Aids Brain Function Sharpens Mental Focus and Helps Improve Memory Phosphatidylserine PS is a natural substance found in brain cell membranes. PS plays a role in neurotransmission and supports brain function. Some studies show that phospholipids such as Phosphatidylserine may decline with age. That is why supplementation is so important. Very limited and preliminary scientific research suggests that PS may reduce the risk of cognitive dysfunction in the elderly. The FDA concludes that there is very little scientific evidence supporting this claim.