An Eye-Tracking Study of Receptive Verb Knowledge in Toddlers

Abstract

Purpose We examined receptive verb knowledge in 22- to 24-month-old toddlers with a dynamic video eye-tracking test. The primary goal of the study was to examine the utility of eye-gaze measures that are commonly used to study noun knowledge for studying verb knowledge. Method Forty typically developing toddlers participated. They viewed 2 videos side by side (e.g., girl clapping, same girl stretching) and were asked to find one of them (e.g., “Where is she clapping?”). Their eye-gaze, recorded by a Tobii T60XL eye-tracking system, was analyzed as a measure of their knowledge of the verb meanings. Noun trials were included as controls. We examined correlations between eye-gaze measures and score on the MacArthur–Bates Communicative Development Inventories (CDI; Fenson et al., 1994), a standard parent report measure of expressive vocabulary to see how well various eye-gaze measures predicted CDI score. Results A common measure of knowledge—a 15% increase in looking time to the target video from a baseline phase to the test phase—did correlate with CDI score but operationalized differently for verbs than for nouns. A 2nd common measure, latency of 1st look to the target, correlated with CDI score for nouns, as in previous work, but did not for verbs. A 3rd measure, fixation density, correlated for both nouns and verbs, although the correlation went in different directions. Conclusions The dynamic nature of videos depicting verb knowledge results in differences in eye-gaze as compared to static images depicting nouns. An eye-tracking assessment of verb knowledge is worthwhile to develop. However, the particular dependent measures used may be different than those used for static images and nouns.

Lexical Processing of Nouns and Verbs at 36 Months of Age Predicts Concurrent and Later Vocabulary and School Readiness

“…We know less about how eye gaze measures of lexical processing with dynamic scenes are related to outcomes. A handful of studies have used dynamic scenes to depict verb referents in eye-tracking tasks with young children (Bergelson & Swingley, 2013;Goldfield, Gencarella, & Fornari, 2016;Golinkoff et al, 1987;Horvath, 2019;Horvath & Arunachalam, in preparation;Huttenlocher, Smiley, & Charney, 1983;Naigles, 1997;Naigles & Hoff, 2006;Valleau et al, 2018). Related to the current study, Goldfield et al (2016) found that eye gaze measures of verb knowledge correlated with PPVT scores in children ages 3 to 5 years (they did not examine lexical processing speed specifically).…”

“…Related to the current study, Goldfield et al (2016) found that eye gaze measures of verb knowledge correlated with PPVT scores in children ages 3 to 5 years (they did not examine lexical processing speed specifically). In contrast, Valleau et al (2018) found that lexical processing speed for verbs did not correlate with expressive vocabulary for 22-to 23-month-olds -though it did for nouns, just as in prior work (e.g., Fernald et al, 2006). However, in a study of older children with autism spectrum disorder in the same paradigm as Valleau et al (2018), latency did correlate with vocabulary for both nouns and verbs (Horvath, 2019;Horvath & Arunachalam, in preparation).…”

“…In contrast, Valleau et al (2018) found that lexical processing speed for verbs did not correlate with expressive vocabulary for 22-to 23-month-olds -though it did for nouns, just as in prior work (e.g., Fernald et al, 2006). However, in a study of older children with autism spectrum disorder in the same paradigm as Valleau et al (2018), latency did correlate with vocabulary for both nouns and verbs (Horvath, 2019;Horvath & Arunachalam, in preparation). Clearly, more evidence is needed.…”

“…However, a methodological caveat calls this hypothesis into question. While prior work testing noun referents in lexical processing tasks has almost exclusively used static images to depict those referents, most verb referents are best depicted using dynamic action scenes in which participants can view the referent event unfold over time (e.g., Konishi, Stahl, Golinkoff, & Hirsh-Pasek, 2016;Valleau, Konishi, Golinkoff, Hirsh-Pasek, & Arunachalam, 2018). We know less about how eye gaze measures of lexical processing with dynamic scenes are related to outcomes.…”

“…To examine lexical processing, we used a variant of Fernald et al's (1998) lexical processing task. In addition to including verb trials as well as noun trials, one additional difference also shared by Valleau et al (2018) (and Goldfield et al, 2016, although their paradigm differs from the current paradigm in several other ways) bears mention: while the standard paradigm presents an auditory label while the two test images are on the screen, in our paradigm the images are replaced with a centrally positioned fixation star as the test prompt is heard and then the images reappear. This design has two advantages.…”