The distinction was thought to occur because movies present reflected light ('light on') to the viewer, while a TV picture is back lit ('light through').
The experimenters showed two movies, a documentary and a film with little story line about horses, sequentially to two groups of equivalent size, and had the viewers write a half a page of comments of their reactions.
Although this experiment has validity, it does not deal directly with the central point made by Marshall McLuhan that the cinema image, typically a 35mm frame, is made up of millions of dots, or emulsion, and is much more 'saturated' than the lines and pixels of the TV image.
McLuhan argued that the TV screen invited the audience to 'fill-in' a low-intensity image, much like following the bounding lines of a cartoon.
The high-intensity film image allows for much more information on screen, but also demands a higher degree of visual perception and cognition.