Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 720 Rutland Ave., Traylor 410, Baltimore, MD 21025, United States.
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 720 Rutland Ave., Traylor 410, Baltimore, MD 21025, United States.
Hear Res. 2023 Mar 15;430:108722. doi: 10.1016/j.heares.2023.108722. Epub 2023 Feb 12.
The common marmoset (Callithrix jacchus) is a small arboreal New World primate which has emerged as a promising model in auditory neuroscience. One potentially useful application of this model system is in the study of the neural mechanism underlying spatial hearing in primate species, as the marmosets need to localize sounds to orient their head to events of interest and identify their vocalizing conspecifics that are not visible. However, interpretation of neurophysiological data on sound localization requires an understanding of perceptual abilities, and the sound localization behavior of marmosets has not been well studied. The present experiment measured sound localization acuity using an operant conditioning procedure in which marmosets were trained to discriminate changes in sound location in the horizontal (azimuth) or vertical (elevation) dimension. Our results showed that the minimum audible angle (MAA) for horizontal and vertical discrimination was 13.17° and 12.53°, respectively, for 2 to 32 kHz Gaussian noise. Removing the monaural spectral cues tended to increase the horizontal localization acuity (11.31°). Marmosets have larger horizontal MAA (15.54°) in the rear than the front. Removing the high-frequency (> 26 kHz) region of the head-related transfer function (HRTF) affected vertical acuity mildly (15.76°), but removing the first notch (12-26 kHz) region of HRTF substantially reduced the vertical acuity (89.01°). In summary, our findings indicate that marmosets' spatial acuity is on par with other species of similar head size and field of best vision, and they do not appear to use monaural spectral cues for horizontal discrimination but rely heavily on first notch region of HRTF for vertical discrimination.
普通狨（Callithrix jacchus）是一种小型树栖新世界灵长类动物，已成为听觉神经科学中很有前途的模型。该模型系统的一个潜在有用的应用是研究灵长类物种空间听觉的神经机制，因为狨猴需要定位声音，以将头部转向感兴趣的事件，并识别其无法看到的发声同种个体。然而，解释有关声音定位的神经生理数据需要了解感知能力，而狨猴的声音定位行为尚未得到很好的研究。本实验使用操作性条件反射程序测量了声音定位的敏锐度，其中，狨猴被训练以辨别水平（方位角）或垂直（仰角）维度中声音位置的变化。我们的结果表明，水平和垂直辨别时的最小可听角度（MAA）分别为 2 至 32 kHz 高斯噪声的 13.17°和 12.53°。去除单耳频谱线索往往会增加水平定位的敏锐度（11.31°）。狨猴的水平 MAA（15.54°）在后侧比在前侧大。去除头部相关传递函数（HRTF）的高频（> 26 kHz）区域对垂直敏锐度有轻微影响（15.76°），但去除 HRTF 的第一个缺口（12-26 kHz）区域会大大降低垂直敏锐度（89.01°）。综上所述，我们的研究结果表明，狨猴的空间敏锐度与其他具有相似头部大小和最佳视野的物种相当，它们似乎不会使用单耳频谱线索进行水平辨别，而是严重依赖 HRTF 的第一个缺口区域进行垂直辨别。
