Visuo-spatial construction trajectories in Fragile X Syndrome (FXS) and Autism Spectrum Disorders (ASD): Evidence of cognitive heterogeneity within neurodevelopmental conditions.
Navon tasks show that autism and fragile X each leave a different visual fingerprint, and mental age can hide the fragile X print.
01Research in Context
What this study did
The team gave Navon puzzles to kids with fragile X, autism, both, or neither.
They watched how each group built the pictures over time.
Mental-age scores were added to see if delays explained the patterns.
What they found
Every group had its own visual building path.
Kids with fragile X alone looked almost typical once mental age was counted.
Kids with autism still showed a unique style even after the same adjustment.
How this fits with other research
Faso et al. (2016) saw the same split paths a year earlier, but without the mental-age fix.
McGrath et al. (2012) and Edgin et al. (2005) say spatial skills in autism are fine; this paper shows the style is different, not better or worse.
Cardillo et al. (2022) also found an autism-only visual signature on a different drawing test, backing the idea that diagnosis shapes how kids see and build.
Why it matters
When you test visual skills, score the route the child takes, not just the final product. A fragile X profile may vanish once you account for mental age, but an autism profile sticks around. Use this to pick targets: fine-motor or global planning, not just correct answers.
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02At a glance
03Original abstract
BACKGROUND/AIMS: There have been discrepancies reported in visuo-spatial construction ability in children with Autism Spectrum Disorders (ASD), fragile X Syndrome (FXS) and those with a comorbid diagnosis of FXS and ASD (AFXS). This study aimed to provide a better understanding of the visuo-spatial processing styles in these heterogeneous neurodevelopmental disorders. METHODS AND PROCEDURE: Navon-type tasks were used to assess visuo-spatial construction ability across 5 groups of children: typically developing, FXS, AFXS, ASD children who scored low-moderate (HFA) and ASD children that scored severe (LFA) on the Childhood Autism Rating Scale (CARS). Analyses of their developmental trajectories compared the performance of these groups. OUTCOMES AND RESULTS: Each group produced their own distinct trajectory. HFA achieved higher scores from an earlier age than the TD group, while the LFA group's performance was driven by a bias in local processing. The FXS performance was normalised by using mental age as a predictor while neither mental nor chronological age predicted the AFXS group performance. CONCLUSIONS AND IMPLICATIONS: The study showed unique processing styles. These findings highlight the importance of taking comorbidity and the severity of symptoms within each condition into account in order to understand cognitive abilities and cognitive profiles.
Research in developmental disabilities, 2017 · doi:10.1016/j.ridd.2017.08.005