Odd-ball paradigm.

Odd-ball stimulus pairings used to elicit the auditory mismatch response to assimilation of nasal segments in different phonemic contexts. Mismatch always concerned a change in a single place feature of the nasal, frequent (n→m) and infrequent (m→n), embedded in a context that either promoted the change or not. The identity mismatch (iMMN) was computed by subtracting the evoked response to each pseudoword presented as standard from the response to the same stimulus presented as deviant. The iMMN conditions were defined on the basis of deviants at the time of data acquisition.