Agglomerator++: Interpretable part-whole hierarchies and latent space representations in neural networks

Deep neural networks achieve outstanding results in a large variety of tasks, often outperforming human experts. However, a known limitation of current neural architectures is the poor accessibility in understanding and interpreting the network’s response to a given input. This is directly related to the huge number of variables and the associated non-linearities of neural models, which are often used as black boxes. This lack of transparency, particularly in crucial areas like autonomous driving, security, and healthcare, can trigger skepticism and limit trust, despite the networks’ high performance. In this work, we want to advance the interpretability in neural networks. We present Agglomerator++, a framework capable of providing a representation of part-whole hierarchies from visual cues and organizing the input distribution to match the conceptual-semantic hierarchical structure between classes. We evaluate our method on common datasets, such as SmallNORB, MNIST, FashionMNIST, CIFAR-10, and CIFAR-100, showing that our solution delivers a more interpretable model compared to other state-of-the-art approaches. Our code is available at https://mmlab-cv.github.io/Agglomeratorplusplus/ . • We introduce a novel model, called Agglomerator++, mimicking the functioning of the cortical columns in the human brain. • Our solution provides interpretability of relationships in data, namely the hierarchical organization of the feature space. • We introduce positional encoding and input masking during pre-training for self- supervised reconstruction. • This neural representation is more efficient and closely resembles human lexical similarities.