Psy 430
Ch. 7 Perception

Glossary  
Chapter 7  
Afterimage that which arises after looking at a visual stimulus, usually for several seconds. See Positive afterimage; Negative afterimage
Awareness an issue in perception as to whether an individual can respond perceptually to an event in the absence of conscious awareness
Blindsight according to Weiskrantz, the effect of certain kinds of brain damage in which the subject has an inability to recognize objects but retains the ability to detect the presence and movement of objects
Bottom-up processing cognitive processes involving feature extraction that begin with sensory stimulation
Conceptually driven processing see Top-down processing
Converging operations a set of related lines of investigation that all bolster a common conclusion
Data-driven processing see Bottom-up processing
Direct approach to perception Gibson's idea that we directly pick up and use the information afforded by the environment
Double dissociation of function a technique in which opposite behaviors are elicited by two different tasks from different areas of functioning (see Converging operations)
Dynamic perimetry a procedure, used to measure the visual field, in which a small visual target is gradually brought into the field of vision
Emmert's law the size of an afterimage is proportional to the viewing distance
Empirical theory of perception the argument that perceptions are determined entirely by past experience
Hallucination a report of an experience in the absence of any apparent stimulation
Illusion a mistake or distorted perception
Indirect approach to perception the idea that perception results from the interpretation of sensations
Masking the technique of presenting a jumbled visual stimulus immediately after a target stimulus in order to stop the visual persistence of the target
Monitoring task a form of dichotic listening in which observers are not required to verbalize a message as it is presented
Mozart effect the finding that listening to Mozart compositions leads to increased performance on visual-spatial tests
Nativistic theory of perception the theory that genetic "wired-in" mechanisms account for perceptual capabilities (see Empirical theory of perception)
Negative afterimage is opposite in brightness and complementary in color to the visual stimulus (contrast with Positive afterimage)
Objective threshold according to Cheesman and Merikle, the stimulus energy level that elicits truly random behavior (compare with Subjective threshold)
Operationism the position that concepts are defined by the operations used to measure and produce them, but ignores the fact that at least two sets of observations are needed for a complete definition
Perception the awareness process typically viewed as more complex than sensation and usually involving an interpretation of sensation
Perceptual defense an unwillingness to report perceiving unpleasant material, in contrast to an inability to perceive such material
Phenomenological experience a person's awareness of his or her own state of mind
Positive afterimage is similar in brightness and color to the original visual stimulus
Prime sight the after images perceived by patient D.B. to visual stimuli for which he claimed to be blind
Priming facilitation of a response because of a previous experience; e.g., prior presentation of a word speeds later reading of the same word
Scotoma a region of blindness in the visual field caused by a physical defect in the visual system
Sensation the basic and elemental intake of stimulus information
Stroop effect difficulty in naming the color of an object when the color conflicts with the name of the object (when the word blue is printed in red ink)
Subjective threshold the stimulus energy level that yields claims of unawareness but behavior indicating perception of the event (see Objective threshold)
Tachistoscope a device that allows very rapid presentation of visual stimuli
Top-down processing cognitive processes that begin with knowledge of concepts; contrast with Bottom-up processing
Unconscious inference Helmholtz's view that perception involves inferences about sensations and that the observer is unaware of making the inferences
Verbal report a subject's description of his or her phenomenological experience, often very difficult to verify
 

 

1) It has been found that the threshold to identify a letter is lower when that letter appears in a word than when it is presented alone or in a nonword. So, if participants are briefly shown the word bird and then are asked whether there was an r or an l in it, they do so more accurately and at a briefer presentation time than when r is presented alone or in a nonword such as dirb. This is called the word-superiority effect, and McClelland and Rumelhart developed their theory to account for it. See if you can use the information in Figure 7.3 to account for the effect.

 

 

 

5) Consult a perception text and discuss additional examples of illusions and phenomenological reports (eg., moon illusion, ambiguous figures, waterfall illusion).