Cog Psych Chapter 10 (Visual Imagery)

What happened in the case of CK where he suffered from visual agnosia?

He couldn't recognize objects Couldn't name an object in front of him but could draw things to accuracy from memory

What was Lea's different explanation to Stephen Kosslyn?

- More distractions when scanning longer distances may have increased reaction time - Interesting things encountered during the mental scan are responsible for these distractions

Unilateral neglect

A syndrome in which people ignore objects located toward their left and the left sides of objects located anywhere; most often caused by damage to the right parietal lobe

Imagery neurons from Kreiman et al (2000)

A type of category-specific neuron that is activated by imagery.

Amedi and coworkers fMRI study found (2005) Why is this?

Again, overlap during imagery Deactivation of non-visual areas of brain Hearing Touch Mental images more fragile, less activation keeps other things from interfering

Kosslyn's (1978) study of size in the visual field with the rabbit and whiskers

Asked subject to imagine an elephant and rabbit standing next to each other, asked does rabbit have whiskers? Did this again but with a rabbit and fly then asked same question Reaction time improved

What is the pegword technique of associating images with words?

Associating items to be remembered with concrete words (peg words) Ex: one/bun, two/shoe

Guariglia and coworkers (1993)

Brain-damaged patient Patient's perceptions intact, but mental images were impaired (unilateral neglect)

Ganis and coworkers (2004) hearing name of object and imagining something with eyes closed experiment found that

Complete overlap of activation by perception and imagery in frontal lobe Differences near back of the brain (occipital lobe)

What happened in the case of RM where there was damage to occipital and parietal lobes?

Could draw accurate pictures of things in front of him, but couldn't draw accurate pictures of things from memory

Shepard and Meltzer's mental chronometry What was their experiment?

Determining the amount of time needed to carry out various cognitive tasks Participants rotated objects mentally

Chalmers and Reisberg (1985) mental images of ambiguous figured test

Had participants create mental images of ambiguous figures Difficult to flip from one perception to another while holding a mental image of it

Kosslyn & coworkers (1999), Transcranial Magnetic Simulation disrupts brain functioning in a certain area for a period of time, when this happens, what did they find?

If behavior is disrupted, the deactivate part of the brain is causing that disrupted behavior

Perky's experiment, in which participants were asked to "project" visual images of common objects onto a screen, showed that

Imagery and perception interact with one another subjects descriptions matched the images Perky projected, they mistaked actual picture for a mental image They didn't realize Perky was projecting a dim projection on the screen

Kosslyn et al answer to Lea study consisted of an island with 21 trips, what did he conclude?

Imagery involved spatial representation, as there is a correlation between reaction time and distance

Stephen Kosslyn used mental scanning tasks, is there a correlation between imagery and perception?

It is supported

What was Paivio's study with paired association learning?

Making two words connect with an associating word "boat and hat" use "captain" as cue to help retrieve next word

Li Bihan et al (1993) What'd they find about overlap in brain activity?

Measured neural activity using an fMRI. They found overlap in brain activity in visual cortex (striate cortex)

What did Paivio find about memory?

Memory for words that evoke mentla images is better than those that do not Memory for concrete nouns that can be imagined is better than memory for abstract nouns that are difficult to imagine

Are imagery and perception automatic/stable or takes effort and fragile?

Perception is automatic and stable Imagery takes effort and is fragile

What is the imagery debate between Pylyshyn and Kosslyn ? Proposition versus depictive?

Proposition: symbols, language Depictive: similar to realistic pictures

What is the relationship between sizes of objects and ability to perceive details?

Quicker to detect details on the larger object

Kreiman et al. (2000) study on perceiving and imagining an object

Record individual neuron responses to perceiving vs. imagining object—same neurons respond

What did Kosslyn and corkers find during the area disruption experiment?

Response time slower to both when area of perception and area of vision are inhibited Brain activity is not an epiphenomenon, brain activity in the visual area of the brain plays a causal role for both perception and imagery

What happened in the case of MGS when the visual cortex was removed?

Size of her visual field was reduced in a mental walk task where she was told to picture herself walking toward an object Shows visual cortex is huge for imagery

Pylyshyn's explanation to imagery as an epiphenomenon (4 parts)

Something that accompanies a real mechanism but is not actually a part of it Like lights flashing as a mainframe computer carries out its calculations Mental images indicate something is happening in the mind but don't tell us how it is happening. Imagery is not spatial, but propositional

How did Farah's 1985 experiment of letter visualization work?

Subject visualizes H or T on screen. Then two squares flash, one after another, on the same screen. Target letter can be in either. Subject determines if letter flashed was same one they imagined. Found subjects were super accurate when they were the same

Kosslyn's 1978 study mental walk task What did this prove about spratial imagery?

Subjects asked to imagine walking toward their mental image of an animal Estimate how long until their object overflows their visual field until the object become hazy and you don't see all of it Had to move closer to smaller animals than larger animals Proved images are spatial like perception

What does Farah's study show about perception and imagery on the neural level?

They share similar neural mechanisms

Bisiach & Luzzatti (1978) asking people with damage to the parietal lobes to imagine things

Unilateral neglect is present when they ask subjects to imagine things they have seen

method of loci

Visualizing items to be remembered in a different locations in a mental image of a spatial layout

IS there evidence for a double dissociation with imagery and perception? Does this mean they have separate or the same mechanisms?

Yes Indicates separate mechanisms

How did Kosslyn's study of mental scanning work? What did he find about imagery?

memorize picture, create an image of it Move from one part of the picture to another Farther something is, it has a higher reaction time Imagery is spatial

fMRI measures what?

brain activity not single neruon firing

Paivio's conceptual peg hypothesis

concrete nouns create imagery that other words can "hang onto" to help remember Ex: land animals easier to remember when you use the word "land" to remember their habitat

mental imagery

experiencing a sensory impression in the absence of sensory input

Is thinking possible without images according to Francis Galton?

people could still think despite trouble forming visual images

Visual imagery

seeing in the absence of a visual stimulus