Infants' individual sensitivity to saliency shapes early word learning in social interaction

In this paper, we conducted an extended analysis of an existing eye-tracking study (Wildt, 2023) investigating how infants' individual sensitivity to saliency shapes early word learning in social interaction. In a first phase of the study, 10-month-old infants participated in a saliency test for their attention. We used existing baseline data but applied a new analysis approach to model infants' attentional profiles-high and low preference group for salient stimuli. Afterwards, infants were exposed to the label of the referent and then participated in one of the two conditions of exploring it: In solo exploration condition (SE), infants were given the object to explore by their own; in the joint exploration condition (JE), infants could explore the object and its goal with the experimenter. In our new analysis of the test phase, we examined how differences in the sensitivity to the saliency influence infants' word learning based on the type of social interaction they receive. Our findings show that infants' looking behavior differed between JE and SE condition, with greater increases in target-directed looks over time in the JE condition. Moreover, only infants with low-preference for saliency in the JE condition successfully retrieved word-object links in all test trials. These results suggest that while joint actions can support attentional control, only infants with more balanced attention control benefit from joint actions in word learning. We conclude that early word learning is shaped by the sensitivity to the saliency in the environment, whereas social interaction helps infants to overcome the saliency bias.