Changes of the Mismatch Negativity (MMN) component of ERPs elicited by sub-and suprasegmental speech contrasts were investigated in adults, school children of developmental language deficit and in infants.
The MMN to different acoustic cues, phonetic contrast and word stress, both playing an important role in language comprehension was investigated. Voice onset time (VOT) and stress pattern changes of bisyllabic Hungarian words were used in passive oddball paradigm.
Our results show that the MMN latency is time locked both to the stressed and to the unstressed syllables though occurs with larger amplitude to the second syllable changed from unstressed to stressed. The MMN to the violated first syllable occured somewhat later than that to the VOT contrast both in adults and normally developing school-children. Moreover, both types of the MMN could be recorded in all 3-10 months old infants including preterm infants but the low birth weight pathological ones.
Our MMN data acquired in children of developmental language deficit (SLI)have proven the assumptions that both sub- and suprasegmental cues are abnormally processed in this particular group of children.