Both heard speech and observed action-sequences consist of continuous streams of to-be- processed information. Boundaries in the signal help the listener/observer to segment or chunk the incoming information into meaningful units. In speech, intonation-phrase boundaries, which usually coincide with syntactic boundaries, are characterized by prosodic boundary cues, such as pre-boundary pitch changes, pre-boundary lengthening, and pause. The processing of those cues is an important prerequisite of language acquisition, and is accordingly found already in the first year of life. In action sequences, pauses are also relevant to identify action units, and respective processing has been shown for 11-month-old infants.
Action segmentation can also rely on other kinematic cues, such as time intervals with high limb acceleration/deceleration and high motion velocity, but the processing of such has only scarcely been studied in infants. Besides these signal-driven bottom-up cues, adults also apply top-down knowledge to segment continuous streams of information (in the linguistic domain: lexical and syntactic knowledge; in the action domain: conceptual knowledge about the structure and functionality of actions). In the action domain, such knowledge-based segmentation has been proposed already for 11-month-olds. It is so far unknown how bottom-up and top-down mechanisms interact in infants’ and young children’ segmentation of speech or action, and to what extend their operation is domain-general. Using series of EEG- and eye-tracking investigations in young infants and children (from 6 to 42 months of age), our interdisciplinary project aims to characterize commonalities and/or differences in segmentation or chunking processes in speech perception and action observation.
We will mainly focus on the roles of signal-based bottom-up processes and of knowledge-based top-down processes in the early development of segmentation abilities in the two domains. In addition, we will characterize the neurocognitive basis of the development of speech and action segmentation, which will further inform about the domain-generality or -specificity of the involved cognitive processes. Furthermore, we will gain a better knowledge on how the interplay of bottom-up and top-down processes in segmentation is related to the early development of general cognitive competences. In sum, the planned research will contribute to a more detailed understanding of the interplay of language, cognition, and the brain in young children’s segmentation of continuous streams of linguistic and non-linguistic information.