Eichenbaum and colleagues observed that the same place did or did not activate the "goal-approach" cells in hippocampus depending on whether the place was the way for rats to approach specific goal. Parallel with this, the present neuroimage study revealed that, the same type of items could activate the hippocampus more when it was related to the task at hand than when it not. Participants were scanned by fMRI while they made judgments on the type of relationships contained in the word-pairs (e.g., Does the word pair, "furniture-table", contain a "category-exemplar" relationship?). Event-related analysis revealed that the forming of "task-related" association activated hippocampus more than that of "task-unrelated", even if it was the same type of items, and, this hippocampal difference was not caused by the different judgment requirements, nor by the effects of "yes" response. Consistently, the post-judgment cued-recall test exhibited a better retrieval performance for "task-related" associations than for the same type but "task-unrelated" associations. Results also showed that, the semantic re- latedness between the to-be-associated individual words (e.g., the related word pair "healthy-hospital" versus the unrelated word pair "price-way") was not enough to activate the hippocampus when it was "task-unrelated". Generally, we proposed that, through participating in forming of "task-related" asso- ciations and consolidating of episodic memory, hippocampus enabled the organism to keep the in- formation that owned great survival values in mind for future usage.
The first neuroimaging study of real-time brain activity during insight problem solving was conducted almost ten years ago. Many subsequent studies have used high-resolution event-related potentials (ERPs) and event-related functional magnetic resonance imaging (fMRI) to investigate the temporal dynamics and neural correlates of insight. Recent results on the neural underpinnings of insight have led researchers to propose a neural framework referred to as the "insightful brain". This putative framework represents the neural basis of the cognitive and affective processes that are involved in insight. The insightful brain may involve numerous brain regions, including the lateral prefrontal cortex, cingulate cortex, hippocampus, superior temporal gyrus, fusiform gyrus, precuneus, cuneus, insula and cerebellum. Functional studies have demonstrated that the lateral prefrontal cortex is responsible for mental set shifting and breaking during insight problem solving. The cingulate cortex is involved in the cognitive conflict between new and old ideas and progress monitoring. The hippocampus, superior temporal gyrus and fusiform gyrus form an integrated functional network that specializes in the formation of novel and effective associations. The effective transformation of problem representations depends on a non-verbal visuospatial information-processing network that comprises the precuneus and cuneus. The insula reflects cognitive flexibility and the emotional experience that is associated with insight. The cortical control of finger movements relies on the cerebellum.
Although previous studies have shown that sleep can inspire insight,it is still unclear whether meditation can promote insight.Meditation differs from other types of passive rest such as relaxation and sleep because it requires full consciousness andmindfulness of targets such as one's breathing.Forty-eight university students without meditation experience were recruited to learn a simple meditation technique.They were given a list of 10 insight problems to solve (the pre-test session).In this study,we focused on the unsolved problems and examined if they could be successfully solved after a 20min rest interval with or without meditation.Results showed that relative to the control group that listened to Chinese or English words and made a language judgment,the groups who learned meditation successfully solved significantly more failed problems from the pre-test session,providing direct evidence for the role of meditation in promoting insight.Further analysis showed that maintaining amindful and alert state during meditation (raising a hand to report every 10 deep breaths compared to every 100 deep breaths) resulted in more insight regarding the failed items from the pre-test session.This implies that it was watchfulness in meditation,rather than relaxation,that actually contributed to insight.Consistently,in the meditation session or control task,the percentage of alpha waves—a brain index of mental relaxation—was negatively correlated with insight.These results suggest a meditation-based insight-promoting mechanism different from that involved in passive rest such as relaxation and sleep.
