Mental imagery Flashcards
Imagery and Perception: explain Kosslyn (1973) - Boat and Kosslyn (1978) - Island
- Asked participants to memorize a boat
- asked participants to focus on one part of the boat and then mentally move to another.
- Results: increased RT when they had to scan for larger distances.
- Told participants to imagine and island with 7 locations
- There were no distractors
- Obtained the same results as in the first experiment –> increased RT for increased distances
Explain Kosslyn (1978) - Animals
- Imagine 2 animals. 1 small and 1 big.
- Zoom in until the larger animal fills the visual field.
- Asked participants to answer questions about the same animal when it was larger in comparison to the other animal and when it was smaller in comparison to the other animal.
- Participants answered better when the animal was big.
- “Mental walk” –> walk closer to the animal to look at the details –> decreased RT when you are closer
What is the imagery debate?
Is imagery spatial or propositional?
- Spatial
- Propositional –> knowledge of how things relate to each other –> Pylyshyn (1973) –> we use abstract knowledge to answer questions. He didn’t say that visual imagery doesn’t exist but that it is not the cause.
Explain Perky (1910) - projection
- Projected faint images, participants imagined the same objects
- Participants didn’t know that projected images were there
Actual images and visual stimuli seem confusable/similar
Explain Farah (1985) - H or T
- Participants imagined an H or a T
- Then they got an H or a T
- They performed better if both matched
What are the differences between perception and imagery?
- Perception is automatic and stable
- Imagery is effortful and fragile
Chalmers and Reisberg (1985)
- Participants created mental images of ambiguous figures
- Result: Harder to ‘flip’ imaged vs perceived ambiguous figures
What is the relationship between imagery and the brain?
Kreiman et al (2000)
- found that there are individual neurons that activate when you see or imagine a specific stimulus.
Le Bihan et al (1993) - fMRI study
- Real and imagined stimuli activate the same brain areas
Ganis et al (2004) - fMRI
- Found differences between perception and mental imagery
- Similar activations for the front of the brain but not for the back (occipital lobe)
- The visual cortex is in the occipital lobe, and there was more activation of it with visual stimuli than with imagined
Amedi et al (2005) - fMRI
- Similar activation for imagined and perceived
- Imagined activated more areas of the brain –> because it’s more difficult to imagine?
Explain Kosslyn (1999) - TMS
- Used TMS to deactivate visual areas of the brain
- This impaired perception and imagery task
- When unrelated areas were deactivated there was no impairment in tasks
- They established a causal relationship
What is the model in neuropsychology perception and imagery?
Behrmann et al
- Conflicted evidence of overlap between imagery and visual perception.
- Visual perception –> lower visual processing (bottom-up)
- Mental imagery –> top-down process; uses higher visual areas.
- Use to explain some cases. CK lower visual damage –> problems with visual perception
RM higher level damage –> problems with mental imagery
What is mental imagery?
Experiencing a sensory impression without sensory input. It can come in many different modalities (taste, hearing, etc)
What is visual imagery?
- It’s the most commonly researched form of mental imagery.
- Seeing in the absence of a visual stimulus.
- A form of cognition
- Important for creative breakthroughs (e.g., Kekule and the structure of benzene or Einstein and the theory of relativity)
What were Wundt’s early ideas about imagery?
- 3 basic elements of consciousness: sensations, feelings, and images.
Explain the imageless thought debate.
Aristotle claimed that there could be no thought without images. –> though = label for images
Galton notes that people with bad visual imagery could think just fine.
It’s an unresolved debate
Imagery and the cognitive revolution: explain Paivio’s early cognitive paradigm.
- Study using word pairs.
- Used concrete vs abstract words.
- Better memory for concrete words
- Conclusion: associating images with words improves memory.
- Led to the conceptual peg hypothesis –> concrete words allow the forming of visual images that other words can hold on to
Imagery and the cognitive revolution: explain Shepard and Meltzer’s 1971 experiment.
- Mental rotation
- They varied the angle of the comparison shape, and they measured the response RT
- Results: increased RT as the angle of rotation increases.