Dorothy V. M. Bishop|Mervyn J. Hardiman|J Barry
Is auditory discrimination mature by middle childhood? A study using time?frequency analysis of mismatch responses from 7 years to adulthood
University of Oxford|University of Oxford|University of Oxford
behavioural electrophysiological studies give differing impressions auditory discrimination mature ability discriminate frequency speech contrasts reaches adult levels around 12 years age yet electrophysiological index auditory discrimination mismatch negativity mmn reported large children adults auditory erps measured 30 children 7 12 years 23 teenagers 13 16 years 32 adults 35 56 years oddball paradigm tone syllable stimuli stimulus type standard stimulus 1000 hz tone syllable ba occurred 70 trials one two deviants 1030 1200 hz tone syllables da bi equiprobably remaining trials traditional mmn interval 100250 ms postonset size mismatch responses increased age whereas opposite trend seen interval 300 550 ms postonset corresponding late discriminative negativity ldn timefrequency analysis single trials revealed mmn resulted phasesynchronization oscillations theta 47 hz range greater synchronization adults children furthermore amount synchronization significantly correlated frequency discrimination threshold results show neurophysiological processes underlying auditory discrimination continue develop childhood adolescence previous reports adultlike mmn amplitudes children may artefactual results using peak measurements comparing groups differ variance