2/17/2006

Neural Correlates of Insight

What happens in the brain during an "a-ha" moment? As described by this paper from PLOS Biology, both fMRI and EEG evidence suggests distinct neural patterns of activity accompany the feeling of insight. Right anterior superior temporal gyrus activity increases along with increases in gamma band activity 300 msec prior to insight solutions. Although many of the same brain areas appear to be active during insight and normal problem solving processes, this specific pattern of results suggests that insight is caused by an abstract, holistic processing of information recruited from distant brain regions.

Is insight just another form of problem solving, differing only in emotional intensity or suddenness of onset? Such skepticism is warranted, given that insight often seems to occur with little or no warning, and is certainly accompanied by an intense feeling of accomplishment. But some recent results suggest that people continue to "think" about problems unconsciously - when primed with a potential solution, people are faster to make a decision when these words are presented to the right as opposed to left hemisphere - and similar processes might be at work during insight.

Right-hemispheric regions are particularly important for analyzing distant semantic relations, and indeed fMRI evidence from the PLOS paper implicates a right-hemisphere structure called the anterior superior temporal gyrus. This region is known to be important for integrating information across large cortical distances, and the right hemisphere more generally is known to be involved in relatively coarse-coding of semantic information and more holistic processing of visual information.

The researchers also demonstrated that just prior to the discovery of problem solutions, brief bursts of gamma activity (at anterior right electrodes) are predictive of whether the solution involved "insight" or not (see an animation here). Further, this insight-related activity was directly preceeded by alpha band (8–13 Hz) activity in the right posterior parietal electrodes up to 1.4 seconds before the solution response. This observation is consistent with an interpretation of alpha activity as a form of "cortical idling" in which bottom-up activity is essentially suppressed in order to allow more free-form associations to take place, such as those may take place in the right hemisphere. If alpha activity does serve such a role, it provides a new way of understanding previous reports that that alpha band power is involved in search and retrieval processes.

The same authors have several newer papers in Trends in Cognitive Sciences and Psychological Science, describing their approach and ways in which people can become biased towards insight-based problem solving strategies.

If you liked this, don't forget to dig it.

Related Posts:
Gamma Synchrony
Entangled Oscillations
Aha! Neural mechanisms immediately preceding the Aha!

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