Distributional reasoning in LLMs: Parallel reasoning processes in multi-hop reasoning
This provides insights into the thought processes of LLMs, which is significant for researchers in AI and cognitive science, though it is incremental in analyzing existing models.
The paper tackled the problem of understanding internal reasoning processes in large language models (LLMs) during multi-hop reasoning tasks, and found that the prediction process can be modeled with a linear transformation between semantic spaces, with middle layers generating interpretable embeddings representing potential intermediate answers and parallel reasoning paths, even when the model lacks necessary knowledge.
Large language models (LLMs) have shown an impressive ability to perform tasks believed to require thought processes. When the model does not document an explicit thought process, it becomes difficult to understand the processes occurring within its hidden layers and to determine if these processes can be referred to as reasoning. We introduce a novel and interpretable analysis of internal multi-hop reasoning processes in LLMs. We demonstrate that the prediction process for compositional reasoning questions can be modeled using a simple linear transformation between two semantic category spaces. We show that during inference, the middle layers of the network generate highly interpretable embeddings that represent a set of potential intermediate answers for the multi-hop question. We use statistical analyses to show that a corresponding subset of tokens is activated in the model's output, implying the existence of parallel reasoning paths. These observations hold true even when the model lacks the necessary knowledge to solve the task. Our findings can help uncover the strategies that LLMs use to solve reasoning tasks, offering insights into the types of thought processes that can emerge from artificial intelligence. Finally, we also discuss the implication of cognitive modeling of these results.