Deictic cues and the power of the gaze

In document An attentional theory of continuity editing (Page 60-64)

Chapter 3: Hiding a Cut

3.2 Expecting a visual change

3.2.2 Deictic cues and the power of the gaze

Deictic cues are a subset of associative cues: visual properties of a shot that connect it in some way to the following shot (Gregory, 1961). Associative cues can include environmental factors such as location, lighting, sound effects or even music flowing across the cut. Associative cues tell the viewer that the two shots occur in the same location and at the same time (more on spatiotemporal continuity later, chapter 5). However, some associative cues are actions within the scene that form causal or logical connections between shots. These will be referred to as deictic cues.

Figure 3-4: Two point/glance shots from Blade Runner (Ridley Scott, 1982)

The classic example of a deictic cue is the point/glance shot: a Medium or Full Close-Up depicting an actor’s face looking off screen (Branigan, 1984; see Figure 3-4). The key element of this composition is the actor’s eyeline. The eyeline automatically establishes a question in the mind of the viewer: “What is the actor looking at?”. This leads the viewer to expect the answer to the question in the form of a shot of the target of the actor’s gaze (known as the point/object shot; Branigan, 1984). If the viewer does not know in advance what the character might be looking at they will adopt an attentional set for ‘new objects’. When the new object is then presented their attention will move to it with minimum effort and the validation of their expectation will allow them to logically connect the two shots together. If the space of the scene had already been established and the viewer knew that by looking off screen right the character must have been looking at a particular character, they will expect the next shot to depict that character. If it does then their existing mental representation of the space is reinforced. If the shot depicts something else then their mental representation deteriorates and the viewer will be confused.

60 This ability to use an actor’s gaze to create expectations about what they are looking at and use this to construct cohesive 3D representations of space (see chapter 5 for more details) is not an arbitrary skill learnt specifically for film viewing, it is a key element of human social behaviour. To an observer, another person’s eyes are the most significant part of their body. The eyes will almost always be the first visual feature to be fixated when presented with an image of another human being even if that person is surrounded by a highly detailed background (Yarbus, 1967). This is believed to be due to the important role gaze plays in social interaction (Kleinke, 1986). Gaze has been shown to be used to regulate turn-taking in conversation: express intimacy, and exercise social control (Kleinke, 1986). When involved in a conversation, a listener will predominantly look at the speaker’s eyes and mouth, with only occasional glances to their nose, ears and hair line (Yarbus 1967). When the speaker is addressing another person other than the viewer, the viewer’s eyes will alternate between the eyes of the speaker and listener, looking for signs of the speaker’s intention as well as the listener’s responses (Klin, Jones, Schultz, Volkmar, & Cohen, 2002a). The accurate perception of other people’s gaze is seen as critical to our ability to interpret other people’s intentions, attribute the mental state of ‘seeing’, and structure social interactions (Baron-Cohen, 1995). Without the ability to read gaze these essential social skills disappear. This is most tragically seen in autism (Baron-Cohen, 1995).

This preference for seeking out eyes and following their gaze is developed during the first few months of life (Hood, 1998). The structure of the eye, a white sclera either side of a dark pupil, has been shown to give the human eye a strong salience making it “pop-out” of visual scenes (Bruce & Young, 1998). It has also been shown that the structure of the eye allows the direction of gaze to be perceived very simply and quickly (see Langton, Watt, & Bruce, 2000 for discussion). This prominence is associated with the eyes’ function as a highly effective attentional cue. As was seen in the previous chapter (see section 2.3.3), the speed with which attention shifts to an object can be increased by previously cueing the object (Posner, 1980). These cues usually involve a sudden flash or onset of colour or object at the location being cued.

61 These visual transients capture attention even if the viewer is informed that the cue does not predict the location of the subsequent target (Posner, 1980). These cues can be said to pull attention to an object or location (Langton et al., 2000). By comparison, if the viewer fixates a human face and the cue takes the form of a shift in gaze, the viewer’s attention is pushed towards the target of the gaze (Friesen & Kingstone, 1998; Hood, 1998; Jonides, 1981). Gaze is the only type of cue known to send a viewer’s attention in a particular direction. Cues such as arrows presented at fixation have exogenous effect on attention other than to point in a direction where the viewer might choose to look (Jonides, 1981).

This potential for eyes to first attract, by “popping-out” of the visual scene, and then direct attention is critical for the use of gaze as a deictic cue in editing. If a viewer is fixating the eyes of an actor, when those eyes suddenly shift and point across the screen, the viewer’s attention will be involuntarily pushed in the same direction (Driver et al., 1999; Friesen & Kingstone, 1998). The viewer’s eyes will not move, as there is not yet a target for them to move their eyes to, but their attention will covertly shift in the direction of the gaze. This shift in attention combined with the viewer’s ability to read intentionality into another person’s gaze (Baron-Cohen, 1995) leads the viewer to expect a target for the gaze. The viewer adopts the attentional set of ‘New Object’.

In real-world vision, the viewer would then use their cued attention to either locate an object in the periphery of their vision or move their head to locate an object out of view. They would then perform a saccadic eye movement to the first object they found that aligned with the gaze. In film, the same projection of the gaze through visual space will occur but it will stop as soon as it reaches the screen edge. If the target of the gaze is found within the screen a saccadic eye movement will be initiated (see left column, Figure 3-5). If no valid target exists the editor will have to provide one by cutting to the point/object shot. The object depicted in the point/object shot can either be located along the path of the actor’s gaze, requiring a saccade to fixate (see middle column, Figure 3-5), or be collocated with the viewer’s current point of fixation (see right column, Figure 3-5). In the latter case no saccadic

62 eye movement is required but attention will still be captured by the sudden onset of the expected object. The perceptual consequences of these types of cuts will be discussed in detail later (see chapter 5).

Figure 3-5: Shot pairs (paired top to bottom) occurring across cuts taken from Blade Runner (Ridley Scott, 1982). Two-shots (left column) in which both characters are visible in both shots (the shadow down the side of the frame is the other character; the viewer knows this from the establishing shot). Medium Close-Ups (centre column) with matching eye-lines. Collocated centres of attention (right). Red spots indicate most likely fixation positions in each shot. Red arrows indicate saccadic eye movements between these fixations.

An appreciation of the time taken for a viewer to shift their attention can also be seen in editing insights provided by Dmytryk:

“The viewer, as a rule, will not accept the ‘fact’ of a look until he sees the actor’s eyes focus, or ‘freeze’ on something off-screen. At that point he, too, will look off, following the actor’s gaze. By the time his own eyes have refocused, the actor’s point-of-view (POV) shot should occupy the screen. To make the cut, then, we fix the frame in which the actor’s eyes have ‘frozen’, add three or four frames more to give the viewer time to react and move his eyes as he follows the actor’s look, at which point the cut is made.” (Dmytryk, 1986, page 444)

This three to four frame (125-167ms at 24 frames per second) wait before the cut matches the time taken to perform a saccadic eye movement (average 150-200ms Palmer, 1999). This similarity further reinforces the validity of Dmytryk’s intuition about attentional capture.

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In document An attentional theory of continuity editing (Page 60-64)