Wk 6 - Imagery/Foresight Flashcards
Three theories of imagery are…
Which differ largely on
Paivio’s dual-coding hypothesis
Conceptual-Propositional Hypothesis (Anderson and Bower)
Functional equivalence hypothesis
Whether we encode in analogue or propositionally
Four pieces of empirical evidence for the claim that imagery involves similar processes as perception includes…
NEUROSCIENCE: Damage to visual areas = corresponding damage to imagery; activation in visual cortex when imagining.
SIZE EFFECT: Takes longer to answer a question about a small object in imagery than a large object
IMAGE SCANNING EFFECT: More time required to mentally scan further distances across visual imagery, just as it would perceptually
INTERFERENCE EFFECTS: Visual imagery interferes with visual perceptual processing, auditory imagery interferes with auditory perceptual processing, not vice versa
Representations… (x1)
Consist of two components
Exist in themselves, and also stand in for something else
Referent: what is being represented
Sense: how it is being represented
Two types of representations
Debate continues as to whether… (x1)
Analogue: a 1:1 relationship, e.g. photo of a room
Propositional/allegorical: arbitrary, use of symbols combined under rules - can be true/false, allows separation of elements e.g. brown and dog
The mind is analogue or propositional
Imagery is…
Allowing us to… (x2)
And is useful in… (x3)
Ability to imagine scenes, music, sensations etc, in absence of physical presence
Perform operations and gain knowledge from them – eg how many doors in your house? (mental ‘walk’)
Mental time travel – eg my house at age 10;
Creation of non-real worlds and mental maps (found in other animals - rats can get through maze first time);
Imagined practice – helps real world performance
Paivio’s dual coding hypothesis of imagery argues that… (x1)
Eg… (x1)
Evidence for… (x2)
Info is represented in verbal and imaginal code
London cabbie using imagery and propositions
Info coded or stored in either/both:
Concrete words remembered easier than abstract – are in both codes, eg a t.a.b.l.e and a picture of, while abstract only in verbal
And concrete words can be put together in scenario for easier remembering
The conceptual-propositional hypothesis of imagery argues that…
And is evidenced by two studies (x3 + 1)
We store meaning/interpretation, not analogue components
Tested subjects with {relationship (subject, object)}, so {kissed (boy, girl)}
Remembered hearing related words not in original list just as well as those that were
Conclusion – too much info to store analogue, so must be propositional storage (even images)
Same image with barbell or spectacle written next to it
Barbell condition stated having seen longer line between 2 circles than had in fact, spectacle claimed to have seen shorter (top-down processing)
The functional equivalence hypothesis of imagery argues that… (x1)
Based on evidence showing… (x2)
Which strongly suggests…
It’s not direct 1:1, but not purely abstract either
Map/image relationships are functionally equivalent
Mental rotation - takes longer to rotate 180 than 20 degrees (linear effect with reality)
Common neural mechanisms for imagery/perception
Mental rotation experiments find that... Results are challenged by... (x1) But supported by... (x1) Doesn't require assumptions of... (x1) And strongly suggests... (x1) Analogue imagery... (x1)
In RL, takes longer to rotate 180 than 20 degrees – same in imagery (same linear effect)
Those claiming demand effects – participants working out what’s expected of them
Same analogue relationship effect found in baboons
A 2-step process, a representation that we then rotate – maybe rep of rotating object (as yet unresolved)
Common neural mechanisms imagery/perception
Makes evolutionary sense
Evidence for analogue effects in mental imagery… (x3)
Transformations: eg D, rotated 90o, put 4 on top – looks like a sailboat
Visual size effects (Kosslyn): object that’s bigger in your mind is easier to answer question about; eg tail on a frog? Next to fly/elephant
Image scanning: linear relationship between distances on map, and time taken to travel mentally; propositionally, you’d be there instantly
Symons’ interference hypothesis of dreams argues that we… (x1)
Resulting in… (x1)
Because we need to… (x1)
Can afford visual/motor hallucinations while sleeping - not using those systems anyway
Visual/kinaesthetic dreams, ot auditory/tactile/olfactory
Need to be vigilant to danger while asleep
Bisiach and Luzzatti studied Ps with lesions to right parietal lobe
Condition’s name and effect
Procedure (x2) and findings (x1)
Visual neglect syndrome - ignoring left side of visual field
Had Ps name the buildings in piazza (in imagery)
Then ‘turn’ and come back through
Found that neglect transferred to imaginary space
Three pieces of evidence for common perceptual/imagery processes from metabolic imaging studies
PET scans found increased activity in occipital/temporal parietal areas: visual and memory – need to retrieve it in order to imagine it, and greater activation for image than perception – top-down is more demanding
ERP shows more occipital ERP effects among those who claim strong imager abilities
Single-cell recordings: train a monkey to point at the light to get a banana – different cells light up for each direction pointed; if trained to point at 90o to light, cells light up as if the monkey were moving it’s arm in an arc from light to required point in space
Summary of findings on mentalese - the language of the mind… (x4)
Storage of likely to be propositional, so don’t run out of space
Thinking is analogue and prop
Some debate for purely propositional, but contradicting evidence exists
Image/perception use same resources and are functionally equivalent (supported by neuro studies)
Our own private time machine uses… (x2)
And allows… (x1)
Episodic memory: imagining/reliving the past
Episodic foresight: pre-living the future
Reflection/evaluation, and preparing/shaping
