Investigator: Beverly Ann Goldfield, Rhode Island College

Scientific Theme: Neuroscience

Abstract: The specific aim of this proposal is to examine the lower bounds of verb comprehension using modifications of the Preferential Looking Task (PLT) methodology. The PLT measures word comprehension by comparing visual gaze to two images (target/distracter) displayed on a computer monitor before (baseline trial) and after (test trial) the target image is labeled. Comprehension is defined as an increase in visual attention to the target image during the test trial compared to baseline presentation. We have used the PLT to test verb comprehension in two INBRE-supported studies. In the first study we compared comprehension of 12 nouns (represented by photos of objects) versus 12 verbs (represented by videorecordings of actors performing actions). Children age 16 and 18 months comprehended nouns but not verbs. In the second study we tested comprehension of the same 12 verbs but increased the duration of exposure to the dynamic stimuli during baseline and test trials. Children showed increased attention to the target verb during test compared to baseline presentation, indicating verb comprehension. Moreover, comprehension scores in study 2 were higher than scores in study 1. The is the first laboratory study to report verb comprehension for children as young as 16 months of age. The current proposal extends and further modifies the PLT methodology to test verb comprehension. During SURF 2015 we test comprehension of verbs in children age 12 and 14 months with increased exposure to dynamic stimuli during baseline and test trials. We test the hypothesis that 12 and 14-month-olds comprehend verbs. During SURF 2016 we further modify the PLT for younger children, using a parent-child scenario with a child actor, rather than an adult actor, performing each action. This modification is motivated by research indicating that children’s earliest and most salient exposure to verbs is adult speech that directs child behavior (e.g., sit down, throw the ball to mommy). We use this modified slideshow to test 10-month­ olds; a second group of 10-month-olds view the slideshow with adult actors. We test the hypothesis that 10- month-olds viewing child actors, but not adult actors, comprehend verbs.

Human Health Relevance: Although there is considerable research on language production, we know far less about early comprehension. However, methodologies such as the Preferential Looking Task (PLT) make it possible to examine the earliest stages of word comprehension, which can be used by both researchers and practitioners to predict developmental outcomes for normally developing children and those at risk for language delay.