Manipulation of Physical Contingencies Induces Change in Visual Scanning of Natural Scenes in Infants with ASD Relative to Typically Developing Infants

Background: In recent research involving preferential attention to point-light displays of biological motion, we found that two-year-olds with autism did not orient to social contingencies but attended instead to non-social, physical contingencies that were disregarded by control children. In later studies, we also found that infants with ASD varied their fixation on the faces of others as a function of the physical contingencies embedded therein. In addition, while social context altered preferential viewing patterns in typically developing infants, detection of audiovisual synchrony was not greatly influenced by social context in infants with ASD.

Objectives: The goal of the current project is to investigate what guides visual attention in infants with ASD by inducing changes in their visual scanning of naturalistic social scenes through experimental manipulation of audiovisual synchrony embedded in those scenes, and to quantify those visual scanning patterns as predictors of outcome severity.

Methods: Infants with autism (ASD, N = 15) and typically developing infants (TD, N = 15), ages 12-24 months, watched a 15-minute series of 35 naturalistic clips. These clips were composed of caregivers interacting with an infant, together with a variety of time-varying, moving objects that were dynamically synchronized with the caregiver’s speech. Specifically, we co-varied object rotational motion, rocking motion, and luminance with the amplitude envelope of each utterance, and dynamically varied the degree of synchrony between caregiver and object throughout the movie. Eye-tracking technology was used to track infants’ looking patterns, using the relative fixation time on caregiver and object as our dependent measures.

Results: Results show that, overall, TD infants spend significantly more time fixating on the caregiver’s face compared to the non-social toy while infants with ASD do not show this distinction, fixating equal amounts of time on the two stimuli. With increasing synchrony of the rotational toy, however, we induced changes in the infants’ scanning, guiding their attention more towards the rotational toy and diminishing their attention to the face.  This change in visual scanning occurs more frequently and significantly faster in infants with ASD compared to the TD infants, who take longer to pick up on the synchrony and to attend to the toy. In addition, results show that those infants with ASD who preferentially attend to the toys exhibit more impaired social behavior, as measured by the ADOS Social Affect Score.

Conclusions: Overall, this study suggests that non-social, physical contingencies in a naturalistic setting can be highly distracting to infants with ASD. These findings indicate an early interruption of typical social experience and suggest one mechanism by which infants with ASD may fail to attend to important social cues in their environment.  Furthermore, by measuring individual sensitivity to non-social contingencies, and inducing changes in visual scanning behavior, we may learn how to develop effective early interventions for infants with ASD by either minimizing the impact of distracting environmental cues, or by using cues that may be innately attention-getting to infants with ASD to foster socially relevant learning.