5. Language Comprehension

Question 1

Outline a study demonstrating the roles of the auditory cortex

Answer 1

(Scott et al., 2000)
• PET study to see which areas are active during speech/distorted speech
• Comprehensible speech activated the area outside of the auditory cortex and along the temporal lobe

Question 2

How has sparse imaging demonstrated auditory cortex activation?

Answer 2

(Davis and Johnsrude, 2003)
• MRI, sentences presented between scans
• Activation along length of superior temporal lobe, both anterior and posterior to auditory cortex- Peru-auditory areas: more activation to intelligible speech sounds
- hierarchical processing system- more distant areas involved in higher level aspects of comprehension

Question 3

Which areas were proposed for the processing of speech?

Answer 3

(Scott and Johnsrude,2003)
Anterior superior temporal

(Hickok and Poeppel, 2004)
Posterior inferior temporal

Question 4

What evidence is there for (Scott and Johnsrude, 2003)?

Answer 4

(Mummery et al., 2000)
VBM and semantic dementia patients
• 6 patients 
• VBM estimates grey matter in each voxel and compares to controls
—> left anterior temporal lobe affected

Question 5

What evidence is there for (Hickok and Poeppel, 2004)?

Answer 5

(Bates et al., 2003)
• Voxel-based lesion-symptom napping in stroke patients
• N=101
• Patients given scores and scores compared for each voxel between patients with and without damage
—> posterior temporal lobe importance

Question 6

How is syntax processed? Give evidence

Answer 6

LIFG

(Just et al., 1996)
• Number of voxels activated in LIFG increased with syntactic complexity. Compared to right as control

(Rodd et al., 2005)
• Sentences matched for syntactic complexity and other factors- ONLY differ in ambiguity
• High ambiguity activated more areas in both LIFG and peri-auditory cortex
• Only auditory cortex Involved in low ambiguity
—> LIFG important for all complex language processing

Question 7

Why is there inconsistency between (Gough et al., 2005) and (Rodd et al., 2005)

Answer 7

Rodd Found Activation of posterior LIFG due to semantic ambiguities which supposedly deals with sound
- phonological working memory may be required to resolve ambiguities

Question 8

How is the auditory cortex connected to LIFG?

Answer 8

(Catani, 2008)
• DTI Tractography to identify white matter pathways
- dorsal route through parietal lobe to posterior LIFG
- ventral route through temporal lobe to anterior LIFG
- much like reading