Tamura Hiroshi
Graduate School of Frontier Biosciences, The University of Osaka, Suita, Osaka, 565-0871, Japan.
Center for Information and Neural Networks, Suita, Osaka, 565-0871, Japan.
Sci Rep. 2025 Jan 2;15(1):67. doi: 10.1038/s41598-024-84981-1.
Functional modular organization is observed in a variety of cortical areas in the brain. In the visual cortex of primates, adjacent neurons often respond to the same visual submodality, such as color or orientation, and have a similar preferred orientation or preferred color. However, it remains unclear why functional modular organization emerges in the cerebral cortex. In the present study, I constructed and trained a multistream convolutional neural network to examine whether filters in the same stream acquire similar properties. Although filters in the same stream were able to develop any structures, they acquired similar degrees of orientation and color selectivity and preferred similar orientations and colors. The deletion of filters in a single stream that had similar degrees of stimulus selectivity resulted in larger decreases in classification accuracy than the deletion of those that did not. By contrast, the deletion of filters in a single stream that shared a preferred stimulus resulted in similar decreases in classification accuracy to the deletion of those that did not. Together, these findings suggest that filters with similar degrees of stimulus selectivity in the same stream are required for optimal task performance of the multistream convolutional neural network, and probably of the brain.
在大脑的各种皮质区域中都观察到了功能模块化组织。在灵长类动物的视觉皮质中，相邻神经元通常对相同的视觉子模态做出反应，例如颜色或方向，并且具有相似的偏好方向或偏好颜色。然而，大脑皮质中为何会出现功能模块化组织仍不清楚。在本研究中，我构建并训练了一个多流卷积神经网络，以检查同一流中的滤波器是否获得相似的特性。尽管同一流中的滤波器能够形成任何结构，但它们获得了相似程度的方向和颜色选择性，并且偏好相似的方向和颜色。删除具有相似程度刺激选择性的单个流中的滤波器，导致分类准确率的下降幅度大于删除那些没有相似程度刺激选择性的滤波器。相比之下，删除共享偏好刺激的单个流中的滤波器，导致分类准确率的下降幅度与删除那些没有共享偏好刺激的滤波器相似。总之，这些发现表明，同一流中具有相似程度刺激选择性的滤波器是多流卷积神经网络（可能还有大脑）实现最佳任务性能所必需的。
