I read this question Are there benefits to learning to write with your non-dominant hand?. It got me thinking.Disclaimer:This is not a self help question I am using myself to illustrate the condition.The condition:As a child I began life as a left hander. I did everything with my left hand, including playing the guitar, writing, drawing, card playing (I was not betting on these card games). Early on , around 5-6 I changed handedness. I became right handed, or partially ambidextrous. I now play guitar, write and draw with my right hand. I still play cards (not for money) with my left hand. I can attend to my matters of hygiene equally well with either hand. I make reference to this, as it is surprising to find how difficult it is for people to clean themselves with their non-dominant hand. My left handed writing is inferior to my right hand. I am not truly ambidextrous. No one coerced or encouraged me (although I did attend a catholic school with nuns) to write with my right hand.The question:What is the phenomena of spontaneous change of handedness?Are there studies showing any correlations with the brain and such phenomena?How is someone like this defined; ie right handed, left handed, ambidextrous?  
Spontaneous change of handedness
developmental psychology;personality;cognitive neuroscience;motor;lateralization