Videodrome (1983) IMDb
David Cronenberg (writer-director).
A cable TV operator looking for new programming finds something absorbingly radical.
Obligatory reference point in any and every low-level academic discussion of the effects of moving pictures. To my mind, that slap is one of the weightiest pieces of evidence for the accuracy of ridiculous Freudian-Lacanian psychoanalytic theories of classical cinema, wherein Hollywood succeeds because it presents itself as an expression of the viewer’s own essentially sexual impulses.
References here: Open Your Eyes (1997).