Chapter 10 - Imagery Flashcards
1- What is imagery?
Imagery:
Broadly defined as the ability to recreate* a
perceptual experience in the absence of an
external sensory stimulus
*However, you don’t need to have
experienced something to imagine it
Qualities of imagery: Vividness
Vividness typically refers to how clearly we can create an image in our mind’s eye
How vivid are mental images?
◦ Varies across individuals and contexts
◦ Familiarity may enhance vividness of mental images (Baddeley & Andrade, 2000)
◦ Musicians seem to hear musical imagery more often than non-musicians (Beaty et
al., 2013)
Individual differences in imagery
In class, we have discussed vision as
being one of our dominant senses…
does this also hold for imagery?
◦ When recalling past personal events,
some people tend to do this primarily
with visual images and others with
words
◦ We can compare use of different types
of imagery across these “visualizers”
and “verbalizers”
Visual Imagery: Visualizers = Verbalizers
Auditory Imagery: Visualizers < Verbalizers
***rewatch part lecture to understand what this means
2- How do we create mental images?
Dual-Coding Theory (Paivio, 1971)
◦ Breaks down the mental representation of events into two categories
the word: cat + the mental image of a cat
◦ There are some exceptions, like onomatopoeias where the word resembles
the sound; however, these also vary across languages
ex: english=hahaha, spanish=jajaja, portuguese=kkk
◦ While this theory was useful for thinking about imagery, it was proposed as
a theory for how we represent thoughts more generally…
How do we represent mental images?
The imagery debate
There are two opposing viewpoints for
how we form representations of mental
images:
1. Stephen Kosslyn: Imagery is an
analogue form of representation
2. Zenon Pylyshyn: Imagery is a byproduct of a symbolic code. Ex: Right (toaster, stove)
Kosslyn’s Depictive Representation Theory
Knowledge… divided into an image of a toaster to the right of a stove + “The toaster is right of the stove”
Pylyshyn’s Propositional Theory
Knowledge…Right (Toaster, Stove)…divided into an image of a toaster to the right of a stove + “The toaster is right of the stove”
3- What brain mechanisms support imagery?
The imagery debate: Evidence from
mental scanning
Reaction time is related to time required to scan a mental image (Kosslyn, 1973)
◦ Kosslyn, Ball, and Reiser (1978) had
participants scan a memorized map
where the number of landmarks
was the same but the distance
varied
◦ Again, the further the scanning
distance the longer the reaction
time
The imagery debate: Evidence from
mental rotation
The time to respond is positively related to the amount the image must be
rotated
The imagery debate: Evidence from
mental scaling
◦ Kosslyn (1975) asked participants to imagine certain features of the animal
◦ Scale of the animal was small or large in comparison with a second animal
Is Cog Cat’s mouth open?
**See what this means
Imagery versus perception
We’ve seen extensive evidence suggesting that imagery is an analogue form of representation, preserving features of percepts
1. Is behavioural performance on tasks with mental images and percepts similar?
2. Do similar brain mechanisms support imagery and perception?
Imagery versus perception
Crowder (1989) conducted a series of experiments examining participants judgements of musical tones
Participants were faster at responding when the tone was played by the same instrument
What if people are asked instead to imagine the timbre?
Auditory imagery versus perception
1) People are presented with a pure tone (single frequency, no harmonic spectrum), and are asked to imagine this tone played by
a specific instrument (guitar, flute, or trumpet)
2) People are presented with a second tone played by one of three instruments (guitar, flute, or trumpet)
3) People judge whether the second tone is the same as or different from the first tone
If auditory imagery is similar to perception, what results should we expect?
People were faster at saying that two notes were the same when the perceived timbre was consistent with the heard timbre
Are similar brain areas active during auditory imagery as during auditory perception?
Participants either listened to or imagined sounds inside an fMRI scanner
1) Perception: Sound of the instrument with its corresponding name on the screen
presented to participants
2) Auditory Imagery: Participants imagine sounds corresponding to the instrument
name presented on the screen
***Results???
Visual imagery versus perception
Kosslyn et al. (1999) showed that
visual imagery and perception tasks evoked activity in primary visual cortex
Is there evidence against depictive
representation?
-If imagery is a depictive representation, participants should easily be able to identify components of memorized images
This is not actually the case…
-There is also evidence from patients with brain damage that imagery may not
entirely rely on the same neural mechanisms
4- How does imagery affect cognition and behaviour?
Imagery and memory (with piano)
1) Normal performance feedback:
Play normally through the piece of music
2) Motor only performance feedback:
Play through the piece of music without hearing the performance, imagine what it sounds like
3) Auditory only performance feedback:
Hear the piece of music, imagine what the movements feel like
4) No performance feedback:
Imagine what the piece of music sounds like, and what the movements feel like
Results:
Memory performance decreases as feedback
available at practice decreases
Best to worst: normal, auditory, motor, covert
BUT
Low on Auditory Imagery (white bars):
Memory performance decreases as
feedback available at practice
decreases
High on Auditory Imagery (black bars):
Auditory imagery compensates for lack
of feedback, not as much of a
decrease in performance
AND HUGE DIFFERENCE IN MOTOR CONDITION
Imagery and memory
Items represented as images are better remembered than those represented as words (Paivio & Csapo, 1973)
Ex: word cat vs. image of cat
This effect is disrupted after a period of watching dynamic visual noise (like tv with no signal thing) (Parker & Dagnall, 2009)
5- What happens when things go wrong?
Imagery and mental health:
Negative imagery seems to be linked
to severity of several psychological
disorders, including depression, anxiety,
and post-traumatic stress disorder
Interesting cases of imagery: Synesthesia
A Reminder…
◦ Synesthesia is a sensory experience in which a stimulus in one sensory modality also invokes a response in one or more other sensory modalities
◦ Chromesthesia is the most common experience among synesthetes (sound=colour)
How does synesthesia influence memory?
◦ Synesthesia may aid memory in specific cases
◦ Participants with chromesthesia and absolute pitch have reported that their
chromesthesia aids their memory for specific pitches and music (Rogers, 1987)
Interesting cases of imagery: Amusia
Amusia: deficits in musical abilities; also called tone-deafness
◦ People with amusia have been shown to have deficits in visual/spatial imagery
◦ Imagery in different sensory domains may interact with one another
