The effect of Infant Directed Speech on face processing in 4-month-old infants.
Sirri, L., Linnert, S., Reid, V., & Parise, E. (2019). The effect of Infant Directed Speech on face processing in 4-month-old infants. Poster presented at the Budapest CEU Conference on Cognitive Development (BCCCD19), Budapest, Hungary.
Newborns and infants prefer faces with direct gaze over faces with averted gaze (Farroni, Csibra, Simion, & Johnson, 2002), and also show an enhanced N290 ERP component to them. One possibil- ity is that direct gaze is an important source of information (Gliga & Csibra, 2007), suggesting that infants are specifically sensitive to communicative signal. (Csibra, 2010). In two ERP experiments we studied whether a different communicative signal, infant-directed speech (IDS), could also enhance face processing in 4-month-olds. In Experiment 1 infants heard a word, uttered either in IDS or adult- direct speech (ADS), followed by an upright face. In Experiment 2 faces were presented upside down. Only upright faces produced a N290 effect depending on the preceding speech, with faces preceded by IDS eliciting a larger N290 component. Such effect was not present with upside down faces. Instead we found a Nc effect, with a larger Nc component for upside down faces preceded by IDS compared to the same stimuli preceded by ADS. These results show that for 4-month-old infants, IDS has a specific effect on face processing, enhancing the early stages of face perception, rather than merely increasing attention to them. We suggest that IDS generates communicative expectations in infants. When such expectations are met by a following stimulus – an upright face – infants are already prepared to process it, hence the N290 effect. When the stimulus is a non-communicative one – an inverted face – IDS increases the allocation of attention to the stimulus, hence the Nc effect.