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Answer to #1
The key idea underlying image scanning research is that images can be scanned in much the same way as physical percepts can be scanned. Furthermore, our strategies and responses for imaginal scanning should be the same as for perceptual scanning.
A means of testing the functional equivalence of imaginal scanning is to observe some aspects of performance during perceptual scanning, and then compare that performance with performance during imaginal scanning. For example, in perception, scanning across longer distances takes longer than scanning across shorter ones. The same finding holds when scanning images. There is an almost-perfect linear relation between the distances separating pairs of objects in the mental map and the amount of time it takes to scan them.
Answer to #2
In spatial neglect, a person ignores half of his or her visual field. In representational neglect, a person asked to imagine a scene and then describe it ignores half of the imagined scene. Although these two types of neglect often occur together, they can also occur independently.
Answer to #3
Mental models are knowledge structures that individuals construct to understand and explain their experiences. The models are constrained by the individuals' implicit theories about these experiences, which can be more or less accurate. Johnson-Laird also hypothesized that individuals use propositions, which he conceptualized as fully-abstracted representations of verbally expressible; and that they use images.
Answer to #4
Mental rotation involves rotationally transforming an object's visual mental image (Takano & Okubo, 2003; Zacks, 2008). Just like you can physically rotate a water bottle you hold in your hands, you can also imagine a water bottle in your mind and rotate it in the mind.
Current brain-imaging techniques have allowed researchers to create images of human brain activity noninvasively to address such speculations. For example, in a study using fMRI, investigators found that the same brain areas involved in perception also are involved in mental rotation tasks. In one study, participants physically rotated objects instead of merely watching them being rotated. Later, they imagined the rotation of these objects. Parts of their motor cortex were activated that normally would not have been activated during mental rotation. In other words, the prior physical rotation of the objects affected the way their brains later processed the mental rotations of images of those objects. Of particular importance is the early visual cortex. It is the first area that receives input from the retina when we see an object. The early visual cortex (in particular, areas 17 and 18) is activated during imagery. Furthermore, when area 17 is impaired by means of transcranial magnetic stimulation (TMS), imagery is compromised as well. In mental rotation, the primary motor cortex is activated when participants imagine manually rotating a stimulus (but not when they imagine a rotation driven by an electric motor). Thus, not only are imagery and perception functionally equivalent in many psychological studies, neuropsychological techniques also verify this equivalence by demonstrating overlapping brain activity.
Answer to #5
According to dual-code theory, we use both pictorial and verbal codes for representing information in our minds. These two codes organize information into knowledge that can be acted on, stored somehow, and later retrieved for subsequent use. According to Paivio, mental images are analog codes. Analog codes resemble the objects they are representing. For example, trees and rivers might be represented by analog codes. Just as the movements of the hands on an analog clock are analogous to the passage of time, the mental images we form in our minds are analogous to the physical stimuli we observe. In contrast, our mental representations for words chiefly are represented in a symbolic code. A symbolic code is a form of knowledge representation that has been chosen arbitrarily to stand for something that does not perceptually resemble what is being rep- resented. Just as a digital watch uses arbitrary symbols (typically, numerals) to represent the passage of time, our minds use arbitrary symbols (words and combinations of words) to represent many ideas.
Answer to #6
Declarative knowledge refers to facts that can be stated, such as the date of your birth, the name of your best friend, or the way a rabbit looks. Procedural knowledge refers to knowledge of procedures that can be implemented. Examples are the steps involved in tying your shoelaces, adding a column of numbers, or driving a car. The distinction is between knowing that and knowing how.
Answer to #7
According to the functional equivalence hypothesis, although visual imagery is not identical to visual perception, it is functionally equivalent to it. Functionally equivalent things are strongly analogous to each otherthey can accomplish the same goals. The functionally equivalent images are thus analogous to the physical percepts they represent. This view essentially suggests that we use images rather than propositions in knowledge representation for concrete objects that can be pictured in the mind.
Evidence for functional equivalence can be found in neuroimaging studies. In one study, for example, participants either viewed or imagined an image. Activation of similar brain areas was noted, in particular, in the frontal and parietal regions. Additionally, imagery can evoke responses in high-level visual brain areas and the visual primary cortexareas that are highly involved in the processing of visual stimuli we see with our eyes.
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