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Adults with autism spectrum disorder (ASD) show intact recognition (supported procedure) but impaired recall (unsupported procedure) of incidentally-encoded context. Because this has not been demonstrated for temporal source, we compared the temporal and spatial source memory of adults with ASD and verbally matched typical adults. Because of difficulties with temporal processing in ASD, we predicted ASD adults would benefit from test support for location but not temporal occurrence of studied words. We found similar levels of recognition and source memory for both groups but there was a greater effect of support on memory for location source in the ASD group. The lack of an effect of support for temporal source may simply reflect a difficulty in operationalising temporal cues.

Rehearsal strategies of adults with autism spectrum disorders (ASDs) and demographically matched typically developed (TD) adults were strategically manipulated by cueing participants to either learn, or forget each list word prior to a recognition task. Participants were also asked to distinguish between autonoetic and noetic states of awareness using the Remember/Know paradigm. The ASD group recognised a similar number of to-be-forgotten words as the TD group, but significantly fewer to-be-learned words. This deficit was only evident in Remember responses that reflect autonoetic awareness, or episodic memory, and not Know responses. These findings support the elaborative encoding deficit hypothesis and provide a link between the previously established mild episodic memory impairments in adults with high functioning autism and the encoding strategies employed.

Diminished episodic memory and diminished use of semantic information to aid recall by individuals with autism spectrum disorder (ASD) are both thought to result from diminished relational binding of elements of complex stimuli. To test this hypothesis, we asked high-functioning adults with ASD and typical comparison participants to study grids in which some cells contained drawings of objects in non-canonical colours. Participants were told at study which features (colour, item, location) would be tested in a later memory test. In a second experiment, participants studied similar grids and were told that they would be tested on object-location or object-colour combinations. Recognition of combinations was significantly diminished in ASD, which survived covarying performance on the "Color Trails Test" (D'Elia et al. "Color trails test. Professional manual." "Psychological Assessment Resources," Lutz, 1996), a test of executive difficulties. The findings raise the possibility that medial temporal as well as frontal lobe processes are dysfunctional in ASD.

To test the effects of providing relational cues at encoding and/or retrieval on multi-trial, multi-list free recall in adults with high-functioning autism spectrum disorder (ASD), 16 adults with ASD and 16 matched typical adults learned a first followed by a second categorised list of 24 words. Category labels were provided at encoding, retrieval, both or not at all. Both groups showed enhanced recall when labels were available during encoding or throughout the task. ASD individuals showed reduced recall of the second list and reduced clustering. Clustering and recall were correlated in both groups, which also showed similar levels of subjective organisation. The findings are discussed in relation to theories of frontal and medial temporal lobe contributions to memory in ASD.

The "Task Support Hypothesis" (TSH, Bowler et al. Neuropsychologia 35:65-70 1997) states that individuals with autism spectrum disorder (ASD) show better memory when test procedures provide support for retrieval. The present study aimed to see whether this principle also applied at encoding. Twenty participants with high-functioning ASD and 20 matched comparison participants studied arrays of 112 words over four trials. Words were arranged either under hierarchically embedded category headings (e.g. Instruments-String-Plucked-Violin) or randomly. Both groups showed similar overall recall and better recall for the hierarchically organised words. However, the ASD participants made less use of information about relations between words and more use of item-specific information in their recall, confirming earlier reports of relational difficulties in this population.

Memory in autism spectrum disorder (ASD) is characterised by greater difficulties with recall rather than recognition and with a diminished use of semantic or associative relatedness in the aid of recall. Two experiments are reported that test the effects of item-context relatedness on recall and recognition in adults with high-functioning ASD (HFA) and matched typical comparison participants. In both experiments, participants studied words presented inside a red rectangle and were told to ignore context words presented outside the rectangle. Context words were either related or unrelated to the study words. The results showed that relatedness of context enhanced recall for the typical group only. However, recognition was enhanced by relatedness in both groups of participants. On a behavioural level, these findings confirm the Task Support Hypothesis [Bowler, D. M., Gardiner, J. M., & Berthollier, N. (2004). Source memory in Asperger's syndrome. "Journal of Autism and Developmental Disorders, 34", 533-542], which states that individuals with ASD will show greater difficulty on memory tests that provide little support for retrieval. The findings extend this hypothesis by showing that it operates at the level of relatedness between studied items and incidentally encoded context. By showing difficulties in memory for associated items, the findings are also consistent with conjectures that implicate medial temporal lobe and frontal lobe dysfunction in the memory difficulties of individuals with ASD. (Contains 2 tables and 2 figures.)

Abstract: Autism spectrum disorders (ASDs) are characterised by a relatively specific pattern of typical and atypical memory functioning. Convergent behavioural and neuroscientific evidence indicates that this pattern of functioning may be the result of specific impairments in hippocampally mediated relational memory processes, whilst brain-mechanisms mediating item-specific memory processes remain intact. In the current paper we draw on a behavioural paradigm developed by Hunt and Seta [Hunt, R. R., & Seta, C. E. (1984). Category size effects in recall—The roles of relational and individual item information. Journal of Experimental Psychology: Learning, Memory and Cognition, 10, 454–464], which not only allowed us to determine whether individuals with ASD did indeed experience selective difficulties in relational processes, but in addition enabled us to gain insights into the severity of this impairment. Our results suggest that whilst individuals with ASD employ relational memory processes atypically, this impairment seems restricted to situations in which such processes need to be deployed spontaneously to facilitate memory. Under situations that provide environmental support for the processing of relational information, individuals with ASD did demonstrate the ability to employ such processes relatively effectively. These findings provide further support for the ‘Task Support Hypothesis’ and suggest that relational memory processes may in principle be functionally intact despite not being triggered by the same environmental situations as in typical development. [Copyright &y& Elsevier]

Single trial methods reveal unimpaired free recall of unrelated words in Asperger’s syndrome (AS). When repeated trials are used (free recall learning), typical individuals show improved recall over trials, subjective organisation of material (SO) and a correlation between free recall and SO. We tested oral (Experiment 1) and written (Experiment 2) free recall over 16 trials in adults with AS and typical individuals. Across both experiments AS participants showed marginally diminished recall. Poorer SO was seen in the Asperger group only in Experiment 2, but in both experiments, individual differences in SO in the Asperger group were less likely to converge over trials. This lack of convergence suggests that the AS group organise material in idiosyncratic ways. [ABSTRACT FROM AUTHOR]

Abstract: have shown a small but significant impairment of autonoetic awareness or remembering involved in the episodic memory experiences of adults with Asperger’s syndrome. This was compensated by an increase in experiences of noetic awareness or knowing. The question remains as to whether the residual autonoetic awareness in Asperger individuals is qualitatively the same as that of typical comparison participants. Three experiments are presented in which manipulations that have shown differential effects on different kinds of conscious awareness in memory in typical populations are employed with a sample of adults with Asperger’s syndrome. The results suggest that the experiences of remembering reported by such individuals, although reduced in quantity, are qualitatively similar to those seen in the typical population. The results are discussed in the context of current theories of awareness in episodic memory. [Copyright &y& Elsevier]

Memory difficulties in autism are observed mainly on measures like free recall, where test procedures provide no support for memory. When support is present, such as in cued recall, difficulties are less evident. Such observations may explain the mixed findings on source memory in autism. Bennetto, Pennington and Rogers (Child Development, 67, 1816–1835) found increased earlier-list intrusions in a multi-list free-recall paradigm (support absent), yet Farrant, Blades and Boucher (Journal of Autism and Developmental Disorders, 28, 43–50) reported no impairment in identification of who had spoken a particular word at study (support present). We tested the effects on source memory of presence or absence of support for source in participants with Asperger's syndrome. The Asperger participants' overall deficit in source memory was largely eliminated when source was supported at test. [ABSTRACT FROM AUTHOR]

Two experiments compared incidental (implicit) and intentional (explicit) memory performance in adults with Asperger's syndrome and individually matched controls. Experiment 1 involved perceptual tests using word fragment cues, following study tasks in which the participants either generated the words from contextual cues or read the words alone, with no contextual cues. Experiment 2 involved conceptual tests using paired associate cues, following study tasks in which the paired associates were rated either for their relatedness or for their readability. Performance in both the incidental tests was similar for both groups. Performance in both the intentional tests was also similar for both groups, with one exception. The adults with Asperger's syndrome were more likely to falsely recall words that had not actually been studied. These findings further delimit the nature of memory impairments in adults with Asperger's syndrome, which seem restricted to certain aspects of episodic memory that include the tendency to make more intrusion errors in recall. [ABSTRACT FROM AUTHOR]