Unraveling Babel: Exploring Multilingual Activation Patterns within Large Language Models

Recently, LLMs have achieved tremendous breakthroughs in the field of language processing, yet their mechanisms in processing multiple languages remain agnostic. Therefore, in this work we study the multilingual activation patterns of LLMs. By transforming the original LLMs into a Mixture of Experts (MoE) architecture, we analyze the expert activation patterns when processing various languages and demonstrate the connections of these activation patterns at the level of language families. We discover the existence of non-language-specific neurons as well as language-specific activation neurons. Further exploration even showcases that merely leveraging high-frequency activation neurons can accelerate inference while maintaining comparable performance. These findings shed light on the LLMs' multilingual processing mechanism, and are of significant importance in guiding the multilingual training and model pruning of LLMs.