Week 11 Flashcards
What is the mind?
“The element of a person that enables them to be aware of the world and their experiences, to think, and to feel” (Oxford Dictionary) Phantom limbs… – The brain represents the limb, even if it is not there anymore
The representational mind
What are representations? – Representations are ABOUT something Representations have a REFERENT and a SENSE Two types of representation: – Analogue representations • E.g., analogue clock, photograph, map – Propositional representations • E.g., digital clock, language
Imagery
What is imagery? Why is it important? – Frees us from the present – Frees us from reality – Allows us to practice without moving – Mental maps
Paivio’s dual coding hypothesis
Information is represented in a verbal and an
imaginal (visual) code
It might be coded or stored in either or both systems
– Concrete words are remembered better than abstract words
• concrete words can be stored in both verbal and imaginal
codes while abstract words may only be stored in verbal code
Conceptual-Propositional
Hypothesis
Anderson & Bower
Predicate (or propositional) calculus
– {relationship (subject, object)}
• E.g. {kissed (boy, girl)}
Analogue storage is beyond our capacity
Storage likely to be in a propositional formatEvidence for propositional effects
in mental imagery
“Which one did you see?” barbells or spectacles Transformations Size effect Image scanning
Functional Equivalence
Hypothesis (Shepard & Kosslyn)
Mental imagery is not abstract propositional, but it
is also not a simple analogue representation of the
external world
Relationships between objects in imagery are
functionally equivalent to the relationships these
objects have in the real world
E.g., if A is taller/heavier/smellier/wetter/hotter than B in
reality, then same relationships are preserved in imagery
Perception and imagery use same cognitive
mechanisms
– Perception is instigated bottom-up, imagery top-down
Mental rotation
Mental rotation
Imagining objects from different angles
Continuing controversy
Propositional accounts (e.g., Pylyshyn) continue to
question the evidence for functional equivalence
– E.g., effects may be explained by demand characteristics
– But baboons show same rotation effect…
Note that one does not need to assume that we form
a representation of an object and then rotate it
– we may form a representation of a rotating object
Mental images behave similarly to physical objects,
because their evolutionary function is to represent
the physical world
Does imagery use the same cognitive
resources as visual perception?
Interference effects Rotation aftereffects (e.g., Corballis & McClaren) Imagery interferes with perception (e.g., Segal & Fuscella) – task 1- auditory detection task (did a tone occur?) & task 2- visual detection task (was a line presented on the screen or not?) – Do these tasks whilst imagining 1- a telephone ringing (auditory) or 2- a visual scene – Auditory/auditory or visual/visual = many errors – Auditory/visual or visual/auditory = few errors
Does dream imagery also
interfere with perception?
Dreams reported as visual and
kinesthetic experiences rather than as
auditory, tactile or olfactory
Symons’ interference hypothesis:
• we could afford visual and kinaesthetic hallucinations
because our eyes are closed and we’re not moving anyway
• but alarm cries, smell of predators, panicky grasp of an infant
remain important cues that require unimpaired vigilance of
the senses of hearing, smell and touch during sleep
Multiple Choice example
In their mental rotation study, Shepard and Metzler found a linear
relationship between degree of rotation and reaction time. If you
look at a clockwise spinning disc for 30 seconds before a trial,
and you are asked “is the one on the right the same as the left?”
a. the linear relationship should disappear over trials
b. you are more likely to get it right
c. your reaction time is likely to be slower than normal
d. your reaction time is likely to be faster than normal
Lesions and impairments in
perception and imagery
Bisiach & Luzzatti – Damage to right parietal lobe -> visual neglect syndrome – Neglect also in imaginary space Farah – Reduced image size after occipital lobectomy in vision (tunnel vision) and in imagery (tunnel imagery)
Neurocognitive imaging studies
and mental imagery
PET scans
– imagery results in occipital & temporal parietal activation
• primary visual and higher memory areas
– greater activation in visual cortex when imagining than
when perceiving
• i.e., top-down more demanding than bottom-up
image creation
ERP
– participants who claim to have vivid imagery show
stronger occipital ERP effects
‘Mentalese’:
the language of the mind
Thinking can be in verbal and imaginal form
(i.e., Paivio’s dual-coding hypothesis), but
also in propositional form
– some insist that it all boils down to propositions
Imagery engages some of the same
cognitive resources as perception and
shows some functional equivalence
– neurocognitive studies lend further support to this
notion
