The Use of Iambic Pentameter in the

from bottom-up processing with prior knowledge about the visual world (e.g.,
Biederman, 1987; Peterson, 1994; Shepard, 1983). The modification of bottom-up
information by application of prior knowledge is considered to be a top-down process.
One type of top-down processing is the use of context for image identification.
When humans are familiar with the context of an image, they are often able to recognize
this image at a faster rate (e.g., Palmer, 1975). For example, a neighbor outside her house
might be recognized more quickly than if she were in a shopping mall. When seeing a
neighbor in her house, humans apply what we know about who lives in that house to
determine who is there. It is very easy to make this determination, even if our neighbor
appears far away, because the object person is in a context where we often see her.
However, when a neighbor is spotted in an alternative location, she may be more difficult
to discern without the familiar context. A second example of the influence of context is
the word superiority effect (Reicher, 1969; Wheeler, 1970). A target letter is identified
more rapidly when primed within a word than when primed independently. In this case,
the context word prime allows humans to more quickly interpret object letters when it is
present. Without the primed word context, letters are less quickly identified.
The use of familiar context is not the only way that knowledge can influence what
humans visually perceive. Another factor to consider is the schemata that humans have
about particular spatial scenes. A schema is a pattern of knowledge that describes what is
typical in a particular situation (Reisberg, 2001). We interpret objects in scenes according
to the schema that we have about those scenes. For example, an office schema would
specify that a desk and a chair would likely be present whereas a refrigerator and an oven
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