We had predicted this area might be involved because it seems also to be important for drawing distantly related information together when comprehending complex language. This is just what is needed to overcome impasse and solve a problem with insight. This fMRI result is also consistent with previous results from our lab demonstrating RH advantages in solution priming (fast responses to solution words) and solution decisions, for words presented to the RH, via the left visual field, compared to words presented directly to the LH, via the right visual field (Beeman & Bowden, 2000; Bowden & Beeman, 1998; Jung-Beeman & Bowden 2003).
.. The EEG experiment provided two additional pieces of information. First of all, the RH temporal lobe activity appeared as a sudden burst of high-frequency (gamma band) activity, relative to solutions achieved without insight. This neural activity is often associated with complex cognitive processing, in particular binding elements of a percept together as it comes into a consciousness.
A second, unexpected EEG effect also was observed: About 1.5 seconds prior to insight solutions, an increase in lower frequency (alpha band) activity appeared over the right posterior cortex. This effect disappeared precisely when the high-frequency activity began over the right temporal lobe. This may reflect “gating,” or attenuation, of visual input, allowing initially weak solution-related activity to gain strength, then burst into consciousness as an insight. This is like closing your eyes so you can concentrate when you are trying to solve a difficult problem but in this case, your brain is blocking out just the visual inputs to your right hemisphere.