This book establishes a dialog between experimental psychology and electrophysiology in the study of infant language development. On the one hand, traditional methods of investigation into language development have reached a high level of refinement despite being confined to observing infants’ overt behavioral responses. On the other hand, more recent methods such as neuroimaging and, in particular, event-related potentials provide access to implicit responses from the infant brain while often relying on rather gross experimental contrasts. The aims of this book are both to provide neuroscientists with an overview of the ingenious behavioral paradigms that have been developed in the field of language development and to introduce the power of neurophysiological indices to behavioral experimentalists. The two approaches are compared at various levels of processing: phonetic discrimination, categorical perception, speech segmentation, syllable and word recognition, semantic priming. A general discussion brings together the two approaches, highlights their respective contributions and limitations and proposes constructive ideas for future integration.