Auditory discrimination in infants as revealed by the mismatch negativity of the event-related brain potential

In adults, deviant sounds occurring among repetitive standard sounds elicit the mismatch negativity (MMN) component of auditory event-related brain potential (ERP) even when these sounds are not attended to. MMN appears to be generated in the auditory cortex by a comparison process between deviant auditory input and a neuronal sensory-memory trace that is formed by the repetitive standard stimuli and which represents their physical features. Recent ERP studies have shown that MMN is also elicited in newborns and in older infants by physical changes in simple tones, as well as by changes in phonemes. Thus, MMN might provide a new tool for objective assessment of normal and deficient development of auditory discrimination, sensory memory, and speech perception in infants.