Nottebohm F
Rockefeller University Field Research Center, Millbrook, NY 12545.
Trends Neurosci. 1991 May;14(5):206-11. doi: 10.1016/0166-2236(91)90107-6.
The most widely accepted hypothesis of vocal imitation in birds pre-dates many recent studies on the behavior, anatomy, physiology and cell biology of this phenomenon. It states that vocal learning involves two steps: (1) an auditory memory is laid down, and then (2) vocal output is modified until the auditory feedback it generates matches the model. This black-box model of vocal imitation disregards circuitry. We now know that the brain pathways for vocal learning in birds include a series of well-defined nuclei and projections. Some of these nuclei and projections develop late in ontogeny, at the time when auditory models are first acquired and imitated. We also know that the pathways involved in song production respond to sound, an observation that blurs the demarcation between what is an auditory and what is a motor circuit. These and other recent discoveries call for a reassessment of the mechanisms and origins of vocal learning in birds and mammals.
鸟类中关于声音模仿最广泛接受的假说早于许多近期关于这一现象的行为、解剖学、生理学和细胞生物学的研究。该假说认为声音学习涉及两个步骤：（1）建立听觉记忆，然后（2）修改声音输出，直到其产生的听觉反馈与模型匹配。这种声音模仿的黑箱模型忽略了神经回路。我们现在知道鸟类声音学习的脑通路包括一系列明确的神经核团和投射。其中一些神经核团和投射在个体发育后期才发育，此时听觉模型首次被获取和模仿。我们还知道参与发声的通路对声音有反应，这一观察模糊了听觉回路和运动回路之间的界限。这些以及其他近期发现要求重新评估鸟类和哺乳动物声音学习的机制和起源。
