Hierarchical Letters in ASD: High Stimulus Variability Under Different Attentional Modes.

Luckasson et al. (2017) asked 8- to young learners to find tiny letters hidden inside big letters on a screen. Some kids had ASD; some were typically developing.

The task switched between two rules: “look at the big picture” or “look at the small part.” The team measured how much the wrong level slowed the kids down.

Both groups slowed the same amount when the small letter conflicted with the big one. Kids with ASD were not extra distracted by the larger shape.

In plain words, global-local interference did not separate ASD from typical peers.

Pastor-Cerezuela et al. (2020) saw real attention gaps in the same age range. They linked sensory issues to weaker inhibitory control and poorer auditory attention in ASD. Ruth’s clean interference scores seem to clash with those findings, but the tasks differ: Ruth used brief visual patterns; Gemma used school-like listening and memory tests.

Némorin et al. (2025) and Rivard et al. (2023) both show that kids with ASD fall into clear sub-types once you add adaptive or cognitive scores. Ruth’s single visual task did not split the groups, supporting the idea that you need broader batteries to see heterogeneity.

Thulasi et al. (2019) also found no ASD–TD gap on a non-core trait—GI symptoms—when using a tight tool. Together these papers remind us that null results can be real when the measure matches the domain.

If a child with ASD struggles on classroom worksheets with nested graphics, do not blame global-local confusion. Probe sensory needs, executive skills, or motivation instead. Save visual interference tasks for research, not diagnostic reports, and spend your assessment time on tools that capture the sub-types shown by Harmony and Mélina.