Scientific article
Open access

Neurophysiological origin of human brain asymmetry for speech and language

Publication date2010

The physiological basis of human cerebral asymmetry for language remains mysterious. We have used simultaneous physiological and anatomical measurements to investigate the issue. Concentrating on neural oscillatory activity in speech-specific frequency bands and exploring interactions between gestural (motor) and auditory-evoked activity, we find, in the absence of language-related processing, that left auditory, somatosensory, articulatory motor, and inferior parietal cortices show specific, lateralized, speech-related physiological properties. With the addition of ecologically valid audiovisual stimulation, activity in auditory cortex synchronizes with left-dominant input from the motor cortex at frequencies corresponding to syllabic, but not phonemic, speech rhythms. Our results support theories of language lateralization that posit a major role for intrinsic, hardwired perceptuomotor processing in syllabic parsing and are compatible both with the evolutionary view that speech arose from a combination of syllable-sized vocalizations and meaningful hand gestures and with developmental observations suggesting phonemic analysis is a developmentally acquired process.

  • Adult
  • Auditory Cortex/physiology
  • Brain/anatomy & histology/physiology
  • Dominance, Cerebral/physiology
  • Electroencephalography
  • Humans
  • Language
  • Magnetic Resonance Imaging
  • Male
  • Motor Cortex/physiology
  • Speech/physiology
  • Young Adult
Affiliation Not a UNIGE publication
Citation (ISO format)
MORILLON, Benjamin et al. Neurophysiological origin of human brain asymmetry for speech and language. In: Proceedings of the National Academy of Sciences of the United States of America, 2010, vol. 107, n° 43, p. 18688–18693. doi: 10.1073/pnas.1007189107
Main files (1)
Article (Published version)
ISSN of the journal0027-8424

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