Ghislaine Dehaene-Lambertz, November 15
Nature and Nurture in language acquisition: Anatomical and functional brain-imaging studies in infants
INSERM U992, Neurospin/CEA, Saclay, France
In adults, speech processing relies on precise and specialized networks, located primarily in the left hemisphere. Contrary to the classical hypothesis of an initial equipotential brain, we observe strong asymmetries in the infant brain both at a structural level and at a functional level, equivalent to what is described in adults.
Furthermore, from the first weeks of life on, brain activity is not limited to sensory regions but involves high-level associative areas, such as frontal and parietal areas, suggesting that infants are more actors than passive receptors in learning. More specifically concerning language learning, the results obtained with functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) show that the neuronal networks engaged when infants listen to speech are close to those described in adults and comprise multiple brain areas that are involved in phonological representations, lexical storing, attention, short-term and long-term memory in adults. These similarities between preverbal infants and adults expert in their native language, suggest a continuity in functional and anatomical structures that underlie language processing. We observed also strong involvements of the attentional and emotional networks when infants are listening to speech, especially to their mother’s voice. This suggests that language learning might be favored by top-down effects, especially coming from frontal areas, enhancing linguistic processing. Understanding early cerebral development is one of the most promising and stimulating challenge of the last years and cerebral imaging provides new insights on infant cerebral resources to process the external world.
- Where and when:
15:30-17:00 Nov 15, 2012MPI Nijmegen, Rm 163