Human language evolved from combinations of syllables and hand gestures, as suggested by a study by the École Normale Supérieure de Paris (France) published in the journal Proceedings of the National Academy of Sciences (PNAS). The study links left-hemisphere-dominated language processing with the use of both hands.
The scientists, led by Anne-Lise Giraud, used electroencephalography (EEG) and functional magnetic resonance imaging to analyze brain activity in 16 subjects while they were resting or watching a video. In both situations, brain areas associated with syllabic hearing, basic sensory processing, and hand and mouth movements showed characteristic activity patterns of left-brain-dominated language . The results suggest that these areas are asymmetrically organized and could form the basis for left-brain-dominated language in modern humans.
The findings also suggest that the brain is organized to produce syllabic language, but that phonemes, the smallest sounds that make up language contrasts with meaning, are acquired, a hypothesis consistent with language development in hearing and deaf infants. .
