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