Lecture 14 Language (Layla)

Question 1

Which aphasia is limited to production of mainly verbs and nouns?

Answer 1

Broca’s (Expressive) Aphasia.

have trouble speaking fluently but their comprehension can be relatively preserved. …

difficulty producing grammatical sentences and their speech is limited mainly to short utterances of less than four words.

Question 2

When did Paul Broca encounter his “area”?

Answer 2

1865

Question 3

Which area is damaged in Broca’s aphasia?

(area and BA)

Answer 3

Damage to

Inferior frontal gyrus

(BA 44/45)

Question 4

Broca’s aphasia is nota problem controlling vocal muscles

Why?

It is nota problem related to general intelligence

Why?

Answer 4

Can blow out candles

Clear one’s throat

Scores on non-verbal tests are normal

Calculation, map reading, facial recognition

Can carry out verbal commands

Question 5

When did Carl Wernicke discover his “area”

Answer 5

1874

Question 6

Where is wernicke’s area?

Answer 6

left temporal lobe

Question 7

Which aphasia are patients generally unaware of their deficit?

Answer 7

Wernicke’s

[Loss of ability to comprehend words, speech remains fluent but nonsensical (word salad)]

Question 8

Where is Wernicke’s area?

Answer 8

It is traditionally thought to be in Brodmann area 22, which is located in the superior temporal lobe in the dominant cerebral hemisphere

Question 9

percentage of people with left/right hemisphere dominance

Answer 9

the left hemisphere in about 95% of right handed individuals and 60% of left handed individuals).

Question 10

what is fluent aphasia?

Answer 10

Damage caused to Wernicke’s area results in receptive, fluent aphasia. This means that the person with aphasia will be able to fluently connect words, but the phrases will lack meaning.

Question 11

What is non-fluent aphasia?

Answer 11

non-fluent aphasia, in which the person will use meaningful words, but in a non-fluent, telegraphic manner.

(Expressive; Broca’s)

Question 12

Broca’s Aphasia summary

Answer 12

Left frontallobe damage

Speech production deficits

Comprehension spared

Paraphasicerrors of letters and/or words

Question 13

Wernicke’s Aphasia Summary

Answer 13

Left temporallobe damage

Speech production spared

Comprehension deficits

Severe paraphasicerrors

Neologisms: Not a real word, but sounds like one

e.g.,) biznit, scrut, almod

Question 14

What is conduction aphasia?

Answer 14

Inability to transfer information between Broca’s and Wernicke’s areas

Arcuate fasciculus –white matter tract connecting Broca’s and Wernicke’s area

Question 15

Which aphasia is repetition impaired?

Answer 15

Conduction Aphasia

Production is intact (no damage to Broca’s)

Comprehension is intact (no damage to Wernicke’s)

Just Repetition impaired:

disconnect between how sounds map on to words and how to produce those sounds

Question 16

What is Anomic Aphasia?

Answer 16

Impairment in word-finding and naming

Question 17

3 types of Anomic Aphasia

Answer 17

(Anomic Aphasia: Impairment in word-finding/naming)

1. Word selection anomia

Correctly selects target in group, but cannot name it

2. Semantic anomia

Unable to select the correct object from a group of objects, even when provided with the name of the target object

3. Disconnection anomia

Modality-specific impairments

Question 18

What is Transcortical Motor Aphasia?

Answer 18

Similar in presentation to Broca’s Aphasia

Normal (spontaneous) speech production is impaired

Echolalia –compulsion to repeat something just heard

Repetition of words or phrases is normal

TMoA is generally characterized by reduced speech output, which is a result of dysfunction of the affected region of the brain. The left hemisphere is usually responsible for performing language functions, although left-handed individuals have been shown to perform language functions using either their left or right hemisphere depending on the individual.

Transcortical motor aphasia is a rare syndrome that is due to a small subcortical lesion superior to Broca’s area or to a lesion outside of the anterior language areas of the left hemisphere

Question 19

What is Transcortical Sensory Aphasia?

Answer 19

Similar presentation to Wernicke’s aphasia

Word salad

Paraphasias

Neologisms

Comprehension impaired

Repetition is spared, often see echolalia

Damage to angular gyrus most often, also frontal or thalamic lesions

Question 20

What is Pure Word Deafness?

Answer 20

Inability to comprehend speech

Hear spoken language as meaningless noise (foreign language)

Reading, writing, speech production, and naming intact

Bilateral superior temporal lobe lesions (some parietal involvement)

Question 21

Question 22

2 Routes for Reading

Answer 22

Phonological Method:

CAT = /c/ /a/ /t/

Grapheme-to-phoneme correspondence rules. (graphemes = smallest units of written language, e.g., letters)

“Hukt awn fonix werkt fur me”

Whole-Word Method:

Direct route

Go directly from orthography (the structure of the printed word)to meaning

Irregular words (yacht, colonel) can only use direct route

Question 23

Whole-Word Method

Answer 23

Aoccdrnigto a rscheearchat CmabrigdeUinervtisy, it deosn’t mttaerin wahtoredrthe ltteersin a wrodare, the olnyiprmoetnttihngis tahtthe fristand lsatltteerbe at the rghitpclae. The rsetcan be a toatlmsesand you can sitllraedit wouthitporbelm. Tihsis bcuseaethe huamnmniddeosnot raederveylteterby istlef, but the wrodas a wlohe.”

Question 24

Disorders of Visual Language: Alexia

Answer 24

Inability to read following brain damage

Co-occur when there is damage to angular gyrus

Alexia and agraphia are doubly dissociable:

e.g.,) Can write a sentence and unable to read it or can read a sentence but be unable to write it

Question 25

Disorders of Visual Language: Agraphia

Answer 25

Inability to write following brain damage

Co-occur when there is damage to angular gyrus

Alexia and agraphia are doubly dissociable:

e.g.,) Can write a sentence and unable to read it or can read a sentence but be unable to write it

Question 26

Phonological Alexia

Answer 26

Inability to map graphemes onto phonemes

No difficulty reading familiar regular words or irregular words, but cannot read unfamiliar words or non-words

E.g., won, one, wun

Inability to map graphemes onto phonemes

Damage to posterior inferior temporal lobe

Question 27

Surface Alexia

Answer 27

Disruption of ‘whole-word’/sight reading

Impaired reading of irregular words (e.g., one)

Reading of regular words and non-words is preserved (e.g., won, wun)

Damage to the parieto-occipital junction

Question 28

2 Routes for Writing

Answer 28

Two routes (analogous to reading):

1) Thought to semantics to writing (writing from memory)
2) Grapheme to phoneme correspondence rules (“sounding out” to write)

Question 29

Phonological Agraphia

Answer 29

Inability to write a word by sounding it out (e.g., non-words or unfamiliar words)

Preserved ability to write both familiar regular and irregular words

Damage to posterior parietal lobe, supramarginal gyrus (near Wernicke’s area) and angular gyrus

Question 30

Surface Agraphia

Answer 30

Inability to write irregular words (e.g., yacht)

Preserved ability to write regular words or non-words by sounding them out

Damage to parieto-occipital junction

Close to visual cortex (needed to go from word meaning directly to word form)

Question 31

Presurgical fMRI and DTI

Answer 31

Use fMRI to localize function near the resection

Tool for neuronavigation

Tractography(e.g., DTI) for mapping white

matter tracts

Remove as much affected tissue as possible, while preserving essential functions

Question 32

Functional Areas of cerebral cortex

Answer 32

Question 33

Layla’s

Take Home Message

Answer 33

Variety of ways in which language can be altered following brain injuries

E.g.,) Aphasia, alexia, agraphia

Both reading and writing can have impairments to ‘phonological’ or ‘whole-word’ processes

I.e.,) Sounding out vs. sight vocabulary

fMRI and DTI valuable for presurgical planning in patients undergoing neurosurgery procedures