7 The Literate Brain Flashcards
lexico-semantic route
Convert visual information and read it out loud in speech production
Two possible routes
Lexical semantic route. Word from understand meaning access pronounciation and then read it out loud
phonological route
Correspondence between letter features and how they should be pronounced and can convert that through graphemes to phoneme conversion through this route then read it out loud
reading
communicating some sort of meaning
how meaning is represented in the brain
chinese room problem
Sitting in a room with dictionary
Input - look in dictionary and see it means that
Looks as if understood Chinese language but not really
Can convert one character to other but its just random
If swap character makes no difference bc no rules or constraints to say this character has to be explained by this character
Arbitrary
No meaning to any of the symbols
the third dictionary
Third dictionary
Meaning provided - images
Perceptual experience meaning
More meaningful than random characters
One is experience based and one is symbol based
Two kinds of meaning form basis of two theories about how meaning is represented in the brain
what are the two ways language meaning is mentally represented
amodal experience
embodied cognition theory
amodal experience
Amodal symbol
All mental representation abstract codes or symbols
Amodal symbol system
Representational system
problems with amodal symbols
no rules telling you which symbols to use
computer like
letters digits binary codes
No intrinsic physical differences between the symbols
Same thing different values
Expected to be processed and represented in one place inside the brain
Transistors - neurons
Firing or not firing use to represent a 1 or 0
Code - symbolic language
embodied cogntition theory
Cannot be symbols bc just random
Different parts of chair transduced through selective attention
Focus on different parts of the experience
E.g. shape colour tactile experience of sitting on chair remember sensations
Representations are experience based
what is embodied cognition theory
Experienced based
Different kind of experiences processed and represented in different sensory systems
Motor systems - motor experiences
Auditory - sounds
Multi-sensory representation of that concept
Some physical resemblance to the actual meaning the language is trying to refer to
mental representations as abstract symbols
Abstract symbols Access its actual meanings Number of things in world to refer to The symbols themselves aren’t different Binary code not instrinsically different just have different values Can’t distinguish
Symbols randomly arbitrarily generated
Not grounded in anything
Symbols random and abstract- no meaning itself
No constraints to force them to refer to a particular thing or meaning
what is the symbol grounding problem
E.g. stuff or thingy
Can refer to anything
Then itself has no meaning
Only meaning when has certain constraints and can only refer to one thing and not the other
mental representations as seonsory experiences
Activate sensory experience
Mental simulation
A form of imagery
Reactivates certain elements of chair - shape texture
Depends on what meaning you need to access for your current purpose
Chair among objects - shape
Perceptual Visio spatial representation about the chair
Can make physical contraints
Certain physical constraints
Refer to actual meaning
what is activation in embodied cognition
mental simulation
behavioral observations in amodal
language has nothing to do with perception and action
Language processed in central processing unit Dealing with symbols Nothing to do with perception and action Totally different Two things are independent
behavioural observations in embodied cognition
Language processing itself will interact with ongoing perception and action
Language meaning
Perceptual and motor experiences interacting with chair
Mental representation for meaning - sensory experiences
Make very different predictions if you were to do experiments looking at language processing in perception and action
stanfield and zwan - pencil
Read sentences
Pictures
Ask people is this object mentioned in sentence
How fast say yes
Amodal system - pencil - symbols - binary code
Pencils represented the same - no difference in how pencil is represented
Doesn’t matter if pencil is represented vertically or horizontally
How fast say yes wont matter?
Not the case - orientation of pencil does make a difference
findings from pencil study
Match and mismatch difference in response time
Visual representation is being represented in the brain
Faster when orientation matches - priming - preactivation of a particular orientation
Warmed up those neurons that represent that orientation
Makes picture processing faster
Ready for vertical orientation - easier to process- quicker response
Different orientation - reconcile the difference - response slower
picture verification task
reading vs sensory perception
visual shape
egg in box egg in pan
react different speed depending on match or mismatch in sentence
reading vs sensory perception
visual colour
steak in window
steak on plate
spatial location
hat
cowboy
boots
Associated with that concept is being activated
Interacts with how see and process words on screen
Makes sense
How spatially arranged in real life
If spatial location is incongruent with how should be
Or how understand conceptually - takes longer to process
reading vs body movements - glenberg
faster when actions match
amodal symbolic theory predictions - neural observations
Represented and processed in a single symbolic system
Deals with whichever symbol you have in mind
a central language processing unit
embodied cognition theeory
perception symbol theory
Logographic e.g. Chinese some resemblance
Normally language form doesn’t have meaning at all
Actual experience or meaning it refers to thats meaningful
That meaning is not abstract its sensory enhanced
Core language system to serve as indexing system to relate symbols to meaning
Language system isn’t exclusively for language - network - text to meaning
embodied cognition predictions - neural observation
No single language area Language processing - peripheral systems Semantic system Language symbol reference system Activate what it refers to Text itself has no meaning
distributed - engage different brain symbols
the homunculus
Which part of brain is activated by reading action words
Brain is organised - homunculus
Represents how much neural resources dedicated to control hand and faces
Speech - neurons - complex articulatory gestures
topographically organised motor cortex
Different parts of body are typographically mapped to different parts of your motor and somatosensory cortex
Mapped in a spatially inverse relationship
TMS machine - change magnetic field around coil - magnetic fields penetrate skiull and generate electric current to certain parts of the brain
Disrupt the functions of that or activate that area - cause body movement
Left brain - right half of body
different parts of motor cortex active in fMRI when read different kind of action words
Motor cortex - somatosensory sensory cotrtex
FMRI - mapping increases of oxygen level in different parts of the brain
Asked people to make actual body movements in the scanner
Different parts of motor cortex being activated by different action
When read different action words
If all words represented in binary code - should be represented in single symbolic system - not the case
Understanding these actions involves th activations of the motor system
Kicking - activates superior part of the motor or cortex
Activation pattern slightly different from what happens in real action
Understanding of different actions in language is also typographically organised
Discredited the amodal symbol system which predicts that theres a central language processing are - not the case
Distributed semantic system for action words
single pulse TMS
Single pulse TMS
Only make a single pulse each stimulation which will generate some kind of potential responses in different parts of the body - the nerve will transmit the signal to your hand or loge depending on which part of the motor cortex has been stimulated
Stimulate either the right hand area or right foot area
Record muscle responses from opponent sympolicis
hand and leg
There’s a reverse pattern
Depending on which motor area stimulating
Stimulating hand - MEPS after reading hand action is smaller than foot
Foot muscle activity is reduced after reading foot actions to hand actions
It does make a difference depending on which motor system activating or stimulating and which type of actions your reading
Match mismatch difference
Why see reduction?
If read kicking - engage foot muscle system - interferes with Mep - a response to single pulse TMS but not response to foot action
Interference - reduction in activation
Stimulation to different parts of motor cortex is differentially modulated by which kind of action words your listening to
hand verbs -
motor evoked potentails smaller than leg
foot verbs
hand muscle MEPs higher than foot
reading vs multimodal experiences
No single language area for all these changes
Character - temporal parietal temporal junction
Goal - parietal frontal
Object- dorsolateral prefrontal , motor area somatosensory parietal junction occipital temporal
Time - mid prefrontal area
do parkinsons patients have difficulties understanding actions in speech
Parkinson’s patients do have specific impairments in understanding actions - not just for literal actions but for metaphorical and idiomatic actions as well
Suggests that although in the dictionary idiomatic action doesn’t mean pinching pennies but the way brain understands this Acton phrase is perhaps through simulations of the actual actions
parkinsons vs control
abstract vs literal
Non distinguishable for control
Patients overall slower - difficulty understanding
Literal - longer than control
parkinsons vs control
abstract vs metaphoric
Significant - metaphoric
Understood in terms of physical action - much slower
parkinsons vs control
abstract vs idiomatic
Idiomatic - high frequency phrases
Understood together rather than individual words
Familiarity advantage
Patients dont have the difference
Delayed in Parkinson’s
idiomatic action
description isnt fixed
mean something else
abstract verb
doesnt involve motor body movement
amodal represetnations
language doesnt use perception and action
a central language processing unit
embodied representations
language and perception and action work togehter
a distributed semantic system
inference
real world representation
future research directions
Outstanding issues
• Is all meaning represented in embodied experience?
• Abstract concepts?
• How flexible is mental simulation? What are the mechanisms?
Reactivate reconstruct sensory information from memories
Don’t know mechanisms
Sensory systems
Humans can create an internal world
Reconstruct experience
What could or might happen in future
