Neurobiology of language

Question 1

What are the classical area of the brain associated with speech production?

Answer 1

Broca’s area (left inferior frontal gyrus)

Question 2

What are the classical area of the brain associated with speech comprehension?

Answer 2

Wernicke’s area (superior temporal region)

Question 3

What are Broca’s Aphasia?

Answer 3

A language disorder –> broken speech, inability to find words

Question 4

What are Wernicke’s Aphasia?

Answer 4

Language deficit associated with comprehension impairment

Question 5

Describe the Wernicke-Geschwind model.

Answer 5

We repeat something we hear: the auditory info arrives in the auditory cortex –> Wernicke’s area (understood as meaningfull words) -(via the acurate fasciculus)-> Broca’s area (converted to speech)

Question 6

What is Conduction Aphasia?

Answer 6

Impairment of acurate fasiculus –> problems with repetition, but not speech production or comprehension

Question 7

What is Global Aphasia?

Answer 7

Impairment of Broca’s, Wernicke’s area and acurate fasiculus

Question 8

Is the Wernicke-Geschwind model still the best model?

Answer 8

No:
- sensory infor can come directly into Broca’s area
- speech can be disturbed outside of those regions

Question 9

Which other models are there?

Answer 9

Two sets of dorsal pathways: one for speech production and repeating, another for processing complex syntax
Ventral pathways: takes the sound, and extract the meaning

Question 10

What are Transcortical Motor Aphasia (TMA)?

Answer 10

• A type of non-fluent aphasia
• good repetition
• comprehension are relatively normal
• damage to frontal areas close to Broca’s area

Question 11

What are Transcortical Sensory Aphasia (TSA)?

Answer 11

• a type of fluent aphasia
• trouble naming things
• good repetition
• impaired comprehension
• deficits in sematic retrieval
• damage to temporal areas close to Wernicke’s area (inferior)

Question 12

What are Anomia Aphasia?

Answer 12

• difficulity with word finding and naming items
• speech is fluent and grammatically correct
• good comprehension
• often use vague words for or describe things they can’t name
• damage to

Question 13

What does TMA, TSA and AA have in common?

Answer 13

• All occur with damage to regions close to, but outside of Broca’s or Wernicke’s area
• Repetition remains intact

Question 14

How many of right-handed people have left hemisphere dominance?

Answer 14

app. 95 %

Question 15

How many of left-handed people have right hemisphere dominance?

Answer 15

app. 19 %

Question 16

What function does the right hemisphere primarily contribute to (speech)?

Answer 16

Prosody

Question 17

What is prosody?

Answer 17

Modulation of pitch, intonation, melody, loudness, cadence, tempo, stress, accent and pauses

Question 18

Describe the general development of language.

Answer 18

In very young children language is bilateral, and then it is lateralized in adults

Question 19

Describe the recovery of left hemiphere strokes in adults.

Answer 19

• Acute phase (0-3 weeks): spontaneous recovery is mainly due to successful reperfusion and a decrease in cerebral edema and inflammation
• Sub-acute phase (<6 months): plastic changes in the brain occur along with the restoration of diaschisis
• Chronic phase (>6 months): recovery is mostly therapy related

Question 20

Is the right hemisphere mediating recovery after left hemisphere stroke?

Answer 20

The general consensus is that the recovery mostly comes from functional activation of perilesional areas or areas in the left hemisphere that also support language functions

Question 21

Describe the fenotype of a split brian patient.

Answer 21

• can repeat or describe words presented to right visual field
• can describe object manipulate by rigth hand
• if presented to left visual field cannot do the same (right hemisphere), cannot verbally describe
• cannot describe anything to left of their visual fixation point, but can indicate images non-verbally
  –> like two independently functional brains

Question 22

What is Aprosodia?

Answer 22

Loss of affective-prosodic aspects of language following focal right damage