To compensate for the hormonal surges a specific part of the female brain goes into overdrive during PMS. It is believed that this might compensate for 'emotional instability' during this period (i'm treading on eggs here I believe). http://www.nature.com/news/2005/051024/full/051024-2.html We just wonder if there is enough brain capacity left to do some thinking!? Or is all the blood and nutrient flow directly piped into this one specific part of the brain? Once again we dare to go were scientists do not.