Uniformity and nonuniformity of neural activities correlated to different insight problem solving

• Different insight problems induce a common N350-500 over the central scalp.
• Semantic punny riddle activates the bilateral temporal cortices prior to solution.
• Homophonic punny riddle activates the left frontal and right temporal areas.
• Diverse insight problems are the same in detecting conflicts, but different in solving.

Previous studies on the neural basis of insight reflected weak consistency except for the anterior cingulate cortex. The present work adopted the semantic and homophonic punny riddle to explore the uniformity and nonuniformity of neural activities correlated to different insight problem solving. Results showed that in the early period of insight solving, the semantic and homophonic punny riddles induced a common N350-500 over the central scalp. However, during −400 to 0 ms before the riddles were solved, the semantic punny riddles induced a positive event-related potential (ERP) deflection over the temporal cortex for retrieving the extensive semantic information, while the homophonic punny riddles induced a positive ERP deflection over the temporal cortex and a negative one in the left frontal cortex which might reflect the semantic and phonological information processing respectively. Our study indicated that different insight problem solving should have the same cognitive process of detecting cognitive conflicts, but have different ways to solve the conflicts.