User assistance systems are often invoked automatically based on simple triggers (e.g., the assistant pops up after the user has been idle for some time) or they require users to invoke them manually. Both invocation modes have their weaknesses. Therefore, we argue that, ideally, the assistance should be invoked intelligently based on the users’ actual need for assistance. In this paper, we propose a research project investigating the role of users’ cognitive-affective states when providing assistance using NeuroIS measurements. Drawing on the theoretical foundations of the Attentional Control Theory, we propose an experiment that helps to understand how cognitive-affective states can serve as indicators for the best point of time for the invocation of user assistance systems. The research described in this paper will ultimately help to design intelligent invocation of user assistance systems.