As we get older our memories start to deplete. After a long life and full development of our sensory, short-term and long term memory the cognitive brain begins to head down hill at around the age 65. At about this age individuals start to develop or at risk of certain memory diseases like alzheimer's or dementia. These are diseases that effect the short-term memory first. The short-term meaning the memory system that retains information for limited durations. Specifically recent episodic events are the first memories to vacate the mind. Ginkgo as described in our text book is a possible homeopathic herb that is supposedly a mild preventative to memory deteriorating disease.
Our textbook by Linifield mildly acknowledges that is remarkably popular but it indeed does not show significant improvement. If ginkgo does help improve the memory it is slight or extremely small. But despite the lack of scientific evidence a large percentage of Americans still ingest ginko.
According to the following youtube link the results from ingesting ginkgo are larger than the book describes, but still basically useless for most middle aged and young people. I can see the benefits of a homeopathic memory enhancer such as ginkgo and I'm sure that the placebo effect comes into play here. With any homeopathic drug much of the success could be due to the placebo effect.
Even though the results are slim I feel that taking ginkgo at the onset of a senile memory deteriorating disease would still be helpful.