We learn a lot by watching and then imitating the actions of others. An important part of that learning involves imitation of gestures and hand movements. Although we may take this ability for granted, it is actually very difficult. It can put a tremendous load on short term memory, and some people are far, far better at this than others. To test your gestural memory, view one of the movies linked below, then try to imitate the gestural sequence in the movie. Each movie begins by displaying a hand whose fingers are all fully extended. After that, the hand makes a series of gestures, usually changing the flexion of one or two fingers at a time. Incidentally, these minimal changes per gesture will be used to connect people's performance errors to the neural mechanisms in the brain's cerebral cortex that control various finger movements. In the Visual Cognition Laboratory at Brandeis University, we have developed automated tools to measure how well or how poorly any person does at this task. With the web demonstrations below, though, you'll have to check your own performance --by re-playing a movie right after you've finished imitating what you saw and then scoring yourself.If you get some of your friends to try some of these demonstration tests, you will see just what we mean we say that there are large differences among people in gestural memory. And if you find the task difficult at first, don't give up. As in so many things in life, practice makes (nearly) perfect.