音のピッチ記憶と事象関連電位 (ERP)

抄録

Subjects compared the pitches of two test-tones separated by a 2.5-second retention interval. A tone (A tone) of the same pitch as the first test-tone or a tone (B tone) of a little different pitch (+2% or 2%) from that test-tone was interpolated during the interval. B tone elicited N2b component of ERPs, a subcomponent of N200. Since N2b is considered to reflect the controlled processing (Näätänen and Picton, 1986), it is suggested that the storage process of pitch information is associated with the controlled processing.
The recognition performance was more severely affected by B tone compared with A tone. B tone led exclusively the development of CNV on the left temporal area toward the second test-tone. Moreover, ERPs elicited by the test-tone were more negative after B tone than after A tone in a latency range from 300 to 500ms. This diffrences could be attributed to the search-related negativity. We could explain these results that pitch information was rehearsed in a short-term memory when the sensory storage was prevented.