Lateralized neonatal EEG coherence during sleep predicts language outcome.

During neonatal NREM sleep, EEG functional connectivity predicts future language development. Left temporal and central EEG coherence-specifically the imaginary component of coherence-is predictive, whereas the same analysis from the right hemisphere is not. These results appear to vary according to the infant's gestational age, and a trend suggests they may be enhanced by measuring functional connectivity during exposure to the mother's voice. These findings identify early evidence of physiologic differentiation within the cerebral hemispheres and raise the possibility that neonatal NREM sleep has a role to play in language development.