Braun Martin, Chaloupka Vladimir
Neuroscience of Music, Gansbyn 14, S-67195 Klässbol, Sweden.
Hear Res. 2005 Dec;210(1-2):85-92. doi: 10.1016/j.heares.2005.05.015. Epub 2005 Sep 21.
Octave-circular pitch perception, the repetition of pitch scale qualities when surpassing the octave interval, has been observed in behavioral data from humans and monkeys, but the underlying anatomy and physiology is still unknown. Here we analyze octave circularity in a concert pianist with absolute pitch, both under medication with the neurotropic drug carbamazepine (CBZ) and without medication. Analysis of 4619 responses in a pitch identification task revealed an internal tone-scale representation, based on the norm-tone scale re A4=440 Hz, with an octave-circular pattern of strongly and weakly represented tones. CBZ caused a global down-shift of pitch (ca. 1 semitone at 500 Hz), but no down-shift of the octave-circular pattern of tone characteristics. This pattern was similar in the six tested octave ranges (32.7-2093 Hz), both under the control and the CBZ condition. Pattern repetition always occurred at octave intervals and did not reflect the stretched octaves of piano tuning. The results indicate that CBZ influences pitch detection peripheral of an octave-circular pitch representation. Thus they support previous evidence for pitch detection in the auditory midbrain and for octave-circular pitch mapping in the auditory thalamus.
倍频程循环音高感知，即超过倍频程间隔时音高标度特性的重复，已在人类和猴子的行为数据中被观察到，但其潜在的解剖学和生理学机制仍然未知。在此，我们分析了一位具有绝对音高的音乐会钢琴家在服用神经营养药物卡马西平（CBZ）和未服药两种情况下的倍频程循环性。对音高识别任务中的4619次反应进行分析后发现，基于标准音高标度（A4 = 440 Hz）存在一种内部音高标度表征，具有强弱表征音调的倍频程循环模式。CBZ导致音高整体下移（500 Hz时约下移1个半音），但音调特征的倍频程循环模式没有下移。在对照和CBZ条件下，六个测试的倍频程范围（32.7 - 2093 Hz）中的这种模式相似。模式重复总是在倍频程间隔处发生，并不反映钢琴调音中的拉伸倍频程。结果表明，CBZ影响倍频程循环音高表征外周的音高检测。因此，它们支持了先前关于听觉中脑音高检测和听觉丘脑倍频程循环音高映射的证据。
