Friends making anxious little jokes about getting Alzheimers. Procedural Memory - tells you how to use a mouse. Episodic memory - will tell you if you have seen the butterfly before.
Episodic memory is the area most likely to worsen with age.
Until recently psychologists have had to infer how memory works. Now technology let us see it - live. He will use all three main kinds of memory in this exercise. Radioactive water is injected into the subject's bloodstream. A subject is first show a series of pictures.