Multilingual large language models (LLMs) have greatly increased the ceiling of performance on non-English tasks. However the mechanisms behind multilingualism in these LLMs are poorly understood. Of particular interest is the degree to which internal representations are shared between languages. Recent work on neuron analysis of LLMs has focused on the monolingual case, and the limited work on the multilingual case has not considered the interaction between tasks and linguistic representations. In our work, we investigate how neuron activation is shared across languages by categorizing neurons into four distinct groups according to their responses across different languages for a particular input: all-shared, partial-shared, specific, and non-activated. This categorization is combined with a study of neuron attribution, i.e. the importance of a neuron w.r.t an output. Our analysis reveals the following insights: (i) the linguistic sharing patterns are strongly affected by the type of task, but neuron behaviour changes across different inputs even for the same task; (ii) all-shared neurons play a key role in generating correct responses; (iii) boosting multilingual alignment by increasing all-shared neurons can enhance accuracy on multilingual tasks. The code is available at https://github.com/weixuan-wang123/multilingual-neurons.

多语言大型语言模型（LLMs）的多语言机制对其内部表示的共享程度进行研究，并发现语言分享模式受任务类型和输入的影响，所有共享神经元在生成正确响应中起关键作用，增加所有共享神经元可以提高多语言任务的准确性。

分享的重要性：在LLMs中分析不同语言和任务的神经元