I honestly am not familiar with this particular category. I was hoping to see something from Usana and this is what I found:
"Ginkgo-PS combines standardized Ginkgo biloba extract and phosphatidylserine for healthy mental and cognitive function.
Ginkgo biloba extract contains a mix of bioflavonoids that provide antioxidant activity in the brain to fight free-radical damage. Its most important role, however, is enhancing blood circulation throughout the body and improving oxygenation to brain cells.
Phosphatidylserine is the ideal complement to Ginkgo biloba. It is a component of all cell membranes and is essential to proper cell function. It is found in highest concentration in the cell membrane of neural tissues. As a nutrient, phosphatidylserine facilitates nerve cell membrane functions."
Just an idea, that's all. Hope it helps a little :-)