Lecture 11 - Human communication and language

Question 1

what are the major language centres in the brain responsible for?

Answer 1

• Wernicke and brocas - mediate language
• Somatosensory perception - e.g. braille
• Auditory perception
• Primary visual pereception
• these areas are all connected with wernickes/ brocas to understand and make speech/ language

Question 2

Define Aphasia

Answer 2

LOSS OR IMPAIREMENT OF LANGUAGE COMPREHENSION OR PRODUCTION

- not a problem with speech/ writing production appartus - due to brain centres

Question 3

What are the forms of aphasia

Answer 3

• Broca’s aphasi
• Wernickes aphasia
• Conduction aphasia
• Anomic aphasia

Question 4

What was Brocas case study about?

Answer 4

Patient ‘Tan’ - could only say tan

• autopsy revealed a large fluid filled cavity in left frontal lobe
• could comprehend but not produce speech
• speech is associated with left hemisphere

Question 5

Define Brocas (non-fluent) aphasia

Answer 5

Comprehension is in tact, but speech is slow, non-fluent, costs effort.
- Cant produce complete sentence structures
- content words still used (nouns/verbs)
but
- function words are not (a,the,in)
so its difficult to follow what they are saying (incomplete sentences)

Question 6

What are the causes of Brocas Aphasia?

Answer 6

Damage to INFERIOR LEFT FRONTAL LOBE and UNDERLYING SUBCORTICAL WHITE MATTER

• often due to stroke
• bottom left

Question 7

What test is used to test for aphasia?

Answer 7

Boston Diagnostic Aphasia test - Cookie theft picture

• have to exaplin whats going on in the situation
• gets a bit fluid at some points though due to automated phrases

Question 8

What are the 3 deficits of brocas aphasia?

Answer 8

1. Agrammatism - difficulty with grammatical constructions, word order
2. Anomia - trouble choosing/ findings words from memory
3. Articulation problems - controls muscles speech, mispronunciations of words

Question 9

What is intact in brocas aphasia?

Answer 9

• Phrases like yes or no - automatic
• Non-language expressions - automatic
• curse words- often due to frustrations with language, frontal area damage may also effect planning and organisation, may also inovlve right hem - inhibition and emotional aspects of language

Question 10

What are the other aspects of brocas?

Answer 10

• Patients often have apraxia of the left side - cant follow sequences of motor commands (motor areas near brocas, could also be damaged by stroke)
• Damage to motor central areas of left hemisphere -> causes extreme motor impairment (poor writing)
• Sensory areas in POSTERIOR BRAIN are usually intact

Question 11

Outline Wernickes (fluent )Aphasia

Answer 11

• 1874
• Have no comprehension of speech - cant repeat back (how you test for this)
• Speech it produced but is meaningless, yet fluent and unlabored (just ramble, loads of waffle)
• Unaware of condition unlike brocas

Question 12

Hows iw wernickes aphasia caused?

Answer 12

• Damage to MIDDLE AND POSTERIOR PORTIONS OF THE SUPERIOR TEMPORAL GYRUS (left hemisphere)

Question 13

What are the 3 speec deficits in wernickes?

Answer 13

1. Pure word deagness - cant recognise spoken word
2. Comprehension of word meaning - problems understanding, cant give definitions
3. Inability to convert thoughts into words

Question 14

Outline pure word deafness and neural basis

Answer 14

CAN recognive other sounds (doorbell)
CAN read and write, as well as lip read
CANNOT speak sensibly

Temporal lobe Auditory system of:
Left hem:
• recognition of short sounds (words)
• For longer sounds (prosody: intonation, rhythm, emphasis, emotional content)

Question 15

What areas of brain causes comprehension of word meaning trouble?

Answer 15

damage to POSTERIOR LANGUAGE AREA (junction of temporal/parietal/occipital)
Damage to this area alon causes TRANSCORTICAL SENSORY APHASIA

Question 16

outline transcortical sensory aphasia

Answer 16

Caused when POSTERIOR LANGUAGE AREA is damaged:
CAN repeat + recognise words
CANNOT understand meanings behind repetitions
CANNOT form meaningful speech on their own

Question 17

How is inability to convert thoughts into words caused?

Answer 17

Pure word deafness + Transcortical sensory aphasia = wernickes - can have them alone, depends on damage

Question 18

OUtline wernick geschwind model

Answer 18

1. Visual input to visual center (occipital lobe)
2. To wernickes area: formulate words
3. To brocas area: translate signal to motor commands - to muscles, for language expression
   - Other form of sensory iput goes to sensory association centres (parietal) which then follows same pathway

Argued for region specificity, so that in brocas, comprehension is largely fine and vice versa with wernickes

Question 19

Who investigated Werncikes aphasia in the brain?

Answer 19

karl lashely - argued its the amount you take out, not where you take it
HE WAS WRONG
- wernicke proved that there is localisatinon of function

Question 20

What are the brain areas involved in wernickes/ brocas aphasia

Answer 20

• THALAMUS - where vision terminates, relay station
• BROCAS AREA - planing speech, which muscles to mvoe
• WERNICKES - sounds put together into speech, and what it means
• PARIETAL-TEMPORAL-OCCIPITAL-ASSOCIATION cortex
• HIGHER ORDER VISUAL CORTICAL AREAS - forms words

Question 21

What are the rehabilitation techniques?

Answer 21

1. Imitating/ repeating sounds, following commands
2. Work on functinos they have retained - depends on ability level
3. Melodic - improve language skills with music
4. Alternative Augmentative communication (AAC) - hieroglyphic things (just SR in apes?)

Question 22

Define the types of conditions, like alexia and stuff

Answer 22

1. Apraxia = cant make movements
2. aphasia = cant speak
3. alexia = cant read
   - pure alexia = can write, but not read what you;ve written
4. agraphia = cant write

3 and 4 normally come together