Aphasia and Intelligence

Pierre MarieThey hear and comprehend all that one says to them; they all have their intelligence; they emit vocal sounds with ease; they execute with their tongue and their lips movements much more extensive and energetic than those required for the articulation of sounds, and yet the perfectly sensible response that they would want to make is reduced to a very small number of articulated sounds, always the same and always performed in the same manner; their vocabulary, if we can call it that, is composed of a short series of syllables, sometimes of a monosyllable that expresses everything, or rather that expresses nothing, for this unique word is most often a stranger to all vocabularies.

Paul Broca

QUestion 1(review)

Which component or components represent the form of a word?

a) Centre A onlyB) CENTRE M ONLYC) CENTRES A AND MD) CENTRES A, M AND IDEATION.

There are no language centres!“The third left frontal convolutionplays no special role in language”

I deny that there exists in the left hemisphere a verbal auditory sensory centre localized either in the foot or in the middle part of the first temporal lobe.

I deny that there exists in the foot of the third left frontal convolution a verbal motor centre.

“Of the three unequal pieces ofpaper placed in this table: you willgive me the largest one, you willcrumple the middle-sized one andthrow it down, and as for the smallestone, you will put it in your pocket”

MARIE PAPER TEST

“The physician must pantomimethe different parts of the order,and then tell the patient to reproducethe series of acts which he has just seen. In severe cases (...of aphasia...)the patient is generally incapable of carrying out this task in full”.

“In the case of aphasia there issomething much more importantand much more grave than the loss ofthe meaning of words; it is a very marked diminution in intellectualcapacity in general”.

Marie was arguing that left hemisphere damage did not impair language but intelligence.

The problem of ‘mere associations’

Language impairment Language + other impairments

No better example could be chosen of the manner in which the writers of that period were compelled to lop and twist their cases to fit the procrustean bed of their hypothetical conceptions.

QUESTION 2

“PROCRUSTEAN” MEANS:

A) Enforcing uniformity without regard to lawful variation or individual differencesB) The claim that language centres are all localizable to specific regions of the brainc) The claim that language can be understood by meansof abstract diagrams

The term ‘procrustean’ means ‘enforcing uniformity without regard to lawful variation or individual differences’. And it is true if you think about the problem, that the diagrams were intended to represent a universal architecture of the brain that was the same from person to person. Is this biologically plausible, especially when it is generally true that neurological damage never produces exactly the same profile of impairments across individuals? How do we theoretically interpret a very unusual pattern of deficits in the language domain? Should we assume that one case provides evidence for a general theory that applies to all brains or is there variation in the way language architectures might develop between individuals? PAGE

35

No better example could be chosen of the manner in which the writers of that period were compelled to lop and twist their cases to fit the procrustean bed of their hypothetical conceptions.

QUESTION 2

“PROCRUSTEAN” MEANS:

A) Enforcing uniformity without regard to lawful variation or individual differences **B) The claim that language centres are all localizable to specific regions of the brainc) The claim that language can be understood by meansof abstract diagrams

The diagrams were intended to represent a universal architecture of the brain that was the same from person to person.

Is this biologically plausible, especially when it is generally true that neurological damage never produces exactly the same profile of impairments across individuals? How do we theoretically interpret a very unusual pattern of deficits in the language domain?

Should we assume that one case provides evidence for a general theory that applies to all brains or is there variation in the way language architectures might develop between individuals?

This kind of functionalarchitecture...

....Enforces uniformity without regard to lawful variation or individual differences

PHONOLOGICAL AND SURFACE DYSLEXIA TOGETHER MAKEUP A DOUBLE DISSOCIATION BETWEEN THE LEXICAL ANDNON-LEXICAL READING ROUTE.

THE EXISTENCE OF THESE TWO READING DISORDERS PROVIDESEVIDENCE THAT THESE TWO ROUTES FROM PRINT TO SOUNDARE SEPARATE FUNCTIONAL COMPONENTS (MODULES) OF THE READING SYSTEM.

ANOTHER WAY TO STATE THIS IS THAT THE LEXICAL AND NON-LEXICAL READING ROUTES ARE DOUBLY DISSOCIABLE.

QUESTION 3

ACCORDING TO THE DIAGRAM OF THE READING SYSTEM:

PATIENTS WITH SEVERE DAMAGE TO THE SEMANTIC SYSTEM WHO WEREFULLY LITERATE BEFORE THE DAMAGE, SHOULD STILL BE ABLE TO READ EXCEPTION WORDS LIKE ACHE, BEAD, PINT AND LEOPARDCORRECTLY, EVEN THOUGH THEY NO LONGER UNDERSTAND THE MEANINGOF THESE WORDS

A) TRUEB) FALSE

QUESTION 3

ACCORDING TO THE DIAGRAM OF THE READING SYSTEM:

PATIENTS WITH SEVERE DAMAGE TO THE SEMANTIC SYSTEM WHO WEREFULLY LITERATE BEFORE THE DAMAGE, SHOULD STILL BE ABLE TO READ EXCEPTION WORDS LIKE ACHE, BEAD, PINT AND LEOPARDCORRECTLY, EVEN THOUGH THEY NO LONGER UNDERSTAND THE MEANINGOF THESE WORDS

a)TRUE **• FALSE

QUESTION 4

IN FACT THOUGH, MANY PATIENTS WITH DEMENTIA (AND SEVERESEMANTIC IMPAIRMENT) DO HAVE DIFFICULTY READINGEXCEPTION WORDS. THUS — SURFACE DYSLEXIA IS QUITE COMMONIN PATIENTS WITH ALZHEIMER’S DISEASE AND SEMANTIC DEMENTIA WHOPREVIOUS TO THEIR DEMENTIA WERE FULLY LITERATE.

a)TRUE b)FALSE

Consider the following result: Many patients with dementia (for example, in cases of Alzheimer’s disease, or in cases of semantic dementia) have semantic impairments (in the Wernicke-Lichtheim diagram, Ideation is impaired). That is, word meaning is impaired. Such patients generally also have difficulty reading words with irregular spelling-to-sound patterns (for example, dough, colonel, yacht). The worse the comprehension impairment in dementia, the poorer the ability of the patient to correctly read orthographically irregular words aloud.

PAGE 35

QUESTION 4

IN FACT THOUGH, MANY PATIENTS WITH DEMENTIA (AND SEVERE

SEMANTIC IMPAIRMENT) DO HAVE DIFFICULTY READINGEXCEPTION WORDS. THUS — SURFACE DYSLEXIA IS QUITE COMMON

IN ALZHEIMER’S DISEASE AND SEMANTIC DEMENTIA.

a)TRUE ** b)FALSE

QUESTION 5

BUT OCCASIONALLY, SOME PATIENTS WITH DEMENTIA (AND SEVERESEMANTIC IMPAIRMENTS) HAVE NO DIFFICULTY READINGEXCEPTION WORDS. IN THESE PATIENTS, READING EXCEPTION WORDSIS INTACT (NORMAL) DESPITE SEVERE IMPAIRMENT TO THE SEMANTICSYSTEM.

a)TRUE b)FALSE

QUESTION 5

BUT OCCASIONALLY, SOME PATIENTS WITH DEMENTIA (AND SEVERESEMANTIC IMPAIRMENTS) HAVE NO DIFFICULTY READINGEXCEPTION WORDS. IN THESE PATIENTS, READING EXCEPTION WORDSIS INTACT (NORMAL) DESPITE SEVERE IMPAIRMENT TO THE SEMANTICSYSTEM.

a)TRUE **b)FALSE

Consider the following result: Many patients with dementia (for example, in cases of Alzheimer’s disease, or in cases of semantic dementia) have semantic impairments (in the Wernicke-Lichtheim diagram, Ideation is impaired). That is, word meaning is impaired. Such patients generally also have difficulty reading words with irregular spelling-to-sound patterns (for example, dough, colonel, yacht). The worse the comprehension impairment in dementia, the poorer the ability of the patient to correctly read orthographically irregular words aloud.

The problem of associations of impairments

Except for the undeniable fact that occasionally a patient with severe dementia shows no such reading impairment; irregular words, even uncommon words like jeopardy, tortoise, and pharaoh are read aloud correctly, even though the patient no longer retains any grasp of their meaning.

Which result do we use to draw a conclusion about the functional architecture of the reading mechanism:

(i) The overwhelming majority of cases who show an association between impaired comprehension and reading aloud or

(ii) the handful of patients who show a dissociation?

General Atrophy in dementia affects the whole system

Atro

phy

Atro

phy

Atro

phy

Atro

phy

Atro

phy

Atro

phy

Atro

phy

Atro

phy

The alternative