Chi & Snyder (2011), found an innovative way to increase insightfulness. They used a well-known experimental paradigm involving ”matchstick arithmetic”. Participants were asked to correct a false arithmetic statement, presented in Roman numerals constructed from matchsticks, by moving one stick from one position to another position without adding or removing a stick.
Once we have figured out a solution to a problem we often have a hard time generating new insights to generate more solutions. Although some research has found people with brain lesions are less prone to this effect, part of the reason that this placement is successful in improving insightfulness is because the left temporal lobe is inhibited.
The findings from this placement actually improved scores three-fold which is the strongest cognitive enhancement the study is aware of in brain stimulations. They believe the reason insight was improved so much was due to the decreased cortical excitability of the left hemisphere, increased excitability of the right hemisphere or perhaps a combination of both.
Siever, D. (2013). Transcranial DC Stimulation. Neuroconnections, Spring Issue, 33-40. http://www.mindalive.com/1_0/article%2011.pdf.
here is a map that shows the t7 and t8 positions.
http://www.brainm.com/software/pubs/dg/BA_10-20_ROI_Talairach/nearesteeg.htm