Interpreting Neurolinguistic Evidence Careless thinking and critical thinking

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Interpreting Neurolinguistic Evidence
Careless thinking and critical thinking
Ling 411 21
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Schedule of Presentations
Tu Apr 13 Th Apr 15 Tu Apr 20
Th Apr 22
Delclos Planum Temp Banneyer Categories Ruby Tso Writing Bosley Synesthesia
McClure Gram.-Broca Ezzell Lg Dev. (Kuhl) Rasmussen 2nd language Brown LgThought
Gilcrease-Garcia AG Koby Music Tsai Tones
Roberts MTG Mauvais LH-RH anat. Shelton Thalamus
Delgado Amusia Joyce Liu RH functions
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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Retrieval of words, meanings
• Communication between subsystems

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Wernickes area and speech production
Examples of careless thinking Steven Pinker
Wernickes area was once thought to underlie
language comprehension. But that would not
explain why the speech of these patients sounds
so psychotic. The Language
Instinct (1994) Friedemann Pulvermüller patien
ts with Wernickes aphasia have difficulty
speaking. These deficits are typicaland cannot
be easily explained by assuming a selective
lesion to a center devoted to language
comprehension. The Neuroscience of
Language (2002)
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Perceptual structures in motor production

• Perceptual structure is used in two ways
• Planning (e.g. visualizing while painting)
• Monitoring
• Examples
• Phonological recognition in speech production
• Cf. Wernickes aphasia
• Painting
• Musical production
• Baseball, soccer, tennis, etc.

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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Retrieval of words, meanings
• Communication between subsystems

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Brocas area and speech production - I
Careless thinking previously considered John
Pinel (Biopsychology textbook) Surgical
excision of Brocas area failed to result in loss
of speech production (after recovery from
surgery)
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Brocas Area Not for Speech Production?
Surgical excision was done in two stages.
Following completion of the second stage, no
speech-related problems were reported.
Patient D.H.
John Pinel, Biopsychology (1990560), Adapted
from Penfield Roberts, 1959
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Brocas Area Not for Speech Production?
What Pinel neglects to mention, but it is in
Penfield Roberts Patient D.H. was a young boy
who had been having seizures, originating in this
part of his brain.
Patient D.H.
John Pinel, Biopsychology (1990560), Adapted
from Penfield Roberts, 1959
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More on patient D.H.

• Eighteen years old at time of surgery
• Had suffered from seizures causing an inability
  to speak from the age of 3 1/2
• Apparently, the congenital abnormality had
  caused displacement of function

Penfield Roberts Speech and Brain
Mechanisms (1959 163)
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Brocas area and speech production - II

• Influential paper by Alexander et al. (1990)
• Motivation for the study
• Maybe its not just Brocas area damage that is
  responsible for some of the symptoms of Brocas
  aphasia
• Maybe some of them result instead from damage to
  neighboring areas
• They studied a group of patients
• Distinguished 3 subtypes of Brocas aphasia

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Three subtypes in Alexander study

• Impaired speech initiation
• Symptom traditionally attributed to transcortical
  motor aphasia
• Area of damage frontal operculum
• Disturbed articulatory function
• Area of damage lower primary motor cortex
• The classical Brocas aphasia syndrome
• More extensive damage

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Type I

• One patient
• Area of damage
• Frontal operculum
• Adjacent middle frontal gyrus
• Subjacent subcortical white matter
• Speech quality normal
• Normal repetition
• Speech terse and delayed in initiation
• Speech grammatically correct!
• Anomia and semantic paraphasias

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Insula and operculaView with opercula pulled
back to expose insula

Short gyri of insula Long gyrus of insula Superior temporal gyrus Circular sulcus of insula Frontal operculum Frontoparietal operculum Temporal operculum
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Original Brodmann Map - Colorized Outlines -
with Functional Attribution
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Type I critical appraisal

• Area of damage
• Frontal operculum
• Adjacent middle frontal gyrus
• Subjacent subcortical white matter
• Symptoms
• Speech quality normal
• Normal repetition
• Speech terse and delayed in initiation
• Speech grammatically correct!
• Anomia and semantic paraphasias
• The symptoms are those of transcortical motor
  aphasia

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Type I (contd)(from Alexander study)

• Other relevant studies
• Patients with frontal operculum lesion but with
  primary motor cortex spared
• Symptoms like those usually called TCMA
• Speech output
• Terse, laconic
• Grammatical, sentence-length
• Semantic paraphasias
• Normal articulation
• Evidently, damage to subjacent white matter is
  essential for lasting aphasia after lesions in
  the frontal operculum (Alexander et al. 1990
  357)

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Type I (contd)(from Alexander study)

• Other relevant studies
• Patients with frontal operculum lesion but with
  primary motor cortex spared
• Symptoms like those usually called TCMA
• Speech output
• Terse, laconic
• Grammatical, sentence-length
• Semantic paraphasias
• Normal articulation
• Evidently, damage to subjacent white matter is
  essential for lasting aphasia after lesions in
  the frontal operculum (Alexander et al. 1990
  357)

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Type I (contd)(from Alexander study)

• Other relevant studies
• Patients with frontal operculum lesion but with
  primary motor cortex spared
• Symptoms like those usually called TCMA
• Speech output
• Terse, laconic
• Grammatical, sentence-length
• Semantic paraphasias
• Normal articulation
• Evidently, damage to subjacent white matter is
  essential for lasting aphasia after lesions in
  the frontal operculum (Alexander et al. 1990
  357)

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Type II

• Patients 2-6 in Alexander et al. (1990) study
• Areas of damage
• Frontal operculum
• Lower primary motor cortex
• Anterior insula
• White matter deep to these regions
• Right facial paresis and mild right hand weakness
• Defective articulation
• Sentence-length grammatically normal utterances!
• Except for initiation struggle
• Except for patient 6 single word utterances

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Type II (contd)

• Other studies support the attribution of
  dysarthria to primary motor cortex
• Patients with
• Small shallow lesions in lower motor cortex
• Frontal operculum not involved
• Labels that have been used
• Aphemia
• Cortical dysarthria
• Apraxia

(Alexander et al. 1990 357)
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Type III

• Patients 7-9 in Alexander et al. (1990) study
• Areas of damage
• Lower motor cortex and/or subjacent white matter
• Anterior superior insula
• Lateral putamen (a nearby subcortical structure)
• Frontal operculum spared
• Right central facial paresis
• Aphasia symptoms similar to Type II
• Including absence of agrammatism
• Phonemic paraphasias in repetition
• One patient (9) had virtually no speech output

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Receptive agrammatism

• All cases had some impairments in auditory
  comprehension at the level of complex sentences
  or multistep commands. (Alexander et al.
  1990 360)
• Indicates short-term memory deficit

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Confounding factors

• We did not evaluate any of the patients in the
  acute phase of their illnesses all were referred
  to the Boston VAMC for speech and language
  therapy. (Alexander et al. 1990 353)
• Localization of lesions was done by CT scan not
  sensitive enough to detect small areas of damage
  (360)

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The importance of plasticity

• In the acute phase, these patients may have
  traditional, nonfluent aphasia articulation
  impairment, prosodic impairment, and
  agrammatical, shortened utterances. The evolved
  disorder is, however, much less severe than that
  grammatical, sentence-length utterances return,
  albeit still labored and paraphasic and with
  speech impairment.
  (Alexander et al. 1990361)
• Recovery is not so good if extensive white matter
  involvement

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Another study

• Taubner, Raymer, and Hellman 1999,
  Frontal-opercular Aphasia 5 types
• Verbal akinesis like Trans-cortical motor
  aphasia supplementary motor area and cingulate
  gyrus
• Disorders of grammar pars opercularis
• Phonemic disintegration primary motor cortex
• Defects of lexical access pars triangularis and
  adjacent frontal cortex
• Mixed defects

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Proceed with Caution!

• How should we interpret the results of the
  Alexander study?
• Some researchers have concluded that damage to
  Brocas area is not responsible for Brocas
  aphasia after all
• Reason No lasting impairment of speech
  production if only Brocas area is damaged,
  without white matter involvement
• Alternative explanation?

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Alternative explanation

• Plasticity
• N.B. Patients were examined only after they had
  had time to recover, not in the acute phase
• The evidence indicates that
• Functions of Brocas area can be partly regained
  by recruitment of neighboring area(s)
• But such recovery is impaired if there is also
  damage to subjacent white matter

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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Retrieval of words, meanings
• Communication between subsystems

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Friederici Fig. 1
Syntactic networks in the human brain. (a)
Depicts the two neural networks for syntactic
processing and their fronto-temporal involvement
(function) schematically.
(b) Shows fiber tracting as revealed by DTI
(structure) in an individual subject top right,
with the starting point (green dot) being BA 44
and bottom right, with the starting point (blue
dot) being the frontal operculum.
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Friederici Figure 2
Fiber tracts between Broca's and Wernicke's area.
Tractography reconstruction of the arcuate
fasciculus using the two-region of interest
approach. Broca's and Wernicke's territories are
connected through direct and indirect pathways.
The direct pathway (long segment shown in red)
runs medially and corresponds to classical
descriptions of the arcuate fasciculus. The
indirect pathway runs laterally and is composed
of an anterior segment (green), connecting
Broca's territory and the inferior parietal
cortex (Geschwind's territory), and a posterior
segment (yellow), connecting Geschwind's and
Wernicke's territories.
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Wernickes Brocas areas for syntax?
Combining functional MRI and DTI, two of these
pathways were defined as being relevant for
syntactic processes 44. Functionally, two
levels of syntactic processing were
distinguished, one dealing with building a local
phrase (i.e. a noun phrase consisting of a
determiner and a noun the boy) and one dealing
with building complex, hierarchically structured
sequences (like embedded sentences This is the
girl who kissed the president). DTI data 44
revealed that the frontal operculum supporting
local phrase structure building 14 and 44 was
connected via the UF to the anterior STG which
has been shown to be involved in phrase structure
building as well 14. The dorsal pathway
connects BA 44 which supports hierarchical
structure processing 42 and 45, via the SLF
to the posterior portion of the STG/STS, which is
known to subserve the processing of syntactically
complex sentences 51 I. Bornkessel et al., Who
did what to whom? The neural basis of argument
hierarchies during language comprehension,
Neuroimage 26 (2005), pp. 221233. Article PDF
(300 K) View Record in Scopus Cited By in
Scopus (53)51. This latter network was,
therefore, taken to have a crucial role in the
processing of syntactically complex,
hierarchically structured sentences.
(Friederici 2009, p. 179)
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Critique of Friederici paper by Weiller et al.
(August 2009)
Friederici claims the dorsal pathway to be
crucial for the evolution of human language,
which is characterized by the ability to process
syntactically complex sentences. As suggested
in our paper, the involvement of the dorsal
stream for processing of complex syntactic
operations might be partially explained as a
result of an increase in syntactic working memory
load 2. Syntax and memory are hard to keep
apart. Trends in Cognitive Sciences vol. 13,
Issue 8, September 2009. pp. 369-370.
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Hickok on phonological working memory
Brocas area and the SMG are involved in
speech perception only indirectly through their
role in phono- logical working memory which may
be recruited during the performance of certain
speech perception tasks. Hickok 2000
97 The sound-based system interfaces not only
with the conceptual knowledge system, but also
with frontal motor systems via an auditory-motor
interface system in the inferior parietal lobe.
This circuit is the primary substrate for
phonological working memory, but also probably
plays a role in volitional speech
production. Hickok 2000 99
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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Retrieval of words, meanings
• Communication between subsystems

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Impairment of nominal concepts

• Access to nominal concepts is impaired in
  extra-sylvian sensory aphasia
• Type I Damage to temporal-parietal-occipital
  junction area
• I.e., lower angular gyrus and upper area 37
• Poor comprehension
• Naming strongly impaired
• Semantic paraphasia
• Type II Damage to upper angular gyrus
• Variable ability to comprehend speech
• Naming strongly impaired
• Few semantic paraphasias
• Many circumlocutions

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2 Cases of Rapp Caramazza (1995)

• E.S.T. (901b) Left temporal damage
• Meaning spared, couldnt say the word RC
• J.G. (902a) Left posterior temporal-parietal
• Meaning spared, couldnt spell the word
  correctly, but phonological recognition okay

Cf. Rapp Caramazza, Disorders of lexical
processing and the lexicon (1995)
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Patient E.S.T. (RappCaramazza 1995901b)

• Left temporal damage
• Shown picture of a snowman
• Unable to name it
• Its cold, its a ma cold frozen.
• Shown picture of a stool
• stop, step seat, small seat, round seat, sit
  on the
• Shown written form steak
• Im going to eat something its beef you can
  have a së different costs more
• What can we conclude?

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Assessment of E.S.T. by Rapp Caramazza

• Responses of E.S.T. indicate awareness of the
  meanings (SNOWMAN, STOOL, STEAK)
• Therefore, meaning is spared (according to Rapp
  Caramazza)

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Warning Proceed with caution

• The assumption of RappCaramazza is easy to make
• I.e., that meaning (conceptual information) is
  spared
• But theres more to this than meets the eye!
• As we have seen, conceptual information is widely
  distributed
• We only have evidence that some of the conceptual
  information is spared

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Patient E.S.T. a closer look

• Left temporal damage
• Picture of a snowman
• Its cold, its a ma cold frozen.
• Picture of a stool
• stop, step seat, small seat, round seat, sit
  on the
• Written form steak
• Im going to eat something its beef you can
  have a së different costs more
• These are not definitions
• This is connotative information
• Vague semantic notions about the meanings

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Compare patient J.G. (902a)

• Damage Left posterior temporal-parietal
• Meaning spared, couldnt spell the word
  correctly, but phonological recognition okay
• digit
• D-I-D-G-E-T
• A number
• thief
• T-H-E-F-E
• A person who takes things
• These are actual definitions

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The Role of RH in semantics

• Conceptual information, even for a single item,
  is widely distributed
• A network
• Occupies both hemispheres
• RH information is more connotative
• LH information more exact

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Connotative information in RH

• Tests on patients with isolated RH resulting from
  callosotomy
• RH has information about (many) nouns and verbs
• Not as many as in LH
• Semantic information differently organized in RH
• Zaidel (1990) the right hemisphere is
  characteristically connotative rather than
  denotative . The arcs of the semantic network
  connect more distant concepts and the
  organizing semantic relationships are more
  loosely associative and dependent on experience
  (125)

Baynes Eliason, The visual lexicon its access
and organization is commissurotomy patients (1998)
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Semantic information E.S.T. and J.G.

• Patient J.G. real definitions
• digit A number
• thief A person who takes things
• Patient E.S.T. connotative information
• snowman Its cold, its a ma cold frozen.
• stool seat, small seat, round seat, sit on
  the
• steak Im going to eat something its beef
  you can have a së different costs more

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Conclusion about E.S.T.

• RH semantic information is intact
• LH semantic information is wiped out
• Phonological information is spared in both
  hemispheres
• Question Why cant the RH semantic information
  be conveyed to LH phonology?

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Corpus Callosum(revealed by excision of top of
right hemisphere)
Corpus Callosum
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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Retrieval of words, meanings
• Communication between subsystems

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Mirror Neurons

• What makes them so smart?
• (already considered)
• Its a matter of hierarchical organization

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Implications of hierarchical organization

• Nodes at a high level in a hierarchy may give the
  appearance of being very smart
• This appearance is a consequence of their
  position at top of hierarchy
• As the top node in a hierarchy, a node has the
  processing power of the whole hierarchy
• Grandmother nodes
• Mirror neurons
• Compare
• The general of an army
• The head of a business organization

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Interpreting Linguistic EvidenceCareless
thinking and critical thinking

• Wernickes area and speech production
• Brocas area and speech production
• Brocas area and Wernickes area in syntax
• The meanings of words
• Mirror neurons very smart?
• Invoking the computer metaphor
• Representation of information
• Retrieval of words, meanings
• Communication between subsystems

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The brain and the computer
Conference abstract, March 28, 2009 Mark Jude
Tramo, MD PhD, Harvard, MIT, Mass Gen
Functional Brain Organization in Relation to
Emotion and Meaning in Music When we experience
the beauty of musicthere is no sound in our
brains. All acoustic information striking our
eardrums is transformed into neural information
represented by patterns of electrical activity
strings if 0s and 1s whose bits vary depending
on the pitch, loudness, duration, consonance, and
timbre of each note, harmonic interval, and
chord.
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Retrieval from memory

• inability to retrieve the word
• As if the word were stored in some kind of
  symbolic form in some memory location, from which
  it has to be retrieved
• Better inability to access the internal
  representation of the word

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Links for intermodal communication

• Examples
• Phonological grammatical semantic
• Phonological recognition phonological
  production
• I.e., Wernickes area and Brocas area
• Two related problems
• What information is transmitted?
• Over what kind of connection?

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Transmitting information

• For example,
• from angular gyrus to Wernickes area
• Conceptual or lemma inf in AG
• Phonological inf in Wernickes a.
• from Wernickes area to Brocas area
• Some kind of phonological information
• Some kind of code?
• Phonemic transcription?
• Phonological image in Wernickes a.
• Phonological motor program in Brocas a.

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What kind of connection?

• Two possibilities
• The way its done in computers
• Vector coding, a bus
• Only a few fibers needed
• But some means of coding is needed
• Local coding, individual connections
• A very large number of fibers needed
• By comparison, grossly inefficient

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Vector coding vs. Local coding

• Vector coding requires only a small bus
• A 32-bit bus can carry and of 232 items of
  information
• The way its done in personal computers
• Nowadays, many use a 64-bit bus
• Local coding requires a very large bus
• A separate fiber for each item
• For arcuate fasciculus, hundreds of thousands
• Anatomical evidence can provide answer
• How many fibers in arcuate fasciculus?

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Anatomical evidenceWernickes area and Brocas
area

• Connected by arcuate fasciculus
• Auditory phonological images linked to
  articulatory images
• Individual connections would require many
  thousands of fibers
• How many fibers in arcuate fasciculus?

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How many Fibers in Arcuate fasciculus?

• Selden (1985300) macroscopically most obvious
• Consists of axons of neurons distributed
  throughout Wernickes area
• Therefore, millions of fibers
• Different fibers originate in different locations
  throughout Wernickes area

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How many fibers in arcuate fasciculustheoretical
calculation

• From each minicolumn, at least one axon to
  Brocas area
• How many minicolumns in Wernickes area?
• 20 sq cm x 145,000 minicolumns per sq cm
• 2,900,000
• Therefore, at least 2,900,000 axons in arcuate
  fasciculus

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So what is the information that is sent?

• We have to avoid thinking of the brain as a
  computer
• An axon sends only one kind of information
• Activation
• Can come in different degrees
• i.e., different frequencies of firing
• Nothing else needed, since it is a unique
  connection
• This is a property of connectivity
• All the information is in the connectivity
• Connectivity rules!

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end