Short-Term Memory Integration in Adults with Autism Spectrum Disorder

Poster Presentation
Friday, May 3, 2019: 5:30 PM-7:00 PM
Room: 710 (Palais des congres de Montreal)
M. Ring1, B. Guillery-Girard2, P. Quinette3, S. B. Gaigg4 and D. M. Bowler5, (1)Department of Child and Adolescent Psychiatry, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, (2)Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000 Caen, France, Caen, France, (3)Inserm—EPHE, Université de Caen-Normandie, Unité E0218, Laboratoire de Neuropsychologie, CHU Côte de Nacre, 14033 Caen Cedex, France, Caen, France, (4)City, University of London, London, United Kingdom, (5)Autism Research Group, City, University of London, London, United Kingdom
Background: Adults with Autism Spectrum Disorder (ASD) show difficulties in long-term memory, which are assumed to result from altered relational binding (Bowler et al., 2011). Relational binding is the process that forms a coherent episodic representation out of the elements of an experience. Recently, two studies suggested additional difficulties in short-term memory in ASD, when autistic adults were asked to remember the temporal order of the presentation of digits and words (Poirier et al., 2011) or dot locations in a grid (Bowler et al., 2016). However, so far it is not clear how well ASD participants can form associations between letters and grid locations using colour coding. Moreover, patterns of strength and difficulties in short-term and long-term memory in ASD would help elucidate the different brain regions affected in ASD.

Objectives: This task aimed to test 3-way (object, colour, location) short-term memory binding in ASD. Because of their known difficulties with long-term memory binding, it was predicted that ASD adults would show difficulties with short-term memory binding compared to matched TD adults. In addition, it was of interest to investigate the types of errors made by participants.

Methods: Fifty-three ASD and 52 typically developing (TD) participants matched on gender, chronological age (CA; MCA = 43.03), and intelligence quotient (IQ; MFIQ = 111) were tested on a task asking them to memorise the positions of letters in the cells of a grid. The letters were presented in different colours in the centre of the grid and participants were asked to imagine the letter in the grid cell with the cross of the same colour as the letter. For a subgroup of 33 TD and 34 ASD individuals, still well-matched in terms of gender, chronological age (CA; MCA = 43.14), and intelligence quotient (IQ; MFIQ = 113), we investigated which types of errors they made.

Results: ASD individuals showed significantly lower accuracy rates (M = 0.79, SD = 0.16) compared to TD individuals (M = 0.86, SD = 0.14) in forming the letter-location associations via colour coding (t(103) = 2.55, p < .05, Cohen’s d = 0.50). Groups did not differ significantly in terms of the types of errors they made.

Conclusions: This study suggests that 3-way relational binding difficulties also occur in short-term memory in addition to long-term memory in ASD. A direct comparison of short-term memory and long-term memory in ASD is a task for future research. However, the current study suggests that next to the frontal lobes and the medial temporal lobes, specifically the hippocampus, parietal brain regions might also be involved in atypical memory functioning in ASD, given their role in visual short-term memory (Sheremata et al, 2018).