If you want to sharpen your brain and improve your memory, the best supplement is a distilled fish oil from species like hoki and tuna.
Vinpocetine has a lot of effects with variable importance on increasing attention span, memory, and concentration. Effective fish oil brain sharpener supplement contains at least 250mg of DHA per 1000mg of oil. These factors are aging, neurotransmitter depletion and a lot more.