Chapter 10 - Visual Imagery

Question 1

Visual Imagery

Answer 1

Seeing in the absence of a visual stimulus.

Question 2

Mental Imagery

Answer 2

A broader term that refers to the ability to re-create the sensory world in the absence of physical stimuli, is used to include all the senses. Like when we imagine tastes, smells, and tactile experiences.

Question 3

What does imagery do?

Answer 3

Can provide a way of thinking that adds another dimension to the verbal techniques usually associated with thinking.

Question 4

What did Wundt propose about imagery?

Answer 4

• Images were one of the three basic elements of consciousness, along with sensations and feelings.
• Also proposed that because images accompany thought, studying images was a way of studying thinking.

Question 5

Imageless Thought Debate

Answer 5

A debate where people either think thought is impossible without image or possible without image.

Question 6

What are Galton’s arguments for the imageless thought debate?

Answer 6

• He found evidence supporting the idea that imagery was not required for thinking.
• He came to this conclusion by observing the fact that people who had difficulty forming visual images were still capable of thinking.

Question 7

What is the paired-associate learning experiment?

Answer 7

An experiment where participants are presented with pairs of words, like boat-hat or car-house. They are then presented with the first word of each pair.

Their task is to recall the word that was paired with it during the study period. Thus, if they were presented with the word boat, the correct response would be hat.

This showed Paivio that it is easier to remember concrete nouns, like trunk than it is to rememeber abstract nouns, like justice, that are difficult to image.

This is why he proposed the conceptual peg hypothesis.

Question 8

What is the conceptual peg hypothesis?

Answer 8

Hypothesis stating that concrete nouns create images that other words can “hang onto”. Helps jog our memory to see the image.

Question 9

Mental Chronometry

Answer 9

Determining the amount of time needed to carry out various cognitive tasks.

Question 10

Shepard and Metzler Experiment and Findings

Answer 10

• Inferred cognitive processes by using mental chronometry.
• Used the mental rotation experiment.
• What was important about this experiment was that it was one of the first to apply quantitative methods to the study of imagery and to suggest that imagery and perception may share the same mechanisms.

Question 11

Stephen Kosslyn First Mental Scanning Experiments

Answer 11

• Participants were asked to memorize a picture of an object, such as a boat.
• Then they had to create an image of that object in their mind, and to focus on one part of the boat, such as the anchor.
• Then they were asked to look for another part of the boat, such as the motor, and to press the “true” button when they found this part or the “false” button when they couldn’t find it.
• Kosslyn reasoned that if imagery, like perception, is spatial, then it should take longer for participants to find parts that are located farther from the initial point of focus because they would be scanning across the image.
• This is what actually happened, and Kosslyn took this evidence for the spatial nature of imagery.

Question 12

What discredited Kosslyn’s first mental scanning experiment?

Answer 12

Glen Lea proposed that as participants scanned, they may have encountered other interesting parts of the image and this decreased their reaction time.

Question 13

How did Kosslyn and coworkers conduct their second experiment?

Answer 13

• Asked people to imagine three to seven places on an island and imagine the trips between these places.
• Kosslyn determined the relationship between reaction time and distance shown - like in the boat experiment, it took longer to scan between greater distances on the image, a result that supports the idea that visual imagery is spatial in nature.

Question 14

Imagery Debate

Answer 14

A debate about whether imagery is based on spatial mechanisms, such as those involved in perception, or on mechanisms related to language, called propositional mechanisms.

Question 15

Spatial Representations

Answer 15

Representations in which different parts of an image can be described as corresponding to specific locations in space.

Question 16

How did Pylynshin disagree with Kosslyn?

Answer 16

• Stated that just because we experience imagery as spatial does not mean that the underlying representation is spatial.
• Argues an epiphenomenon, since we don’t know what’s going on in our mind.

Question 17

Epiphenomenon?

Answer 17

Something that accompanies the real mechanism but is not actually part of the mechanism.

Question 18

What did Pylynshin propose?

Answer 18

• Propositional representations: Representations in which relationships can be represented by abstract symbols, such as equations or statements.
• This would involve a spatial layout showing a representation in a picture.
• Depictive representations: Spatial representations such as the picture of a cat under the table in which parts of the representation correspond to parts of the object.

Question 19

Explain the size in the visual field experiment and the reason behind it.

Answer 19

• Essentially if something is further away it is harder to see small details of the image, but as you move closer you start seeing these details.
• Kosslyn wanted to determine if the relationship between the distance of an image and the ability to perceive details also occurs for mental images.
• Participants had to image an elephant, a bunny, and a fly.
• First, they picture these animals with the elephant taking in more of the visual field. Then asked if the bunny had whiskers.
• Then, they pictured these animals with the bunny taking up more of the visual field beside a fly.
• When the rabbit took up more of the visual field we answered questions about it’s details more quickly than when it was further away.

Question 20

What is a mental walk task and it’s results?

Answer 20

• A task Kosslyn conducted in which participants imagined that they were walking toward their mental image of an animal.
• The task was used to estimate how far away they were from the animal when they began to experience and “overflow” which is when the image fills the visual field.
• Results show that we had to move closer for smaller animals than bigger animals.
• This result provides further evidence for the idea that images are spatial, just like perception.

Question 21

What did Cheves Perky experiment show?

Answer 21

• Wanted to have a demonstration between perception and imagery.
• Perky asked her participants to “project” visual images of common objects onto a screen and then to describe these images.
• Perky was projecting a very dim image and the participants described the images as dim even though they didn’t know they were being shown dimmed images.
• None of the participants noticed that there was a picture on the screen. They had apparently mistaken an actual picture for a mental image.

Question 22

How was Perky’s experiment replicated and what did the results show?

Answer 22

• Replicated by having participants image the letter H or T and then dimly showing them a picture of the letter.
• We saw that when people were imaging the one letter they were more likely to see it on the screen.
• This was interpreted as perception and imagery sharing some mechanisms.

Question 23

Imagery Neurons

Answer 23

• Neurons that fire both when a stimulus is perceived and imagined.
• Important discovery as it demonstrates possible physiological mechanisms for imagery and because these neurons respond in the same way to perceiving an object and to imagining it, thereby supporting the idea of a close relation between perception and imagery.

Question 24

How was brain imaging used to demonstrate a relation between imagery and perception?

Answer 24

• Found that both perception and imagery activate the visual cortex.
• Activity increased both when a person observed presentation of a real stimuli (perception) and when they imagined it (imagery).

Question 25

Topographic Map

Answer 25

• The way the visual cortex is organized.
• Specific locations on a visual stimulus cause activity at specific locations in the visual cortex, and points next to each other on the stimulus cause activity at locations next to each other on the cortex.
• Research shows small object causes activity in the back of the visual cortex and large objects causes activity near the front of the visual cortex.

Question 26

What research did Kosslyn conduct using the topographic map?

Answer 26

• Wanted to know what would happen if participants created mental images of different sizes.
• Had participants create different-sized images and observe where activation was occurring in the visual cortex.
• Discovered both imagery and perception result in topographically organized brain activation.

Question 27

Was there any evidence of fMRI overlap in the brain for perception and imagery?

Answer 27

• fMRI showed that there is almost complete overlap of the activation caused by perception and imagery in the front of the brain, ut some difference near the back of the brain

Question 28

How is MVPA used to study the relation between perception and imagery?

Answer 28

• Had people imagine and perceive things.
• It was better at determining imagery than perception.

Question 29

How was TMS used to measure imagery and perception?

Answer 29

• Had people look at patterns to perceive and then imagine these patterns to discover imagery.
• Reaction time was measured.
• The results indicated that stimulation caused participants to respond more slowly and that this slowing effect occurred both for perception and imagery.
• We can conclude that brain activity in the visual cortex plays a causal role in both perception and imagery.

Question 30

Patient M.G.S.

Answer 30

Removed: Right occipital lobe.

Before Surgery: Mental Walk Task showed that she could be about 15 feet before image overflow.

After Surgery: Distance of Mental Walk Task increased to 35 feet.

Demonstrates: Removing parts of the visual cortex reduced the size of her field of view. This supports the idea that the visual cortex is important for imagery.

Question 30

Unilateral Neglect

Answer 30

• Caused by damage to the parietal lobe.
• Patient ignores objects in one half of the visual field, even to the extent of shaving off half of a face in an image.

Question 31

Patient R.M.

Answer 31

• Damage to his occipital and parietal lobes.
• Could recognize objects to draw accurate pictures of objects that were placed before him.
• Could not draw objects from memory (imagery task).
• Trouble answering questions like “an apple is smaller than a grapefruit” as they depend on imagery.
• Shows a dissociation from “normal” people.

Question 32

Patient C.K.

Answer 32

• Suffered from visual agnosia which is the inability to visually recognize objects.
• Could recognize parts of objects but couldn’t integrate them into a meaningful whole.
• Could draw objects from memory a task that involves imagery.

Question 33

What did the dissociation between Patient R.M. and Patient C.K. show us?

Answer 33

• The neurophysiological overlap between imagery and perception is only partial.

Question 34

What is the conclusion from the Imagery Debate?

Answer 34

• Most have come to the conclusion that imagery and perception are closely related and share some, but not all, mechanisms.

Question 35

Method of Loci

Answer 35

• A method in which things to be remembered are placed at different locations in a mental image of a spatial layout.
• Placing images at locations can help in retrieving the memories later.

Question 36

Pegword Technique

Answer 36

• Involves imagery, but instead of visualizing items we associate them with concrete words.
• Often used as the basis behind books that claim to provide the key to improving your memory.

Question 37

Kozhevnikov’s different degress of vividness experiment.

Answer 37

• Wanted to understand to what degree the degree of vividness between people’s mental images.
• Conducted a questionnaire where people had to solve problems and then indicate how they solved them - either using verbal or imagery logic.
• Visualizers then had to be measured using two types of imagery: spatial imagery, the ability to image spatial relations like the layout of a garden, and object imagery, the ability to image visual details, features, or objects like a rose bush with bright roses.
• They completed these two tasks and it was determined that people with people with high object imagery had low spatial imagery and vice versa.
• Spatial imagers did better in the mental rotation task and object imagers did better on the degraded pictures task, thus providing more evidence distinguishing between spatial and object imagers.

Question 38

What are Francis Galton’s criteria for mental imagery?

Answer 38

1. Illumination: Is the image clear or dim? How is the brightness compared to an actual scene?
2. DEfinition: Are all the objects well defined at the same time, or is the place of the sharpest definition at any moment more contracted than it is in a real scene?
3. Colouring: Are the colours of the image distinct and natural?

Question 39

What are the differences between the experience of image and perception?

Answer 39

• Perception is automatic and stable.
• Imagery takes effort and is fragile.