The geometric preference subtype in ASD: identifying a consistent, early-emerging phenomenon through eye tracking

Area of Science:

• Neuroscience
• Developmental Psychology
• Clinical Psychology

Background:

• Autism spectrum disorder (ASD) presents significant phenotypic heterogeneity, necessitating tools to identify distinct subtypes.
• Previous eye-tracking studies identified an ASD subgroup preferring geometric over social stimuli, correlating with greater symptom severity.
• This study investigates if this preference generalizes across varying social stimuli complexity.

Purpose of the Study:

• To validate the 'GeoPref test' using complex social stimuli for identifying ASD subtypes.
• To assess the diagnostic utility of the 'Complex Social GeoPref test' in detecting ASD.
• To explore the correlation between visual attention patterns and ASD symptom severity.

Main Methods:

• Two hundred and twenty-seven toddlers (76 with ASD) viewed dynamic geometric and social images.
• Eye-tracking measured visual fixation time and saccades.
• Cognitive and social functioning were assessed using MSEL, ADOS, and VABS.

Main Results:

• ASD toddlers showed a significant preference for geometric images compared to other groups.
• A correlation was found between fixation patterns in both original and Complex Social GeoPref tests, confirming a meaningful ASD subgroup.
• The combined GeoPref tests identified 35% of ASD toddlers as "GeoPref" subtype (94% specificity, AUC 0.75).

Conclusions:

• Eye tracking accurately identifies a specific ASD "GeoPref" subtype with elevated symptom severity, irrespective of social image complexity.
• The GeoPref tests demonstrate predictive value for ASD at the individual level.
• These findings support the potential clinical applications of GeoPref tests for early identification, prognosis, and tailored treatments in ASD.