chapter 10 questions

describe the pioneering studies of shepard and metzler (1971) and kosslyn (1973; 1978)

what fundamental conclusion regarding visual imagery can be drawn from these studies

shepard & metzler

• mental chronometry/rotation

• measured rt of mentally rotating one object to match another

• mean rt were dependent on how much the stimulus had to be rotated

kosslyn

• memorize picture, create an image of it

• participants asked questions requiring them to “travel” through image

• mean rt answer question depended on how far they had to move thru image

conclusion

• imagery is spatial in nature

• spatial representation interpretation of visual imagery states that info is contained in the visual images themselves

describe the criticisms of “spatial representation” model of visual imagery put forth by lea (1975) and pylyshyn (1973)

lea

• the further people had to travel through their visual images, the more distractors they encountered

• distractors caused the increased mean RT not the distance

kosslyn response

• another task with 7 locations on an island and 21 potential trips

• the only thing that mattered was the distance needed to travel through the image, not the distractors

• concluded visual imagery is spatial

pylyshyn

• actual visual image that we experience is an epiphenomenon

• there is no information in visual imagery

• info is represented in symbolic language like a semantic network

• tacit-knowledge explanation

  • results can be explained by using real world knowledge unconsciously

    • we know in real life the farther we must travel, the longer it takes

briefly describe the “propositional” and “tacit-knowledge” interpretations of visual imagery

propositional

• information is represented in symbolic language like in a semantic network

  • symbols, language

tacit-knowledge

• results can be explained by using real world knowledge unconsciously

  • we know in real life the farther we must travel, the longer it takes

how did finke and pinker (1982) counter the “tacit-knowledge” interpretation

• participants judge whether arrow points to dots previously seen

• longer reaction time when greater distance between arrow and dot

• no time to memorize → no tacit knowledge

briefly discuss how studies of relative image size (kosslyn, 1978) and priming (farah, 1985) support the “spatial representation” model of visual imagery

kosslyn

• if imagery and perception are equivalent, we should be faster to answer questions about objects we’re imagining when the object is larger rather than small

  • participants imagine an elephant next to a rabbit or a rabbit next to a fly

  • people were faster to answer if rabbit had whiskers when it was next to a fly (larger)

  • suggests that imagery and perception are roughly equivalent in the brain, both respond to image size in the same way

  • also support spatial representation interpretation of visual imagery

    • if info was represented propositionally, it shouldn’t matter how large the image of the rabbit was

farah

• participants imagined either an H or a T

• two flashes on a scree, either an H or a T

• had to determine which flash contained the letter they were imagining

• performance on this task was better when imagines and presented letter matched

briefly describe neurophysiological evidence supporting the theory that visual perception and visual imagery involve overlapping neural mechanisms

• category specific neurons respond both to perceiving a particular object and imagining that same object

• neural activity to perception and imagery of a baseball and a face

describe neuropsychological evidence supporting the theory that visual perception and visual imagery involve the same neural mechanisms

describe the neurological cases which indicate that there is a double dissociation between visual perception and visual imagery

how can these findings be interpreted so that they are consistent with the conclusions of other neurophysiological and neuropsychological studies

briefly describe methods for improving memory that involve the use of visual imagery