SAFR: Neuron Redistribution for Interpretability
This work addresses interpretability issues for users of deep learning models, but it is incremental as it builds on existing regularization techniques.
The paper tackles the problem of reduced interpretability in deep neural networks due to feature superposition by introducing SAFR, a regularization method that promotes monosemantic representations for important tokens and polysemanticity for correlated token pairs, evaluated on transformer models for classification tasks with maintained prediction performance.
Superposition refers to encoding representations of multiple features within a single neuron, which is common in deep neural networks. This property allows neurons to combine and represent multiple features, enabling the model to capture intricate information and handle complex tasks. Despite promising performance, the model's interpretability has been diminished. This paper presents a novel approach to enhance model interpretability by regularizing feature superposition. We introduce SAFR, which simply applies regularizations to the loss function to promote monosemantic representations for important tokens while encouraging polysemanticity for correlated token pairs, where important tokens and correlated token pairs are identified via VMASK and attention weights respectively. We evaluate SAFR with a transformer model on two classification tasks. Experiments demonstrate the effectiveness of SAFR in improving model interpretability without compromising prediction performance. Besides, SAFR provides explanations by visualizing the neuron allocation within the intermediate layers.