Poster #52 - Does Infant Gaze While Babbling Change Parental Perception of Vocal Maturity?

• In Event: Poster Session 06

Abstract

Framework: Perception of information is often impacted by integration of multi-modal sensory input (e.g., the McGurk effect), but this lens is infrequently considered in relation to parental responses to infant behaviors. In this preregistered study (osf.io/d7yg5), we ask how infants’ gaze when babbling impacts caregivers’ perception of infant vocalizations.

Background: Caregiver responses to infant babbling are important for real-time learning of information. Infants show facilitated learning of contingent information (responses provided promptly within 2-seconds of their vocalizations) compared to information that is provided non-contingently (Goldstein & Schwade, 2008; Goldstein et al., 2010). Recent work investigating the social functions of babbling found that the infants’ own vocal properties shape mothers’ contingent response patterns. When asked to rate infant vocalizations using the acoustic properties alone, mothers show a stepwise pattern in their rating of infant vocal maturity on a 7-point speech maturity scale (Albert et al., 2018). Canonical syllables are perceived as the most speech-like, while quasi-resonant vowels are perceived as less speech-like. Mothers then use their perception of vocal maturity when deciding whether or not to respond promptly to infant vocalizations. For example, vocalizations that are perceived as least speech-like (e.g., quasi-resonant vowels) are most likely to be ignored. Further, vocal quality impacts the type of information mothers’ respond with following a babble. Canonical syllables are more likely to be imitated than other vocal types. Infant gaze while babbling also impacted responding. Regardless of vocal quality, vocalizations directed at objects are more likely to receive a response than vocalizations that are undirected (i.e., the infant is not looking at an object or a caregiver). These findings led us to ask whether infant visual gaze interacts with the vocal quality to influence caregivers’ perception of vocal quality.

Methodology: 40 Mothers (20 primiparous and 20 multiparous) of infants between 9-12 months of age will be recruited to participate in an online experiment. Participants will watch 80 test stimuli clips of infants at play manipulated for infant gaze and vocal quality (stimuli from Albert et al., 2018). Participants will be asked to rate each vocalization on an ordinal 7-point speech maturity scale, defined as how speech-like the vocalization was (1 = least speech-like, 7 = most speech-like). A 2 (infant gaze: object-directed, undirected) x 4 vocal quality (canonical syllable, marginal syllable, fully resonant, quasi resonant) repeated measures ANOVA will compare participants speech ratings. We expect to first replicate the main effect of vocal quality found by Albert and colleagues (2018). We also hypothesize a directedness x vocal quality interaction where vocalizations containing consonants, but not vowels will be perceived as more speech-like when directed at objects.

Implications: If our hypotheses are supported, these results would demonstrate that infant gaze moderates judgements of infant vocal quality, providing a mechanistic explanation for why caregivers show stronger reactions to particular infant vocalizations. These findings also have implications for infant learning as we know that caregivers respond more strongly to certain types of vocalizations which may change infants’ opportunities for learning based on the types of vocalizations produced.

Authors

• Melissa Geary, Lebanon Valley College
  Presenting Author

• Rachel R Albert, Lebanon Valley College