Chapter 2: The Perceptual Cycle

Neisser’s (1976) perceptual cycle is conceptualized as a framework because it “is not intended as a radical alternative to the classical theories but as a way to render them coherent with one another and everyday reality” (p. 24). In other words, it places a group of theories into a cohesive framework. The perceptual cycle, which is shown in Figure 1, is described here because it is the foundation of the HuWI cycle.

Figure 1. Neisser’s (1976) perceptual cycle, where the schema directs exploration, which samples the object, which modifies the schema.

Overview

Figure 1 depicts Neisser’s (1976) perceptual cycle. The cycle shows the reciprocal relationship of the schema (i.e., knowledge about the environment) directing exploration of the environment (i.e., action), which samples the information available for pick up in the environment, which then modifies the schema, and so on. This cycle is useful for describing how knowledge, perception, action, and the environment all interact in order to achieve goals.

For example, if one intends to exit a living room that has four doors, then how does one go about achieving this goal? According to the perceptual cycle, they will need to use their schemata, exploration, and the environment. The following sections describe what happens at each stage of the cycle in more detail. We begin, however, with a discussion of goals, since the perceiver’s intentions are what set the cycle in motion.

The Influence of Goals

As can be seen in Figure 1, there is no explicit representation of intent or goal. However, Neisser (1976) does state that “one must know another person’s schemata and intentions to know what he will do” (p. 186; emphasis added). In this system, intent, or having a goal, is a higher cognitive process that is used to select the appropriate schema for a given situation. Returning to the example of leaving the living room, it would be inappropriate to select a schema of one’s bathroom in order to exit the living room. More will be said about this and other contributions of goals within the perceptual cycle in subsequent sections.

Schemata Direct Exploration

According to Neisser’s (1976) perceptual cycle, people have anticipatory schemata that direct exploratory actions. The schema is a structured pattern of knowledge, which serves two purposes. First, it prepares the perceiver to accept information that will modify the schema. For example, if one intends to exit an unfamiliar room that has four doors, then they could invoke a general “room schema.” This “global” schema probably has information about common characteristics of rooms like the presence of walls, a floor, a ceiling, and an exit. These characteristics are what the perceiver anticipates encountering within the room. With this anticipatory schema invoked, she is now ready to accept certain kinds of information, like the locations of the doors. Once picked up, this information modifies her schema, thus making it specific to that room and again ready to accept other information (e.g., what is behind each door).

The second purpose of the schema is to direct action. For example, if one knows that a door is blocked by a brick wall, then, because one anticipates the wall, there is no need to spend time exploring the possibility of traversing that route. This component of the cycle, therefore, posits that complex mechanisms in the brain are involved in perception, making it compatible with theories of perception which propose that perception results from perceptual set and hypothesis-testing (e.g., Gregory 1974, 1980).

Exploration Samples Available Information in the Environment

The next component of the perceptual cycle is exploration that samples information available in the environment. For example, in vision, the optic array (i.e., a structured arrangement of ambient light at a point of observation; Gibson, 1970) provides information about the environment that the observer picks up or samples. Motion, therefore, provides valuable information for the observer. A moving point of observation (action) changes the available information (e.g., revealing a brick wall that was occluded by a protruding door jam), therefore generating even more information about the environment for the observer to sample. This component of the cycle is compatible with a direct perception theory of information pick up that posits a reciprocal relation between perception and action, or a perception-action loop (e.g., Gibson 1966, 1979).

Available Information in the Environment Modifies Schemata

The final component of the perceptual cycle is the available information in the environment that modifies the schema, which, as mentioned, accepts this new information. Thus modified, the schema now directs further exploration and so on to complete the cycle. This component describes the truly adaptive nature of behavior. For example, if a passage is blocked by a brick wall, one surely will not continue to try to go through it every time she encounters the passage. In fact, there is no need to continue to look at or explore the blocked path because it is now anticipated by the schema. This component of the cycle, where the initial schema is modified, can also be called accommodation (i.e., modifying a schema to incorporate new information; Piaget, 1952), but not assimilation (i.e., modifying the information that was sampled), which would be inconsistent with the direct-perception stance taken by Neisser (1976).

Neisser’s (1976) perceptual cycle has been used by human factors researchers as a framework for understanding constructs such as situation awareness (e.g., Tenney, Adams, Pwe, Huggins, & Rogers, 1992; Smith & Hancock, 1995). There has been mention also of the cycle as being useful for understanding human-computer interaction in general (Dillon, 2003), and even HuWI (Rho, & Gedeon, 1998; Farris, Jones, & Elgin, 2002). The latter discussions, however, did not fully specify how the cycle relates to human-computer interaction or HuWI. The following section, therefore, provides a detailed explanation of the perceptual cycle applied to HuWI.

Document Last Updated December 31 1969 19:00:00.