Recanzone G H, Schreiner C E, Merzenich M M
Coleman Laboratory, Department of Otolaryngology, University of California, San Francisco 94143-0732.
J Neurosci. 1993 Jan;13(1):87-103. doi: 10.1523/JNEUROSCI.13-01-00087.1993.
Previous studies have shown that the tonotopic organization of primary auditory cortex is altered subsequent to restricted cochlear lesions (Robertson and Irvine, 1989) and that the topographic reorganization of the primary somatosensory cortex is correlated with changes in the perceptual acuity of the animal (Recanzone et al., 1992a-d). Here we report an increase in the cortical area of representation of a restricted frequency range in primary auditory cortex of adult owl monkeys that is correlated with the animal's performance at a frequency discrimination task. Monkeys trained for several weeks to discriminate small differences in the frequency of sequentially presented tonal stimuli revealed a progressive improvement in performance with training. At the end of the training period, the tonotopic organization of Al was defined by recording multiple-unit responses at 70-258 cortical locations. These responses were compared to those derived from three normal monkeys and from two monkeys that received the same auditory stimuli but that were engaged in a tactile discrimination task. The cortical representation, the sharpness of tuning, and the latency of the response were greater for the behaviorally relevant frequencies of trained monkeys when compared to the same frequencies of control monkeys. The cortical area of representation was the only studied parameter that was correlated with behavioral performance. These results demonstrate that attended natural stimulation can modify the tonotopic organization of Al in the adult primate, and that this alteration is correlated with changes in perceptual acuity.
先前的研究表明，在局限性耳蜗损伤后，初级听觉皮层的音频拓扑组织会发生改变（罗伯逊和欧文，1989年），并且初级体感皮层的拓扑重组与动物感知敏锐度的变化相关（雷坎佐内等人，1992年a - d）。在此，我们报告成年枭猴初级听觉皮层中一个受限频率范围的皮层代表区域增加，这与动物在频率辨别任务中的表现相关。经过数周训练以辨别相继呈现的音调刺激频率微小差异的猴子，随着训练其表现逐渐改善。在训练期结束时，通过在70 - 258个皮层位置记录多单元反应来确定A1区的音频拓扑组织。将这些反应与来自三只正常猴子以及两只接受相同听觉刺激但进行触觉辨别任务的猴子的反应进行比较。与对照猴子相同频率相比，训练猴子行为相关频率的皮层代表、调谐锐度和反应潜伏期更大。皮层代表区域是唯一与行为表现相关的研究参数。这些结果表明，受到关注的自然刺激可改变成年灵长类动物A1区的音频拓扑组织，并且这种改变与感知敏锐度的变化相关。
