Associative learning processes underlie infants' understanding of contingencies during social interactions and may serve as a building block for the development of adaptive social behavior. Contingent social interaction is a key element in the development of adaptive social behaviors and learning of contingencies can be observed within the first months of life. Specifically, human infants learn to associate complex multisensory cues, such as faces, voices, and odors, with particular social meaning, enabling the expression of socially appropriate behavioral responses in complex contexts. However, although the development of social behavior in infancy has been well described, there still remains significant knowledge gaps in our understanding about the underlying mechanisms involved in the associative learning processes that give rise to these behaviors. For example, newborn infants are capable of associative learning and accomplish a good deal of their learning within a social context, yet whether social contexts modulate the efficacy of early learning and memory processes and associated neurobiology is not well understood. Recently, we have demonstrated that social cues (i.e., woman's voice) facilitate learning acquisition in one-month-old infants suggesting that ecologically- relevant social cues influences young infants learning processes, specifically leading to enhancement in the rate of learning. The proposed experiment will expand upon these initial results to further examine infants' long-term retention (i.e., memory) of the learned response and whether retention of the learned response is also modulated by social cues. In addition, by simultaneously recording infants' electrical brain activity during both learning acquisition and retention, we will be able to examine neural correlates associated with learning and memory processes and the modulatory effect of social cues on these neural responses. We hypothesize that infants conditioned with social cues will display faster learning acquisition, greater retention of the conditioned response, and enhanced neural signatures of memory compared to infants conditioned to a social control cue (i.e., backward voice). Understanding more about the role of social context on learning and memory processes during early infancy may be useful in developing biomarkers for neurodevelopmental disorders, particularly those associated with social deficits such as autism spectrum disorder and Fragile X.
