Neural Correlates Of Insight: From The Compound Remote Associate Problems

The early Gestalt psychologist Kohler observed chimpanzees and found that the chimpanzees could resolve problems suddenly, so he thought insight problem-solving was a process of reconstructing the whole situation with an "Aha!" experience. The occurrence of "Aha!" experience means rethinking some basic assumptions about the problem content, which happens in a relatively sudden and unpredictable manner. Developed brain imaging techniques such as event-related potentials (ERPs) have made it possible to explore the neural basis of insight problem solving.By applying a variety of tasks and experimental procedures, researchers had found some possible brain regions correlates of insight. For example, Luo et al. recorded neural activities using fMRI, and correlated these with cognitive insight by providing a trigger (the solution) to catalyze insightful riddle solving processes. Results showed that insight riddle-solving was associated with activity primarily in the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC). In a series of studies using compound remote associate (CRA) problems, Bowden and Beeman explored the brain mechanism of insight problem solving by using subjective reports. In their studies, subjects first saw three problem words (french, car, shoe), and then generated a solution (camp) that could form a compound word or phrase with each problem word (car horn, french horn, shoehorn). The solution word could precede or follow each problem word. And then, subjects verbalized their solution and pressed buttons indicating whether they solved the problem with or without insight. Their results revealed an increased signal in the right anterior superior temporal gyrus for insight but not non-insight solutions, and scalp EEG recordings revealed a sudden burst of high-frequency (gamma-band) neural activity in the same region just before insight, but not non-insight solutions. Qiu et al used Chinese logogriphs to study the neural correlates of insight problem solving. They found successful guessed logogriphs elicited some ERP deflections (P200-600, N1500-2000) and the related brain areas (ACC, the parahippocampal gyrus). To sum up, conclusions were inconsistent and neural basis of insight still is an ambiguous issue. Therefore, on the basis of Bowden and Beeman's study, we used CRAs to study the neural correlates of insight. The study included two Event-related potentials (ERPs) studies.The first study included two conditions:insight condition and non-insight condition. Results showed that Insight condition elicited a more negative ERP deflection (N800-1600) than did Non-Insight condition in the time window of 800-1600 ms. Dipole source analysis showed that the generators of N800-1600 were localized in the left prefrontal cortex (PFC) and the anterior cingulate cortex (ACC), which might be related to break mental sets during insight problem solving. Then, a greater slow negative ERP deflection (N1800-2300) in Insight condition as compared to Non-Insight condition was observed in the time window of 1800-2300 ms. Dipole source analysis showed that the generator of N1800-2300 was localized in the precuneus, which might be involved in the process of spatial information.The second study's results showed that Insight condition elicited a more negative ERP deflection (N700-1000) than did Non-Insight condition in the time window of 700-1000 ms. Dipole source analysis showed that the generators of N700-1000 were localized in the right superior frontal gyrus, which might be related to retrieval of heuristic information during insight problem solving. Then, a greater slow negative ERP deflection (N1600-2000) in Insight condition as compared to Non-Insight condition was observed in the time window of 1600-2000 ms. Dipole source analysis showed that the generator of N1600-2000 was localized in the parahippocampal gyrus, which might be involved in forming novel associations during insight problem solving.Two studies found that Insight condition elicited more negative ERP deflections (N800-1600, N1800-2300å’ŒN700-1000, N1600-2000) than did Non-Insight condition. Therefore, the results might be proved the consistency of cross-cultural research of insight.