Eye Tracking as a Measure of Receptive Vocabulary in Children with Autism Spectrum Disorders

Abstract

This study examined the utility of eye tracking research technology to measure speech comprehension in 14 young boys with autism spectrum disorders (ASD) and 15 developmentally matched boys with typical development. Using eye tracking research technology, children were tested on individualized sets of known and unknown words, identified based on their performance on the Peabody Picture Vocabulary Test. Children in both groups spent a significantly longer amount of time looking at the target picture when previous testing indicated the word was known (known condition). Children with ASD spent similar amounts of time looking at the target and non-target pictures when previous testing indicated the word was unknown (unknown condition). However, children with typical development looked longer at the target pictures in the unknown condition as well, potentially suggesting emergent vocabulary knowledge.

An Open Conversation on Using Eye-Gaze Methods in Studies of Neurodevelopmental Disorders

“…Because eye-gaze methods require only passive engagement-namely, sitting and looking at a screen-they have limited behavioral demands relative to assessment techniques that require a purposeful response (Abbeduto, Kover, & McDuffie, 2012;Falck-Ytter, Bölte, & Gredebäck, 2013;Karatekin, 2007). This means that eyegaze methods may be well suited for children with NDD who are unable to follow an examiner's overt requests or are distressed by them (Brady, Anderson, Hahn, Obermeier, & Kapa, 2014;Charman, Drew, Baird, & Baird, 2003). Factors such as social engagement or motor planning can affect the content validity of some examiner-directed tasks, but, depending on the experimental design, eye-gaze methods may lessen these effects and/or quantify their impact on processing and learning.…”

“…Having infants and toddlers sit on the lap of a parent or caregiver often places children at an appropriate height to view the screen, and the presence of a familiar adult provides reassurance. Other studies use booster seats with straps to minimize movement and adapt for differences in body size (e.g., Brady et al, 2014). Because automatic eye trackers require participants to be seated within a relatively restricted three-dimensional space, it is important to allow adjustment for participants of variable heights (Sasson & Elison, 2012).…”

“…Because automatic eye trackers require participants to be seated within a relatively restricted three-dimensional space, it is important to allow adjustment for participants of variable heights (Sasson & Elison, 2012). This flexibility can be achieved by changing the height of the eye tracker (e.g., with a movable wall mount) and/or the height of the chair (e.g., with a hydraulic chair; Brady et al, 2014). When a child sits independently in a chair to complete an eye-gaze task, an informed adult should be present in the testing booth for safety.…”

“…Increased temporal resolution may be valuable if the planned analyses will take advantage of the number of samples provided. However, gaze patterns are often averaged and analyzed over longer spans of time, in which case the potential advantage of high temporal resolution is lost (Brady et al, 2014;Naigles, Kelty, Jaffery, & Fein, 2011;Venker, Eernisse, Saffran, & Ellis Weismer, 2013). Growth curve analyses that examine gaze patterns over time may take advantage of higher temporal resolution (see "Time Course Analysis"), but even researchers using this approach may aggregate eye-tracking data over longer time windows (e.g., 50 ms) to account for eye movement-based dependencies (Barr, 2008) and to reduce the sheer volume of data.…”

Integrating Orthographic and Phonological Knowledge in Early Readers: Implicit and Explicit Knowledge

“…We track their gaze during this task to determine where they focus when they make their decision. Previous uses of eye-tracking technology have suggested that children's attention to stimuli may indicate an implicit understanding (e.g., [45,46]). In addition to the general effect of focus on phonology on orthographic knowledge we expect different levels of response for different orthographic combinations.…”