Recall and Recognition of Episodically-Defined Word Pairs: Further Evidence of a Relational Binding Difficulty In ASD

Background: Individuals with ASD resemble healthy typical older adults in experiencing greater difficulty on unsupported memory tasks such as recall rather than supported tasks such as recognition.  This reliance on Task Support has also been demonstrated for incidentally encoded context and for semantic relatedness between studied items and incidental context. Bowler, Gaigg & Lind (2011) argue that these difficulties result from a diminished capacity for relational binding in ASD which may also underlie diminished episodic recollection in this population.  Naveh-Benjamin (2000) reported greater impairment in recognition of pairs of unrelated words than single words by older typical adults, reflecting an associative deficit in this population.  Using a modification of Naveh-Benjamin’s task, we predicted undiminished recognition but diminished recall of unrelated word pairs in adults with ASD.

Objectives: To compare recall and recognition of unrelated word pairs in high-functioning adults with ASD and typical comparison participants.

Methods: Groups of about 16 adults with ASD and verbal ability matched typical individuals were shown lists of 12 (Experiment 1) or 16 (Experiment 2) pairs of weakly-associated words and asked to try to remember as many of the pairs as they could. At test, in Experiment 1, they were asked to recall as many of the pairs as they could. In Experiment 2, they were presented with cards each bearing one studied word, together with 16 lure cards and asked to make up as many of the studied pairs as they could.

Results: In the recall test, ASD participants could recall 58% of the word pairs compared to a recall rate of 80% by the comparison group, a difference that was significant (p<.05). By contrast, the correct pair recognition in the ASD group was not significantly different from that of the comparison group (45% vs 42%).

Conclusions: The findings extend the Task Support Hypothesis of memory in ASD to the recall of episodically-defined pairings of stimuli and supports the view put forward by Bowler et al. (2011) that atypical memory performance in ASD is a reflection of relational binding difficulties.