-Khadem, 2005]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
