In insight problem solving solutions with AHA! experience have been assumed to be the consequence of restructuring ofa problem which usually takes place shortly before the solution. However, evidence from priming studies suggests thatsolutions with AHA! are not spontaneously generated during the solution process but already relate to prior subliminalprocessing. We test this hypothesis by conducting an fMRI study using a modified compound remote associates paradigmwhich incorporates semantic priming. We observe stronger brain activity in bilateral anterior insulae already shortly aftertrial onset in problems that were later solved with than without AHA!. This early activity was independent of semanticpriming but may be related to other lexical properties of attended words helping to reduce the amount of solutions to lookfor. In contrast, there was more brain activity in bilateral anterior insulae during solutions that were solved without thanwith AHA!. This timing (after trial start / during solution) x solution experience (with / without AHA!) interaction wassignificant. The results suggest that a) solutions accompanied with AHA! relate to early solution-relevant processing andb) both solution experiences differ in timing when solution-relevant processing takes place. In this context, we discuss thepotential role of the anterior insula as part of the salience network involved in problem-solving by allocating attentionalresources.

In verbal creative problems like compound remote associates (CRAs), the solution is semantically distant and there is nopredefined path to the solution. Therefore, people first search through the space of possible solutions before retrieving thecorrect semantic content by extending their search space. We assume that search and solution are both part of a semanticcontrol process which involves the inferior frontal gyrus (IFG). Furthermore, the degree of the IFG involvement dependson how much the search space needs to be extended, i.e. how semantically distant the solution is. To demonstrate this,we created a modified CRA paradigm which systematically modulates the semantic distance from the first target wordto the solution via priming. We show that brain areas (left inferior frontal gyrus and middle temporal gyrus) associatedwith semantic control are already recruited during search. In addition, we found a linear correlation between the BOLDactivation of the IFG (pars orbitalis and triangularis) and the search space extension. However, this linear relationshipcould only be observed during and shortly before the correct solution but not during search. We discuss the role of the IFGin accessing semantically distant information during verbal creative problem solving.