Even though I have no link-able proof, I believe the subconscious has much to do (if not everything) with how the body instructs itself to the way it metabolizes food. An article today fyr, coming close since they again refer to the concious only. Which is not the real true answer imo. =) http://www.cnn.com/2007/LIVING/personal/06/29/in.your.head/index.html
1g of 50% GPC which yields 500mg of active. The dopa dose is dependent on the concentration, but typically 100-200mg of the active compound.