Summary: A new study shows that toddlers from around two years old can learn new words even when a speaker’s mouth or eyes are covered. Researchers found that successful vocabulary learning is driven by children following the speaker’s gaze and shifting their attention between the speaker and the object, rather than by seeing mouth movements.
These results relieve some concerns about whether face masks might have lasting negative effects on early language development. The findings suggest that encouraging gaze following and active exploration of objects may be more important strategies for supporting early word learning than focusing on visible mouth movements.
Key facts:
- Children aged 24 months and older formed new word–object associations reliably whether the speaker’s full face, eyes (covered by glasses), or mouth (covered by a surgical mask) was visible.
- Stronger word learning was linked to gaze-following behavior and quick alternation of attention between the speaker’s face and the target object.
- Although covering the eyes or mouth changed where infants looked, these changes did not prevent the formation of new word–object links.
Source: UAB
Research teams from the Universitat Autònoma de Barcelona (UAB) and the University of Grenoble Alpes – CNRS examined how visual attention affects early vocabulary learning. Their work indicates that by about two years of age, children can learn new vocabulary after a brief audiovisual interaction even if the speaker’s eyes or mouth are obscured.
Families and childcare professionals raised concerns during the COVID-19 pandemic about whether face coverings might slow language development in toddlers. This study provides reassuring evidence that typical toddlers can still map words to objects even when parts of a speaker’s face are covered.
Published in the journal Developmental Psychology, the study is the first to show that normally developing toddlers can form new word–object associations after a short audiovisual exposure, and that this ability emerges around 24 months of age.
The research highlights the central role of social reference—looking to the speaker for cues—and attentional control during word learning. Rather than relying on visual speech cues from the mouth, toddlers appear to benefit most from coordinated looking behavior that connects the speaker to the object being named.
How attention shapes vocabulary acquisition
Both gaze following (looking where someone else looks) and attention to a speaker’s mouth have been linked in earlier studies to the large increase in vocabulary known as the “vocabulary boost” in the second year of life. Some researchers have proposed that these attention strategies are critical for early lexical development, but causal evidence has been limited.
To test the causal role of visible facial cues, the researchers tracked the eye movements of 153 French children aged 17 to 42 months while they completed a fast-mapping task in three different visual conditions: a fully visible face, eyes obscured by dark glasses, or mouth and nose covered by a surgical mask. During each trial, a speaker repeated a monosyllabic nonsense word several times and shifted gaze to the target object twice.
The results showed that toddlers aged 24 months and older successfully learned the new word–object pairs regardless of whether the speaker’s eyes or mouth were covered. Across ages and conditions, better learning correlated with gaze-following behaviors—specifically, looking at the target object and alternating attention between the speaker’s face and the object—rather than with increased looking at the mouth or eyes.
When parts of the face were covered, children did shift their attention toward uncovered regions, but these shifts did not interfere with their ability to form word–object associations. In the full-face condition, toddlers tended to look at the speaker’s eyes more than the mouth, a pattern that suggests flexible control of visual attention depending on task demands.
Practical strategies to support word learning
Based on these findings, the researchers recommend emphasizing object-focused exploration and encouraging rapid visual shifts between a speaker’s face and the object when teaching new words to toddlers. Such social referencing and active attention to objects appear to be effective supports for early fast mapping.
The authors also acknowledge that attention to the speaker’s mouth may still be important in more demanding listening situations or for children with hearing loss, language disorders, or autism spectrum conditions. They note ongoing work in collaboration with health centers in Grenoble to investigate these populations further.
About this language learning research news
Author: Maria Jesus Delgado
Source: UAB
Contact: Maria Jesus Delgado – UAB
Image: The image is credited to Neuroscience News
Original Research: Closed access. “Covering the eyes or mouth of a speaker does not prevent word learning in typically developing infants” by Joan Birulés et al., Developmental Psychology.
Abstract
Covering the eyes or mouth of a speaker does not prevent word learning in typically developing infants
Gaze-following skills and selective attention to mouths in the first year of life have been correlated with vocabulary growth in the second year. To test whether these attentional strategies are causally necessary for forming word–object associations, the study recorded eye gaze in 153 toddlers aged 17–42 months during an audiovisual fast-mapping task presented under three visual conditions: full face, eyes covered by opaque glasses, or mouth covered by a surgical mask.
Results indicate that the ability to associate a new word form with an object from a brief interaction emerges around 24 months and that successful learning depends on gaze-following and face-to-object attention shifts rather than fixation on the speaker’s eyes or mouth. The findings emphasize the importance of social reference and object exploration in naturalistic vocabulary learning contexts.