A Comparison between Traditional and Musical Working Memory Assessments and the Associated Cognitive and ASD Behavioural Correlates

Background: Autism Spectrum Disorder (ASD) is often associated with executive functioning difficulties, which can be exacerbated by autism-related symptoms such as restricted and repetitive behaviours. Individuals with ASD also tend to possess strengths and weaknesses in visual-spatial and verbal skills, respectively. Music perception is considered a strength in ASD, with most studies investigating perception of music-evoked emotions, pitch and melody, and long-term musical memory. One aspect of music-related cognition that has yet to be systematically assessed in ASD is musical working memory, and how it relates to cognition and behaviour.

Objectives: Aim 1): Compare the performance on traditional and musical short-term working memory tests to examine whether music could be used as an alternative assessment modality of working memory in ASD. Aim 2): Compare the cognitive (i.e., visual-spatial and verbal skills) and behavioural ASD correlates (i.e., restricted and repetitive behaviours) of traditional vs. musical short-term working memory in children with ASD.

Methods: Fifty-nine children with ASD participated in this study (age= 9-16, M=12.37, SD=2.11, male n=51). Aim 1): The Working Memory Index (WMI) subtests (i.e., Digit and Picture Span) of the Weschler Intelligence Scale for Children-Fifth Edition (WISC-V) were used as measures of traditional working memory. To assess musical working memory (MWM), sequences of 3, 4, and 5 pitches were presented in pairs to participants who were asked to identify whether sequence-pairs were similar or different. Total performance (3,4, and 5 pitch sequences combined) on the MWM task was calculated as Hits minus False Alarms (Hit-FAs). Aim 2): The Verbal (VCI) and Visual Spatial (VSI) Indices of the WISC-V (cognitive correlates) as well as the Restricted Interests and Repetitive Behavior (RIRB) sub-scale score (ASD behavioural correlate) of the Social Responsiveness Scale-Second Edition (SRS-2) were correlated with both the MWM task total performance (Hit-FAs Total) and the WMI scores.

Results: Aim 1): Paired sample t-tests (using standardized values) revealed that participants performed significantly better on the MWM task (M=.52, SD=.32) than on the Digit Span (M=.12, SD=1.09, p = .013) and the Picture Span (M=.14, SD=1.02, p = .009) subtests of the WISC-V. Aim 2): Significant correlations were found between MWM task performance and the VSI (p=.001) and the RIRB sub-scale scores (p=.02). MWM task performance was not significantly correlated with the VCI score (p=.46). In comparison, the WMI score was significantly correlated with the VCI (p< .00), the VSI (p<.00), and the RIRB sub-scale scores (p=.05).

Conclusions: Our findings reveal that children with ASD performed better on a MWM task in comparison to traditional working memory tasks. Furthermore, both traditional and musical working memory were associated with visual-spatial skills, a well-documented strength in ASD, and with RIRBs, which are related to executive functioning. Furthermore, in comparison to traditional working memory tasks, musical working memory seems independent of verbal abilities. Results provide preliminary evidence for the use of music as a strength-based modality to assess the working memory abilities of children with ASD, which may be underestimated by traditional cognitive testing relying on verbal skills often impaired for this population.