Lateralization of speech production starts in sensory cortices--a possible sensory origin of cerebral left dominance for speech.
Speech production is a left-lateralized brain function, which could arise from a left dominance either in speech executive or sensory processes or both. Using functional magnetic resonance imaging in healthy subjects, we show that sensory cortices already lateralize when speaking is intended, while the frontal cortex only lateralizes when speech is acted out. The sequence of lateralization, first temporal then frontal lateralization, suggests that the functional lateralization of the auditory cortex could drive hemispheric specialization for speech production.
Kell
Christian Alexander
CA
Brain Imaging Center and Department of Neurology, Goethe University Frankfurt, 60528 Frankfurt, Germany. c.kell@em.uni-frankfurt.de.
Morillon
Benjamin
B
Kouneiher
Frederique
F
Giraud
Anne-Lise
AL
D000328:Adult; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D013003:Somatosensory Cortex / Q000502:physiology*; D013060:Speech / Q000502:physiology*; D055815:Young Adult