Gilles Deleuze believes that our brain has two modes of functionning: action and reflexion, and that these 2 modes are mirrored in cinema. He calls them “movement image” and “time image”.
“Movement image” is the most traditional in cinema: the camera follows a character and the point of view changes in response the character’s actions. “Movement image” follows the principle of action-reaction and abides to rationality: the camera reacts to the character’s action in a way that is predictable, so that the audience knows what to expect. For example, somebody walks out of a room. When this person crosses the door threshold, the camera stops filming towards the inside of the room (now empty) and instead films the character now walking outside.
In “time image”, the length of the shots is not determined by the action taking place. Deleuze calls this “a purely optical and sonorous situation”. For example, a long shot on 2 characters fishing and not talking. Since nothing is said, the only information to be gathered by the viewer is that the characters are fishing, and this would require only a very short sequence to be communicated. The time after which the shot ends is arbitrary since no specific action by the characters cause the shot to end, and, if the shot had continued longer, nothing more would have happened (the characters would still be fishing in silent). In “image time”, the next shot is also unrelated to the previous one. For example, a shot of one of the characters going on an undescript errand in town. The new action the character is doing is not caused by the previous action (fishing) and therefore the viewer is unable to determine when it is taking place compared to the first one. The errand could take place just after, long after or even in the past compared to the fishing.
Deleuze place the apparition of the “time image” in cinema after the second world war. He thinks that the war was such a complex and unprecedented events that is escaped people’s understanding, and therefore shattered their ability to plan rational actions responding to events. The traumatic event, too big for human understanding, broke the chain of action-reaction. Unsettled, the characters of a time image find themselves unable or unwilling to act. Instead, they become witnesses of “a pure moment of time”.
Because the logical chronology of actions is broken by the “time image”, Deleuze believes that “the cinema image is not in the present”. Rather, cinema images show different layers of memories whose meanings sometimes converge towards the present.
Just as human beings constantly alternate between action and reflexion, it is possible to mix “movement images” and “time images”. Let’s take the same example of a man going out of a room. The camera shows him walking out but rather than cutting just after he crosses the threshold, it keeps showing the empty room for a bit before switching to the man outside. This confuses the viewer: why is the camera still showing the empty room ? The viewer starts wondering whether there is something in the room that he is not noticing or understanding. Is there a hidden threat in the room ? The camera follows follows the man going out and cut shortly after he is gone so there is action-reaction, but is perverted by the unexplained pause to look at the empty room: the timing of the reaction is not correct. Additionally, when the camera stops showing the empty room, it may not show the man now outside, but switch to something completely different. In that case, not only is the timing of the reaction wrong, but the reaction itself is not logical. The presence of action reaction but the absence of correct timing and/or logical sequences of events unsettle the viewer: it gives them the feeling that they are confronted with a sequence of events whose logic they cannot understand. Therefore, this sequence of events is perceived as threatening however ordinary each individual event might be. This process is often used by David Lynch: a noise or flash suggesting sudden action is shown, then an empty room is shown so that the viewer wonders “could the sudden event be happening right now behind my back ?” Often also, a phone is shown ringing and nobody picks it up. Later in the film, someone may be shown picking up the same phone up, so that the chronology of all events shown in between the 2 shots involving the phone become unclear. Or, if someone picks the phone up straight away, the camera stays on the phone and does not show the person apart from a glimpse of their hand.