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More Questions How does neural firing affect a frequency of spikes? Why did humans develop both a phonics route and a whole word route? Can words represented by the phonics route have direct access to meaning?
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Questions, Feedback, Issues
Functional websQuestions from studentsOther responses to short papers
Ling 411 – 15
Question about Broca’s aphasia
Broca aphasics have difficulty articulating speech. While their production is good, if they have difficulty comprehending words they omit in speech production, then how can their comprehension possibly be good?
More Questions
How does neural firing affect a frequency of spikes?
Why did humans develop both a phonics route and a whole word route?
Can words represented by the phonics route have direct access to meaning?
Reading – relating writing to speech
Phonologicalword image
Phonemes Letters
The “Phonics” route
Reading – relating writing to speech
Phonological Graphicword image word image
Letters
The “whole word” route
Two pathways for relating writing to speech
Phonological Graphicword image word image
Phonemes Letters
Redundancy?
Two pathways for relating writing to speech
The “whole word” route is necessary for• caught• island• sign
The “phonics” route is needed for long unfamiliar words• commissurectomy• prosopagnosia• magnetoencephalography
Pathway to meaning
Phonological Graphicword image word image
Phonemes Letters
Conceptualinformation
Two pathways to meaning
Phonological Graphicword image word image
Phonemes Letters
Conceptualinformation Another
pathway
Evidence for direct connections between meaning and graphic form
Patient D.R.B. (above)• Judgments of synonymy better for pairs of
written words than pairs of spoken words Patient R.G.B (next slide) Patient H.W. (904)
Yet more questions
How does ERPs work? Is PET the worst imaging type still being used? If so, what
makes it an attractive measurement tool? What would happen if the wires of an MEG machine had
high resistance? Why must so many trials be conducted for each condition
in an MEG test? Is this necessity not a limitation of the MEG?
Two more
15.What functions does ‘monitoring’ from the somatosensory mouth area serve?
16.What types of associations does the angular gyrus make?
From another student: Cardinal nodes
In the class, you mentioned that every functional web has a cardinal node. In the figure you showed in the class, it seems that all the visual nodes are connected to a visual cardinal node. I'm wondering whether there is any evidence to support this assumption about cardinal nodes. If the visual cardinal node is impaired but all the visual nodes are intact, what deficit would a patient show? In the figure, it seems that once the visual cardinal node gets damaged, there is no way to get the visual information to the upper level. Furthermore, if there is a visual cardinal node, where does it localized? in occipital lobe? which part?
Two different patients with anomia
Deficit in retrieval of animal names(Damage from stroke)
Inability to retrieve words for unique entities(Left temporal lobectomy)
Two more patients with anomia
Deficit in retrieval of words for man-made manipulable objects(Damage from stroke)
Severe deficit in retrieval of words for concrete entities(Herpes simplex encephalitis)
Conceptual category dissociation I(from Rapp & Caramazza 1995)
J.B.R. and S.B.Y. (905b-906a) Herpes simplex encephalitis Both temporal lobes affected Could not define animate objects
• ostrich, snail, wasp, duck, holly Much better at defining inanimate objects
• tent, briefcase, compass, wheelbarrow, submarine, umbrella
How to explain?
Conceptual category dissociation II
J.J. and P.S. (Hillis & Caramazza 1991) (906-7)• J.J. – left temporal, basal ganglia (CVA)
Selective preservation of animal concepts• P.S. – mostly left temporal (injury)
Selective impairment of animate category
P.S
J.J.
More on cardinal nodes
I'm also very interested in the concept cardinal node. In the figure you presented in the class, all the cardinal nodes related to a specific concept are connected to this concept cardinal node. I have the same question for this concept cardinal node. If it gets damaged, will the person lost the concept even though all other cardinal nodes related to this concept are intact? I'm very curious about the evidence from neuropsychology.
Functional webs vis-à-vis the linguistic-cognitive network
Linguistic-cognitive network• The whole information system• Occupies all of both hemispheres• Plus subcortical structures• Covers all the information and skills of a person• And all the linguistic knowledge and ability
Functional web• A specific selected portion of the network that is
devoted to a specific function For example, the information and processing
associated with one word
Pulverműller’s functional webs and enhancements
The theory of functional webs presented in class is largely in agreement with that of Pulverműller’s theory
What I presented is certain enhancements:• Clearer definition of node
Pulverműller: a group of neurons Lamb: a cortical column
• Hierarchical structure Goes along with the general hierarchical
structure of the network• Well established
• Cardinal nodes Follows from hierarchy The node at the top of the hierarchy
Relationships among functional webs
How is the functional web related to the general network? What is going on when we ignite two or more functional
webs at the same time?• ‘the dog is chasing that cat’• They are both activated, yet they must remain distinct
The beauty of network structure
Consider the concept BLACK A property of charcoal, some cats, some dresses, etc. Therefore, it is part of the functional web for a lot of
things In a symbolic representation of linguistic-cognitive
structure, it has to get repeated for each of them In a network representation it is there only once
Determinacy and free-will
The issue that is hard to shake when considering these neural networks is the physical determinacy of it all. …
However, by claiming that these nodes deeper within the functional web are activated according to a causal chain of physical events- which is certainly a reasonable enough claim, to be sure- we are actually claiming further and much more profound.
If our minds are patterns of spreading physically determined activation, then only one future course of activation is possible given any particular combination of stimulations … at a particular moment.
If an alternate pattern of activations is not possible, then in at least one philosophically important sense, no such being is capable of exercising free will.
end
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