Characteristics of infant-directed speech in caregivers with traumatic experiences

One of the factors underlying maternal depression is the exposure to traumatic experiences that reduces the thresholds for developing depressive symptoms. Research suggests that depressed mothers produce a lower pitch, less expanded pitch range, a lower mean length of utterance in morphemes (MLU) and respond slower to infants compared to non-depressed mothers. Are the characteristics of infant-directed speech (IDS) affected by traumatic experiences in caregivers? The study examined the characteristics of IDS in two groups of mothers: those exposed to traumatic experiences (N=2) and those not exposed (N=6). The MLU, mean pitch, pitch range, and utterance duration were measured in maternal speech to infants and to an adult experimenter. This study demonstrated that the higher the maternal traumatic experiences were and the older the infant was, the less expanded F0 range was in ID compared to adult-directed speech. There was no effect of maternal traumatic experiences, maternal depression, and child age on F0 mean, MLU, and utterance duration. These results suggest that maternal traumatic experiences affect some prosodic characteristics of IDS. The results of the study contribute to our understanding of how traumatic experiences in caregivers affect linguistic development in children.