Developmental trajectories of hierarchical visuo-spatial processing in fragile X syndrome and ASD: Within- and cross-syndrome variability.
Visual style changes with age, severity, and task, so always assess the child, not the label.
01Research in Context
What this study did
The team tracked how kids solve big-and-small picture puzzles. They used Navon tasks: large shapes made of tiny shapes.
Kids with high-ASD, low-ASD, FXS-only, FXS+ASD, and typical peers each did the puzzles many times. The study mapped how their visual style changed with age.
What they found
Every group followed its own path. Some kids stayed stuck on tiny details. Others quickly saw the whole shape.
Severity mattered more than the diagnosis label. Two children with the same label could use opposite styles.
How this fits with other research
Taylor et al. (2017) ran the same Navon puzzles one year later and got the same pattern. This backs up the finding that trajectories are real and stable.
Scherf et al. (2008) saw no age gain in global shape processing for high-ASD youth. The new data agree: many still focus on small parts years later.
Cardillo et al. (2022) used a different task, the Rey complex figure, and found ASD kids lean on step-by-step memory. Together the papers show the local bias holds across puzzles and tools.
Van Eylen et al. (2018) meta-analysis says task choice changes the size of the local-global gap. The mixed trajectories in Faso et al. (2016) now make sense: the Navon task itself shapes the score.
Why it matters
Do not trust the diagnosis alone to predict visual skills. Test each learner with the actual task you plan to use. If a teen still sees only tiny pieces, break your visual support into small steps first, then teach how to glue them into the whole.
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02At a glance
03Original abstract
BACKGROUND/AIMS: Despite the advances in understanding visuo-spatial processing in developmental disorders such as ASD and fragile X syndrome (FXS), less is known about the profile of those with a comorbid diagnosis, or the role of within-disorder disparities between individuals across the ASD spectrum. METHODS AND PROCEDURES: Using a developmental trajectory approach, we tested 5 groups of children: Typically developing, FXS, FXS+ASD, ASD individuals who had low-moderate symptoms (HFA) and ASD individuals who had severe symptoms (LFA). Symptoms of ASD were assessed using the Childhood Autism Rating Scale: CARS and hierarchical visuo-spatial processing was assessed using the Navon task. OUTCOMES AND RESULTS: Crucially, results differed between HFA and LFA participants. Furthermore, the pattern of results differed between those who had a diagnosis of FXS only and FXS+ASD. Poorer performance within the FXS groups and the group who are low functioning on the ASD spectrum indicated a delayed developmental rate compared to typical controls. CONCLUSIONS AND IMPLICATIONS: This study showed that diagnosis and severity of symptoms are indicative of differences in visuo-spatial processing styles. It is important that heterogeneity within FXS and ASD populations are considered in subsequent studies and look beyond diagnostic group differences.
Research in developmental disabilities, 2016 · doi:10.1016/j.ridd.2015.12.016