Learning sound categories: The role of social information during phoneme learning

Altvater-Mackensen, N. & Grossmann, T.

Max Planck Institute for Human Cognitive and Brain Sciences

Within the first year of life, infants gain profound knowledge about the sound system of their native language. They improve their ability to categorize native sound contrasts (Kuhl et al., 2006) and learn to integrate visual and auditory information about sounds, i.e., to correctly map a heard sound to the mouth gesture associated with its production (Kuhl & Meltzoff, 1982). During this phase of native language attunement, infants seem to actively attend to relevant information sources: they prefer to listen to infant directed speech that provides them with enhanced acoustic cues (Cooper & Aslin, 1990), and they specifically watch a speaker's mouth, which provides them with information about relevant motoric gestures that are associated with sounds (Lewkowicz & Hansen-Tift, 2012). Furthermore, social information seems to play a crucial role in the learning process as infants pick up non-native sound categories during play sessions with a real person, but not when the very same language input is provided via an audio- or video-recording (Kuhl et al., 2003). However, so far research on social influences on early language learning has been relatively limited. The current study therefore addresses the question how the interactive behavior of mother and infant influences phoneme learning. More specifically, we assessed 6-month-old infants' ability to categorize different (native) vowels in a discrimination task and in an audio-visual integration task. In addition, we videotaped the mothers during a free play session with their infants to assess (a) the infant-directedness of mothers' speech, and (b) the joint attention behavior of mother and infant. In this talk, we will present findings concerning the question of whether and how the speech style of the mother and the interactive behavior of both mother and infant predict infants' performance in the language tasks.