Electrophysiological evidence of developmental changes in the duration of auditory sensory memory

In behavioral studies, children's memory for tonal frequency has been found to persist for less time than adults' (T. A. Keller & N. Cowan, 1994). The present study was done to evaluate the argument that this effect is due to changes in auditory sensory memory and not to attentional mechanisms. This question was investigated using mismatch negativity (MMN), an auditory event-related potential considered to be insensitive to attention. Participants were 6-7-, 8-10-, and Il-la-year-old children and adults. They were presented with trains of stimuli, beginning with either a standard (1000 Hz) or a deviant (1200 Hz) tone with trains separated by either 1 s or 8 s. All 4 groups exhibited MMNs after delays of I s, but only the adults and oldest children exhibited MMNs after 8 s, indicating that there are maturational changes in the duration of auditory sensory memory.