Fujioka Takako, Trainor Laurel J, Ross Bernhard
Rotman Research Institute, Baycrest, University of Toronto, Canada.
Neuroreport. 2008 Feb 12;19(3):361-6. doi: 10.1097/WNR.0b013e3282f51d91.
This study examined whether two simultaneous pitches have separate memory representations or an integrated representation in preattentive auditory memory. Mismatch negativity fields were examined when a pitch change occurred in either the higher-pitched or the lower-pitched tone at 25% probability each, thus making the total deviation rate of the two-tone dyad 50%. Clear MMNm was obtained for deviants in both tones confirming separate memory traces for concurrent tones. At the same time, deviants to the lower-pitched, but not higher-pitched, tone within the two-tone dyad elicited a reduced MMNm compared to when each tone was presented alone, indicating that the representations of two pitches are not completely independent.
本研究考察了在注意前听觉记忆中，两个同时出现的音调是具有独立的记忆表征还是整合的表征。当高音调或低音调以25%的概率出现音调变化时，检测失配负波场，从而使双音调二元组的总偏差率为50%。两个音调中的偏差刺激均获得了清晰的MMNm，证实了同时出现的音调具有独立的记忆痕迹。同时，与单独呈现每个音调时相比，双音调二元组中低音调而非高音调的偏差刺激引发的MMNm减小，表明两个音调的表征并非完全独立。
