problem 5 - mental images Flashcards
what is imagery?
The mental representation of things that aren’t currently seen or sensed by the sense organs
- Can even represent things that you have never experienced or things that don’t exist outside the mind
- Involves mental representations in any of the sensory modalities
what is the extreme view of imagery?
all images of everything we ever sense is stored as exact copies of physical images → impossible
what is the dual code theory?
We use both pictorial & verbal codes for representing info in our minds
- Codes organize knowledge than can be acted on, stored & later retrieved
analog & symbolic codes
what are analog codes?
Mental images are analog codes (imaginary) = resemble the objects they are representing
- Physical characteristics of an object are registered in your brain in a form that represents the physical relationships
- Mental images we form in our minds are analogous to the physical stimuli we observe
what is symbolic code?
A form of knowledge representation that has been chosen arbitrarily to stand for something that does not perceptually resemble what is being represented
- Language-like description of the physical characteristics of an object
- A symbol can be anything that has been designated to stand for something other than itself - e.g. number 9 is a symbol for concept of ‘nineness’
Brooks (1968): experiment about different systems for verbal/visual recall
- P’s performed either verbal or visual task
- Expressed responses verbally, visually or manually
- Interference measured by slow downs in response times
Results:
- More interference in performing the pictorial tasks when asked to respond using a competing visual display
- More interference in performing the verbal task when asked to respond using a competing verbal form of expression
Suggest the use of 2 distinct codes for mental representation of knowledge
what is the propositional theory?
The propositional form of mental representations is neither in words nor images → it is an abstract form representing the underlying meanings of knowledge
- Both images & verbal statements are encoded & stored mentally represented as propositions
- Our minds re-create the verbal or the imaginal code relatively accurately
- Images are epiphenomena
what are epiphenomena?
secondary derivative phenomena that occur as a result of other more basic cognitive processes
what is image scaling?
Mental zooming in & out
- In general, seeing details of large objects is easier than seeing details of small one → we respond more quickly to questions about large objects we observe
e.g. can see more details on a rabbit when you picture it next to a fly compared to an elephant
what is resolution?
A measure of the ability of the eye to detect two distinct objects when these are close together
- System w high res: can distinguish targets very close to one another as individual entities
- System w low res: can only distinguish targets that are farther apart
Our res is limited - details of large objects is easier than seeing details of small ones
- respond more quickly to questions about large objects
what is the functional-equivalence hypothesis?
Perception & mental imagination are functionally equivalent
- The way perception works with physical objects corresponds to the way mental imagination works with mental representation
image scanning & kosslyn (1978)
Images can be scanned in much the same way as physical percepts can be scanned
+ strategies & responses for imaginal scanning should be the same as for perceptual scanning
Kosslyn: found an almost perfect linear relation between the distances separating pairs of objects in the mental map & the amount of time it took p’s to press a button
- The further away from each other the objects were, the longer it took p’s to scan from 1 object to the other
Handedness & mental rotation
Handedness can influence mental rotation process
- Right-handers recognized a right hand faster than a left hand
- Left-handers recognized right vs left hands equally quickly
- Both groups recognized upright pictures faster & more accurately than upside-down pictures
age and mental rotation
Elderly people perform more slowly on mental rotation tasks
But age is not consistently correlated w other imagery skills (e.g. sense of direction)
deafness & mental rotation
Deaf individuals perform better on mental rotation tasks
Perhaps bcuz they have an advantage from extensive experience in watching a narrator produce a sign → they must mentally rotate this sign
cognitive neuroscience research into mental rotation
- P’s that had originally rotated a geometric figure with their hands = activation in primary motor cortex
- P’s that only watched the rotation of a geometric figure = primary motor cortex not activated
- Change in wording of instructions = different activation in brain
visual imagery & distance
Allan Paivio (1978): creating visual images with 2 hands on a mental analog clock → with real objects, people take long time to make decisions when 2 angles are very similar to each other
- High-imagery p’s made decisions more quickly
- P’s in both groups made decisions slowly when they compared 2 similar angles, and quickly when the angles were different
Supports analog code perspective
visual imagery & interference
Mental images can interfere with an actual physical image
Segal & Fusella (1970): p’s had more problems detecting a physical stimulus when the mental image was in the same sensory mode
what is the bizarreness imagery effect?
Sentences describing unusual or bizarre scenarios are better remembered than sentences describing, every day or common scenarios
- Often attributed to visual imagery bc ppl create a mental image when they read a bizarre sentence
- More effort & elaboration = better remembered
- Distinctiveness
what is the visual-imagery hypothesis?
Non-imagery instructions should reduce the bizarreness effect even if it does not eliminate it, which is a generally found result
BE (recall rate) smaller under visual distractions
Besken et al (bizareness effect) - experiment 1 method
Dynamic visual noise (DVN): rectangular display consisting of small, flickering black & white squares on a screen
- Only disrupts visual imagery & visuospatial info processing
- Shown a mixed list of bizarre & ordinary sentences
- Asked to imagine each sentence being heard through headphones
- Rate on vividness of the image while doing DVN task
Besken et al (bizareness effect) - experiment 1 conditions
Experimental group: DVN + hearing instructions over headphones
Control auditory: heard sentences over headphones (have an exact counterpart to experimental condition)
Visual control: sentences were presented visually
Besken et al (bizareness effect) - experiment 1 results
Vividness:
- Ordinary sentences rated more vividly + more quickly than bizarre ones across all groups
- DVN group got lower vividness scores than the control groups
Recall:
- Visual control condition produced BE: recalled more bizarre sentences than ordinary
- BE significantly greater in the experimental distraction condition than in the control auditory condition
Besken et al (bizareness effect) - experiment 2 method
Spatial tapping task in which participants are asked to repeatedly tap a series of keys in the shape of a figure
- Hinders creation of mental images & mental pathways
- Hinders visual WM more than the DVN test
Same experiment as before but sentences were now presented entirely visually (no headphones) & the distracting task was also entirely visual
