Neural correlates of the “Aha” experiences: Evidence from an fMRI study of insight problem solving

Abstract

In the present study, we used learning–testing paradigm to examine brain activation of “Aha” effects with event-related functional magnetic resonance imaging (fMRI) during solving Chinese logogriphs. Blood oxygenation level-dependent fMRI contrasts between Aha and No-aha conditions were measured. Increased activities in the precuneus (BA 19/7), the left inferior/middle frontal gyrus (BA 9/6), the inferior occipital gyrus (BA 18), and the cerebellum were specifically associated with the “Aha” effects. The results indicate that (1) the precuneus might be involved in successful prototype events retrieval, (2) the left inferior frontal/middle frontal gyrus might be involved in forming novel association and breaking mental sets, (3) the inferior occipital gyrus and the cerebellum might be involved in re-arrangement of visual stimulus and deployment of attentional resources.

Introduction

The early Gestalt psychologists thought that insightful problem solving resulted from reconstructing the whole problem. The occurrence of an “Aha” experience means rethinking about some basic assumptions about the problem content and realizing a new solution, which happens in a relatively sudden and unpredictable manner (Kohler, 1925). During the last century, cognitive psychologists studied the processes of insight with respect to problem solving skills, using human and animal subjects (e.g., Kohler, 1925, Kaplan and Simon, 1990, MacGregor et al., 2001). However, the cognitive mechanisms of insight remain largely unknown.

Brain-imaging techniques such as functional magnetic resonance imaging (fMRI) have made it possible for us to record precisely the brain activation associated with insightful problem solving. For example, Luo and Niki, 2003, Luo et al., 2004 recorded neural activities using fMRI and correlated activities associated with cognitive insight by providing a trigger (the solution) to catalyze insightful riddle solving processes, and found that insightful riddle solving was associated with activities primarily in the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC). In a series of studies using the compound remote associates problem (CRA, e.g., boot, summer, ground; solutions: camp) and fMRI, Jung-Beeman et al. (2004) and Bowden et al. (2005) revealed an increased signal in the right anterior superior temporal gyrus for the “Aha” effects.

It is undoubtedly an innovation to adopt riddles as experimental materials and to catalyze insight by presenting the correct answers so as to reveal the activity of the brain (e.g., Luo and Niki, 2003, Qiu et al., 2006). However, it was not an insight in the strict sense but an apperception when subjects understand the solution after being told it (e.g., Metcalfe, 1986, Smith and Kounios, 1996). Research demonstrated that the cognitive processes in insight problem solving through participants' actively solving the problem versus passively understanding the answer are different. In the case of getting an answer, there might be a lack of problem restructuring or impasse experience which was typical of insightful problem solving (Luo and Knoblich, 2007).

Therefore, in the present study, a novel model using learning–testing experimental paradigm (for details see the Procedure) was adopted to explore the brain mechanisms of insightful problem solving. In this study, subjects had to find a solution on their own initiative rather than receive answers passively. We believe that one needs to retrieve a prior experience with a similar problem to form a new relation between the problem elements in order to solve an analogous insightful problem. Based on the previous work (e.g., Luo and Niki, 2003; Bowden and Jung-Beeman, 2003, Bowden et al., 2005), we predicted that “Aha” effects will activate regions in the medial frontal/ACC (breaking mental set), the anterior temporal gyrus (forming novel association), the medial parietal association cortex or precuneus (successfully retrieving heuristic information).