Links between looking and speaking in autism and first-degree relatives: insights into the expression of genetic liability to autism

Abstract

Background: Rapid automatized naming (RAN; naming of familiar items presented in an array) is a task that taps fundamental neurocognitive processes that are affected in a number of complex psychiatric conditions. Deficits in RAN have been repeatedly observed in autism spectrum disorder (ASD), and also among first-degree relatives, suggesting that RAN may tap features that index genetic liability to ASD. This study used eye tracking to examine neurocognitive mechanisms related to RAN performance in ASD and first-degree relatives, and investigated links to broader language and clinical-behavioral features.

Methods: Fifty-one individuals with ASD, biological parents of individuals with ASD (n = 133), and respective control groups (n = 45 ASD controls; 58 parent controls) completed RAN on an eye tracker. Variables included naming time, frequency of errors, and measures of eye movement during RAN (eye-voice span, number of fixations and refixations).

Results: Both the ASD and parent-ASD groups showed slower naming times, more errors, and atypical eye-movement patterns (e.g., increased fixations and refixations), relative to controls, with differences persisting after accounting for spousal resemblance. RAN ability and associated eye movement patterns were correlated with increased social-communicative impairment and increased repetitive behaviors in ASD. Longer RAN times and greater refixations in the parent-ASD group were driven by the subgroup who showed clinical-behavioral features of the broad autism phenotype (BAP). Finally, parent-child dyad correlations revealed associations between naming time and refixations in parents with the BAP and increased repetitive behaviors in their child with ASD.

Conclusions: Differences in RAN performance and associated eye movement patterns detected in ASD and in parents, and links to broader social-communicative abilities, clinical features, and parent-child associations, suggest that RAN-related abilities might constitute genetically meaningful neurocognitive markers that can help bridge connections between underlying biology and ASD symptomatology.

Keywords: Autism spectrum disorder; Broad autism phenotype; Endophenotype; Eye movement; Eye-voice span; Gaze; Language; Rapid automatized naming; Restricted and repetitive behaviors; Social communication.

Fig. 1

Figures display naming time and error rate in the ASD vs. control groups on the left panel, and parent-ASD group vs. parent-controls on the right panel

Fig. 2

Figures display eye-voice span, total fixations, and refixations in the ASD vs. control groups on the left panel, and parent-ASD group vs. parent-controls on the right panel

Fig. 3

Clinical-behavioral correlates of RAN ability. a Longer RAN naming time was associated with lower narrative ability among individuals with ASD. b Longer RAN naming time was correlated with increased severity of restricted and repetitive behaviors in ASD

Fig. 4

Parent-child correlations in families of individuals with ASD. Greater rates of visual regressions in BAP(+) parents only (mothers and fathers) were associated with increased severity of restricted and repetitive behaviors in their children with ASD. This pattern was not observed for BAP(−) parents