Morris J S, Friston K J, Dolan R J
University College Hospitals School of Medicine, London, UK.
Proc Biol Sci. 1998 Apr 22;265(1397):649-57. doi: 10.1098/rspb.1998.0343.
Experience-dependent plasticity of receptive fields in the auditory cortex has been demonstrated by electrophysiological experiments in animals. In the present study we used PET neuroimaging to measure regional brain activity in volunteer human subjects during discriminatory classical conditioning of high (8000 Hz) or low (200 Hz) frequency tones by an aversive 100 dB white noise burst. Conditioning-related, frequency-specific modulation of tonotopic neural responses in the auditory cortex was observed. The modulated regions of the auditory cortex positively covaried with activity in the amygdala, basal forebrain and orbitofrontal cortex, and showed context-specific functional interactions with the medial geniculate nucleus. These results accord with animal single-unit data and support neurobiological models of auditory conditioning and value-dependent neural selection.
动物电生理实验已证明听觉皮层感受野的经验依赖性可塑性。在本研究中，我们使用正电子发射断层扫描（PET）神经成像技术，来测量志愿者人类受试者在通过100分贝厌恶白噪声爆发对高（8000赫兹）或低（200赫兹）频率音调进行辨别性经典条件反射过程中的局部脑活动。观察到听觉皮层中与条件反射相关的、频率特异性的声调定位神经反应调制。听觉皮层的调制区域与杏仁核、基底前脑和眶额皮层的活动呈正相关，并与内侧膝状体表现出特定情境下的功能相互作用。这些结果与动物单单位数据一致，并支持听觉条件反射和价值依赖性神经选择的神经生物学模型。
