Neurobiology of language

Question 1

Describe the basics network underlying speech production and comprehension.

Answer 1

Speech production: Broca’s area (left inferior frontal gyrus)

Speech comprehension: Wernicke’s area (superior temporal region)

Question 2

Describe acquired language disorders from lesions to the left hemisphere.

Answer 2

• Damage to the more frontal areas: more related to motor/production problems
• Damage to the more temporal areas: more related to comprehension problems
• Lesions that do not hit the arcuate fasciculus, Broca’s- or Wernicke’s area will have intact repetition

Question 3

Describe Broca’s aphasia.

Answer 3

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

Question 4

Describe Wernicke’s aphasia.

Answer 4

Language deficit associated with comprehension impairment

Question 5

Describe global aphasia.

Answer 5

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

Question 6

Describe conduction aphasia.

Answer 6

Impairment of acurate fasiculus (the parietal connections between Broca’s and Wernicke’s area) –> problems with repetition, but not speech production or comprehension

Question 7

Describe transcortical aphasia (motor).

Answer 7

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

Question 8

Describe lateralization of language function.

Answer 8

• 95 % of right handed people are left hemisphere dominated
• 19 % of left handed people are right hemisphere dominated
• in some cases the right hemisphere can take over the basic language function if the left is damaged (children with epilepsy) –> bilateral activation for language in early childhood, and then lateralized later on

Question 9

Describe transcortical aphasia (sensory).

Answer 9

• 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 10

Describe Anomia Aphasia.

Answer 10

• Difficulty with word finding and naming items (spoken or writing)
• Speech is fluent and grammatically correct
• Good comprehension
• Often use vague words for or describe things they can’t name

Question 11

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

Answer 11

Prosody (modulation of pitch, intonation, melody, loudness, cadence, tempo, stress, accent and pauses)

Question 12

What are the key distinguishing features of the transcortical aphasias from the others?

Answer 12

• leisons are outside of the arcuate fasciculus, Broca’s-, and Wernicke’s area ==> repetition remains intact

Question 13

Describe the recovery of left hemiphere strokes in adults.

Answer 13

-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 14

Is the right hemisphere mediating recovery after left hemisphere stroke?

Answer 14

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 15

What is Aprosodia?

Answer 15

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

Question 16

Describe transcortical aphasia (mixed).

Answer 16

• Type of non-fluent aphasia
• good repitition
• imparied comprehension