Year ReviewNancy Rader

May 13, 2011

esearchEmotion and Working MemoryTemperamentInfant PerceptionAttention and Early Language

yeTracking: A Window into the Mind of a Child

NFANT RESEARCHGetting Their Attention through Gesture

The ProblemHow do young infants discover that a segment of the sound stream references a particular aspect of the visual world around them?

Joint Attentionaccomplished through

Gaze FollowingPoint Following

But these are not reliably available before 15 months of age

Mother Introducing Object Name to Infant

3-D Motion Analysis of Gesture

Sahlstrom, A., Rader, N., & King, D. (2009). Measuring speech-gesture synchrony in mother-to-infant interactions. Presented at the biennial meeting of the Society for Research in Child Development, Denver, CO.

borky

Tennessee… Tennessee… Look at the Borky…

Digital video technology was used to create the video segments for the two conditions so that they were identical except for the gesture.

Studying the Effects of Gesture on Early Word Learning in Infants 9-14 Months of Age*

Rader, N. & Zukow-Goldring, P. (2011, in press). Caregivers’ Gestures Direct Infant Attention during Early Word Learning: The Importance of Dynamic Synchrony. Language Sciences,33(4).

*Research supported by a grant from NSF

Method

Participants• From English-speaking homes in the Ithaca NY area• Criterion for participation: Able to look at “mommy” when asked

– Study 1 17 infants aged 9.8-13.9 months (M=11.9)– Study 2 15 infants aged 9.6-14.7 months (M=12.5)

Design • Within-subject design • Independent Variable: Type of gesture

– Study 1 synchronous dynamic vs. static– Study 2 synchronous dynamic vs. asynchronous dynamic

Hypotheses of Research

Study 2Infants will pay more attention to an object at the time a word is said if the dynamic gesture is made in synchrony with the saying of the word, as compared with an asynchronous dynamic gesture. Use of the synchronous, dynamic gesture to direct attention will result in better word learning.

Study 1Infants will pay more attention to an object at the time a word is said if a synchronous dynamic gesture, as compared with a static gesture, is used to highlight the object in coordination with the saying of the word. This directing of attention through a dynamic gesture will result in better word learning.

Apparatus• 42” plasma screen for presentation of videos• Car seat for infant • Eye tracking hardware and software from Applied Science Laboratory• Computational software from Eye Response Technology• Sensor above the right eye to track head movements. • Teletubbie video clip was presented while the infant’s eye was captured by the eye tracking system.

Data Analysis• Look Zones for Learning Trials

Study 1Gaze Duration for Object during NamingInfants’ gaze durations for the object while it was being named were significantly longer in the dynamic condition (M=2.01, SD=1.60) than in the static condition (M=.47, SD=.59), t(16)=4.283, p<.001, n2=.53.

Study 1: Other Gaze Duration Data

• Infants looked at the object significantly more when it was paired with a dynamic gesture (M=7.08, SD=3.44) than a static gesture (M=2.09, SD=1.89), t(16)=5.228, p<.001, n2=.63.

• Infants’ total amount of time spent looking at the screen in the synchronous dynamic condition was not significantly different (M=16.28, SD=5.21) from the static condition (M=16.47, SD=6.02).

Study 2Gaze Duration for the Object during NamingInfants’ total time looking at the object during the word was significantly longer in the synchronous condition (M=1.76, SD=1.17) than in the asynchronous condition (M=1.11, SD=1.02), t(14)=1.915, p=.038, n2=.23

• Infants’ total amount of time spent looking at the screen was not significantly different in the synchronous condition (M=19.01, SD=5.08) when compared to the asynchronous condition (M=19.95. SD=5.95)

• Infants’ total amount of time spent looking at the object was not significantly different in the synchronous condition (M=6.98, SD=3.54) when compared to the asynchronous condition (M= 6.97, SD=3.89)

Other Gaze Duration Data

So, while movement directs attention toward the object, as seen in Study 1, it is the synchrony that directs looking at the object at the critical time for binding the sound of the word together with the sight of the object.

Test for Word Learning

Example of Looking during Test of Word Learning

Measure: After each request, the number of looks to each object was counted. The Dependent Measure for word learning was the ratio of total correct looks to total looks.

Study 1: Word Learning Results

• There was a significant difference between the two conditions as shown by an ANCOVA with age as the covariate, F(1,15)=10.631,p=.003

• Younger infants benefited more than older infants from the dynamic gesture

• Infants 12.5 or younger showed better word learning when exposed to the dynamic condition (M=.64, SD=.27) than the static condition (M=.36, SD=.33), t(9)=2.083, p=.034, n2=.16.

Study 2: Word Learning Results

A paired samples t-test between the synchronous and asynchronous condition showed significantly better word learning for the synchronous condition (M=.68, SD=.21) over the asynchronous condition (M=.44, SD=.27), t(14)=2.71, p=.01.

Attention to the Speaker’s Mouth

The Importance of Watching the Mouth for Early Language

Motor Neurons?

Developmental Task = learning motor control to produce English phonemes

Mean Ratio of Gaze Duration for the Speaker’s Eyes compared to the Gaze Duration for the Mouth = .286 (SD = .32)

In other words, infants 9 – 14 months of age spent nearly 4 times as much time looking at the speaker’s mouth compared to the time spent looking at the speaker’s eyes.

Rader, N. & Zukow-Goldring, P. (2010). How the hands control attention during early word learning. Gesture, 10:2-3, 202-221.

Next research question

Does this attention to the mouth change with development?

i.e., is there a developmental shift from looking at the mouth to looking at the eyes?

We hypothesized that there should be given• the necessity of looking at the speaker’s eyes

for gaze following• the emotional information provided by the

eyes

Preschool StudyParticipants Twenty typically developing children (10 males and 10 females) ranging in age from 19 to 49 months (M = 32.14, SD = 10.49) participated in the studyFourteen typically developing infants (7 males and 7 females) ranging in age from 9 to 15 months (M= 12.01, SD= 1.54)

The procedure of our current study was the same as that of the previous infant study except:• We used a different physical set-up to accommodate the size of the older

children• Eye fixations were measured using a system provided by the Mangold

Corporation

Rader, N., Zukow-Goldring, P., Stuprich, E., & Rhoades, M. (April, 2011). Looking away from the speaker’s mouth: A developmental shift from infancy to preschool. Presented at the biennial meeting of the Society for Research in Child Development, Montreal, Canada.

Hypothesis: While infants spent more time looking at the speaker’s mouth than at her eyes, preschoolers will spend more time looking at the speaker’s eyes than at her mouth.

Results: For the preschoolers, the mean ratio of gaze duration for the eyes to the mouth was 3.60 (SD = 4.96), while for the infants it was .286 (SD = .325); this difference was significant, t(32) = 2.485, p = .018.

AGE

Current Eye Tracking Research

1. Filling in the developmental gap – testing infants 15-19 months of age

2. Doing longitudinal research with infants beginning at 4 months of age

3. Testing atypically developing children, e.g., those with a diagnosis of ASD

Many thanks to Research Team 04!!

Spring 2011