Kamali Fatemeh, Suratgar Amir Abolfazl, Menhaj Mohammadbagher, Abbasi-Asl Reza
Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Department of Neurology, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, United States of America.
PLoS Comput Biol. 2025 Feb 19;21(2):e1012822. doi: 10.1371/journal.pcbi.1012822. eCollection 2025 Feb.
Voxelwise encoding models based on convolutional neural networks (CNNs) are widely used as predictive models of brain activity evoked by natural movies. Despite their superior predictive performance, the huge number of parameters in CNN-based models have made them difficult to interpret. Here, we investigate whether model compression can build more interpretable and more stable CNN-based voxelwise models while maintaining accuracy. We used multiple compression techniques to prune less important CNN filters and connections, a receptive field compression method to select receptive fields with optimal center and size, and principal component analysis to reduce dimensionality. We demonstrate that the model compression improves the accuracy of identifying visual stimuli in a hold-out test set. Additionally, compressed models offer a more stable interpretation of voxelwise pattern selectivity than uncompressed models. Finally, the receptive field-compressed models reveal that the optimal model-based population receptive fields become larger and more centralized along the ventral visual pathway. Overall, our findings support using model compression to build more interpretable voxelwise models.
基于卷积神经网络(CNN)的体素编码模型被广泛用作自然电影诱发大脑活动的预测模型。尽管它们具有卓越的预测性能,但基于CNN的模型中大量的参数使其难以解释。在这里,我们研究模型压缩是否可以在保持准确性的同时构建更具可解释性和更稳定的基于CNN的体素模型。我们使用多种压缩技术来修剪不太重要的CNN滤波器和连接,一种感受野压缩方法来选择具有最佳中心和大小的感受野,以及主成分分析来降低维度。我们证明,模型压缩提高了在保留测试集中识别视觉刺激的准确性。此外,与未压缩模型相比,压缩模型对体素模式选择性提供了更稳定的解释。最后,感受野压缩模型表明,基于最优模型的群体感受野沿腹侧视觉通路变得更大且更集中。总体而言,我们的研究结果支持使用模型压缩来构建更具可解释性的体素模型。