1. The original experiment, from about 1920. It demonstrated that the apparent meaning of a filmed scene derives not from its component images but from what filmmakers call montage: the relation of the images to one another. There’s only one repeated clip of an actor emoting, but montage leads you to interpret the emotion variously as hunger, grief, or lust.
2. From 1922, a new set of shots.
3. Montage: an image appearing to show response. It did help me understand my own response.