Understanding Relevance: An fMRI Study

Relevance is one of the key concepts in Information Retrieval (IR). A huge body of research exists that attempts to understand this concept so as to operationalize it for IR systems. Despite advances in the past few decades, answering the question "How does relevance happen?" is still a big challenge. In this paper, we investigate the connection between relevance and brain activity. Using functional Magnetic Resonance Imaging (fMRI), we measured the brain activity of eighteen participants while they performed four topical relevance assessment tasks on relevant and non-relevant images. The results of this experiment revealed three brain regions in the frontal, parietal and temporal cortex where brain activity differed between processing relevant and non-relevant documents. This is an important step in unravelling the nature of relevance and therefore better utilising it for effective retrieval.