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You Know My Name, Look Up the Number
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The third appearance-reality problem invokes higher-order cognitive processes. The first two are perceptual processes: understanding that a
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single object may manifest itself in multiple viewpoints, or that several objects may have (nearly) identical viewpoints. The third problem states
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that objects, although different in presentation, are of the same natural kind. This is an issue in categorization, and it is the most powerful and advanced principle of all. All higher mammals, many lower mammals
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and birds, and even fish, can categorize. Categorization entails treating objects that appear different as of the same kind. A red apple may look different from a green apple, but they are both still apples. My mother and father may look very different, but they are both caregivers, to be trusted in an emergency.
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Adaptive behavior, then, depends on a computational system that can analyze the information available at the sensory surfaces into (1) the invariant properties of the external object or scene, and (2) the momentary circumstances of the manifestation of that object or scene. Leonard Meyer notes that classification is essential to enable composers, performers, and listeners to internalize the norms governing musical relationships, and consequently, to comprehend the implications of patterns, and experience deviations from stylistic norms. Our need to classify, as Shakespeare says in A Midsummer Night’s Dream, is to give “to airy nothing/A local habitation and a name.” Shepard’s characterization recast the categorization problem as an evolutionary/adaptive one. In the meantime, Rosch’s work was beginning to shake up the research community, and dozens of leading cognitive psychologists began to study to challenge her theory. Posner and Keele had
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shown that people store prototypes in memory. In a clever experiment, they created tokens that contained patterns of dots placed in a square— something like the face of dice, but with the dots more or less randomly placed on each face. They called these the prototypes. Then they shifted
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some of the dots a millimeter or so in one random direction or another.
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This created a set of distortions from the prototype—that is, variations—
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