18.5 Context Effects
A given stimulus may trigger radically different perceptions, partly because of our differing perceptual set (FIGURE 18.9), but also because of the immediate context. Some examples:
- When holding a gun, people become more likely to perceive another person as gun-toting—a phenomenon that has led to the shooting of some unarmed people who were actually holding their phone or wallet (Witt & Brockmole, 2012).
- Imagine hearing a noise interrupted by the words “eel is on the wagon.” Likely, you would actually perceive the first word as wheel. Given “eel is on the orange,” you would more likely hear peel. This curious phenomenon suggests that the brain can work backward in time to allow a later stimulus to determine how we perceive an earlier one. The context creates an expectation that, top-down, influences our perception (Grossberg, 1995).
- How is the woman in FIGURE 18.10 feeling?
Figure 18.9
Culture and context effects What is above the woman’s head? In one study, nearly all the East Africans who were questioned said the woman was balancing a metal box or can on her head and that the family was sitting under a tree. Westerners, for whom corners and boxlike architecture were more common, were more likely to perceive the family as being indoors, with the woman sitting under a window. (Adapted from Gregory & Gombrich, 1973.)
Figure 18.10
What emotion is this? (See Figure 18.11.)
RETRIEVAL PRACTICE
- Does perceptual set involve bottom-up or top-down processing? Why?
It involves top-down processing. Our perceptual set influences our interpretation of stimuli based on our experiences, assumptions, and expectations.