Towards understanding neuroscience of realisation of information need in light of relevance and satisfaction judgement

Understanding how to satisfy searchers' information need (IN) is the main goal of Information Retrieval (IR) systems. In this study, we investigate the relationships between information need and the two key concepts of relevance and satisfaction from the perspective of neuroscience. We utilise functional Magnetic Resonance Imaging (fMRI) to measure the brain activity of twenty-four participants during performing a Question Answering (Q/A) task that, following the realisation of an information need, included the opportunity to initiate searches and evaluate returned documents. We contrast brain activity between the time of realisation of information need (IN) and two other periods, relevance judgement (RJ), i.e. IN vs RJ, and satisfaction judgement (SJ), i.e. IN vs SJ. To interpret these results, we use meta-analytic techniques of reverse inference to identify the functional significance of the discovered brain regions. The results provide consistent evidence of the involvement of several cognitive functions, including imagery, attention, planning, calculation and working memory. Our findings lead us to obtain a better understanding associated with the characteristic of information need and its relationships to relevance and satisfaction.