Poster #110 - Retention of word learning from multimodal cues in 13- and 15-month-olds

• In Event: 3-053 - Poster Session 10
  In Poster Session: PS 10 Section - Language, Communication

Integrative Statement

Everyday parent-infant interactions organize infants’ attention and provide structured multimodal information about the environment. Caregivers use exaggerated speech and body movements when interacting with infants (Fernald 1992; Brand, Baldwin, & Ashburn, 2002). In addition, caregivers tend to move objects in synchrony with their speech when teaching their children words (Gogate, Bahrick, & Watson, 2000). In this study we tested the efficacy of these caregiver behaviors for word learning in 13- and 15-month-olds.
We systematically manipulated infant-directed (ID) speech and motion in a novel word learning task. Infants (n=125) were randomly assigned to one of four conditions. Novel objects were labeled using ID or adult-directed (AD) speech. Experimenters either moved the object in synchrony with their speech during labeling or held the object still. During the training phase, experimenters seated across from infants showed infants a novel target object, labeled it with a novel referent (e.g., “dax”), and gave it to infants to play with for 30s. In alternating trials, experimenters showed, labeled and gave infants a novel distracter object. Distracter objects were labeled with matched speech (e.g., “Oh, look at that.”). Object labels were spoken three times per trial (9 instances total). Analysis of experimenter fundamental frequency [F0] during labeling reveals significant differences between AD and ID labeling, but no significant differences between labels paired with motion or no-motion (Table 1).
Immediately after training and again the following day, infants began the test phase. A new female experimenter blind to object-label assignment familiarized infants with putting toys in a basket. After familiarization, the experimenter placed the target and distracter objects in front of infants and asked for the target label. After two trials, objects were replaced with a generalization set matching the original objects in shape and texture, but not color. Infants’ comprehension score was the proportion of correct choices across test and generalization trials.
To test whether infant comprehension was significantly different than would be expected by chance, mean proportion of correct choices were compared to chance performance (.50) in separate one-sample t-tests (Figure 1). For 13-month-olds, only infants trained in the ID-motion condition showed consistent performance at session 1, t(17)=2.40, p<.05, and session 2, t(17)=3.49, p<.01. For 15-month-olds, at session 1, only infants trained in the ID-motion condition showed reliable comprehension performance, t(13)=2.47, p<.05. At session 2, only infants trained in the ID-no motion condition showed reliable comprehension, t(14)=5.17, p<.001.
These results provide direct evidence that infants use ID speech and motion in early word learning, as only 13-month-olds who had experienced both ID speech and motion recalled the correct word-object pairing the next day. Previous research suggests that sleep promotes infant retention of recently encoded language (e.g., an object-referent mapping) and memory reorganization, possibly promoting generalization of previously learned information to new experiences (Gómez, Bootzin, & Nadel 2006; Friedrich et al., 2015). Multimodal labeling trials, followed by sleep, may have allowed infants to actively sustain and organize word memories at 13 months. By 15 months, multimodal information was no longer necessary, though IDS still supported learning.

Authors

• Steven Laine Elmlinger, Cornell University
  Presenting Author

• Jennifer Schwade, Cornell University
  Non-Presenting Author

• Michael Goldstein, Cornell University
  Non-Presenting Author