Mental Imagery Flashcards
Mental Imagery
invention/recreation of experience resembling the experience of actual object or an event, either w/ or w/out direct sensory stimulation
Behavioral evidence
Imagined interactions w/ imagined stimuli can resemble actual interactions w/ actual stimuli
Cognitive neuroscience
Similar areas of the brain are activated during imagining and perception
Mental Rotation Exp.
- Behavioral evidence
- (1) Stimuli = letters (F, R)
IV: Angle of rotation from upright (450 increments)
IV: Normal or Reversed - Task: Normal or Reversed?
- DV: RT for correct responses
- 2) Stimuli = object pairs
IV: Angular disparity b/t objects
IV: Rotation in picture-plane(roate clock/counter) vs. depth (rotate in2 slide)
Task: objects identical/different?
DV: RT for correct “identical” trials
- Positive linear relationship btwn angular disparity & RT
- mental rotation analogous to physical rotation
Mental scanning
Map Exp
- behavioral evidence
- Ps studied map of island until they had memorized all landmarks (7)
- Map removed from sight
- Imagery task: “Focus on the snack shack. How many trees on the outside? Focus on the boathouse. How many windows?”
- Results: Time taken to answer Q about 2nd landmark pos. correlated w/ distance from 1st
Visual & verbal imagery vs. perception Exp.
- bahavioral evidence
Visual Imagery Task:
- Ps looked at image
- Drew it from memory
- Imagery task: Moving clockwise from where * appeared, corners extreme top/bottom (Y) or not (N)?
Verbal Imagery Task
- Listen to sentence “A bird in the hand is not in the bush”
- Repeat it from memory
- For each word: Noun (Y) or not (N)?
interference was spatial in nature – due to conflicting direction in which Ps had to scan mental image and physical array
Visual & verbal imagery vs. perception
Dual Task Methodology
- Tasks that use similar mental “resources” should interfere w/ each other
- If scanning imagined stimulus (F) uses visuo-motor resources (like perception), should see more interference when output task also requires visuo-motor resources.
fMRI data w/ mental imaging
- Parietal activation during mental rotation
- Temporal activation when imagining object properties (size, shape, color)
- Fusiform Face Area – faces
- Parahippocampal Place Area– scenes (landscapes, cityscapes, rooms)
- *Perception** trials: Ps viewed pics of famous faces/familiar places
- *Imagery** trials: Ps heard names of faces/places, and instructed to form mental image of it
fMRI findings for FFA and PPA
FFA
More activation when imagined faces than places
PPA
More activation when imagined places than faces
fMRI Snail Duck Exp
- Ps asked to identify object during brief presentation of “reversible figure”
- After removed, Ps asked to find 2nd interpretation
- Found 2nd only when given opportunity to draw original pictured object (or when given clues)
Differences btwn imaging and percieving
- fMRI: Weaker activation of relevant brain areas during imagery
- Reversible figures: It is more difficult to reinterpret a mental image
