Cognitive Psychology Chapter 10 Visual Imagery

Visual Imagery

"Seeing" in the absence of a visual stimulus

Pegword Technique

-Associate items to be remembered with concrete words -Pair each of these with a pegword -Create a vivid image of things to be remembered with the object represented by the word

Paired-associate learning

2 unilateral words. Participants had to remember two words together by visualizing or just repetition. For example, tree and boat.

Perky

Banana

Transcranial Magnetic Stimulation

Deactivate portion of the brain for a small amount of time.

Mental Imagery

Experiencing a sensory impression in the absence of sensory input

Category-Specific Neurons

Found neurons that respond to some objects but not others. For example, neuron responds to picture of a baseball but not a face. Imagery neurons respond to both perceiving and imagining an object which shows an overlay in brain activation at the visual cortex.

What debate began regarding imagery?

Is imagery spatial or propositional?

Imageless-thought debate

Is thinking possible without images? Dominance of behaviorism

Pylyshyn (2003)

Kosslyn's results can be explained by using real-world knowledge unconsciously (i.e., tactic-knowledge explanation). For example, you don't have to picture a map to know that Montana further away from Michigan than Ohio is.

Paivio (1963, 1965)

Memory for words that evoke mental images is better than those that do not (concrete vs abstract words ... tree vs freedom). Easier to remember the word tree because it is a concrete word. Developed the conceptual-peg hypothesis

Tactic-Knowledge Explanation

Participants unconsciously use knowledge about the world in making their judgments.

Differences in experience

Perception is automatic and stable Imagery takes effort and is fragile (people will close eyes or look up to block out external factors)

Spatial Representation

Pictures (forming a picture in your mind). Also known as depictive representation.

Method of loci

Placing images at locations Visualizing items to be remembered in different locations in a mental image of a spatial layout (Ex: no grocery list so imagine the items around your home)

Kosslyn interpreted the results of his research on imagery (such as the island experiment) as supporting the idea that the mechanism responsible for imagery involves __________________ representations.

Spatial

Chalmers and Reisberg (1985)

Task: Had participants create mental images of ambiguous figures. Result: Difficult to flip from one perception to another while holding a mental image of it. (Duck/Rabbit Experiment)

Imagery debate

There was a debate between whether imagery was spatial or proposition.

Shepard and Meltzer (1971)

Used mental chronometers (first to apply quantitative methods to the study of imagery and to suggest that imagery and perception may share the same mechanism). He ran an experiment in which participants mentally rotated one object to see if it matched another object. Found a linear relationship: the more times the object was turned, the longer it took to say Yes or No about whether it was the same object.

Mental-walk Task

We move closer to small animals than to large animals even when imagining. Images are spatial like perception.

Mental Scanning

participants create mental images and then scan them in their minds. We act as if our mental images are physical entities. This supports that there is spatial correspondence between imagery and perception.

Proposition Representation

symbols, language (example: on, above, under)

Using imagery to improve memory

-Visualizing interacting images (bizareness not necessary) -Method of loci -Pegword Technique

Conceptual-peg hypothesis

Abstract words can hang on concrete words. Concrete nouns create images that other words can hang onto.

Lea (1975)

An increase in distractions when scanning between longer distances may have led to an increased amount of reaction time.

Unilateral Neglect

Caused by damage to the parietal lobe. Patient ignores objects in one half of visual field in perception and imagery. For example, some patients will shave just one side their faces, or eat the food only on one side of the plate.

LeBihan et al. (1993)

Found that there is an overlap in brain activation at the visual cortex. Both perception and mental imagery activate the visual cortex.

Finke and Pinker (1982)

Had participants judge whether arrow points to dots previously seen. Result: Longer reaction time when greater distance between arrow and dot (as if they were mentally traveling). Not instructed to use visual imagery, no time to memorize so NO TACTIC KNOWLEDGE used

Kosslyn (1978)

Had participants study figure of island with 7 locations, 21 trips. The results show that it took longer to scan between greater distances. The implication of this study was that visual imagery is indeed spatial.

Farah

Letters Stated tactic knowledge could be being used during the mental walk task because you know from experience that you have to walk closer to a mouse for details than to an elephant.

What was a way that was developed to measure behavior and could that could be used to infer cognitive processes?

Paired-associate learning

Kosslyn (1973)

Participants were told to memorize picture, create an image of it. In the iimage, move from one part of the picture to another. The results showed that it took longer for participants to mentally move a long distance that shorter distances. The implication from this study was that like perception, imagery is spatial.

Why is visual imagery useful?

Provides a way of thinking that adds another dimension to purely verbal techniques

Pylyshyn (1973)

Said that spatial representation is an epiphenomenon. As in, it accompanies the real mechanism but is not actually a part of it. Proposed that imagery is propositional (it can be represented by abstract symbols, verbal, idea unit).

M.G.S.

She had the removal of her visula cortex which resulted in reduced visual field and increased distance for when visual field is overflowed. Shows that visual cortex is important for imagery.

Kosslyn (1978) - comparing imagery and perception

This study was to show the relationship between viewing distance and ability to perceive details. Asked participants to imagine a small animal next to a large animal. Quicker to detect details on the larger animal when it covers up most of the visual field.