4. Language In The Brain

Question 1

Where is Broca’s area and what is it linked to?

Answer 1

Inferior frontal gyrus

Speech production

Question 2

Where is Wernicke’s area and what is it linked to?

Answer 2

Superior temporal gyrus

Speech comprehension

Question 3

Outline the Neurological model of language and it’s criticisms

Answer 3

Speech input
Superior temporal gyrus
Inferior frontal gyrus
Motor output

(Freud, 1891)- against localisation- distinction between path and phys

(Marie, 1906)- Broca’s lesions don’t always affect speech and motor aphasia can result from lesions elsewhere

Question 4

What is lesion deficit mapping?

Answer 4

Neurosurgeons in 1980s

Question 5

What did neuroimaging show about Broca’s area? Cite reference

Answer 5

Meaning activates anterior and ventral Broca’s
- synonym task
Sound activates posterior and dorsal Broca’s
- homophone task

Similar experiments showed the same
(Fiez, 1997)

-> gets around Freud argument

Question 6

Outline a study that untangles Broca’s area

Answer 6

(Gough et al., 2005)
• TMS stimulation of anterior and posterior parts of Broca’s
• Reaction times:
- stimulate anterior part- 10% slower at semantic task, same at phonological
- stimulate posterior part- same at semantic task, 5% slower at phonological

Question 7

What causes conduction aphasia?

Answer 7

Damage to arcuate fasciculus:

• white matter pathway connecting superior temporal gyrus to inferior frontal gyrus
• unable to repeat words

Question 8

How can Broca’s area be subdivided?

Answer 8

Pars opercularis (44)
Pars triangularis and orbitalis (45)

Compare cytoarchitechtures- cell arrangements/density
- differs between areas

(Amunts et al., 1999)- used density profiles to measure changes in laminar patterns
- intersubject variability in cytoarchitechture was greater than within subject between 44 and 45

Question 9

What pathways connect from Broca’s?

Answer 9

SLF/AF from temporal parietal junction

UF from temporal poles

(Petrides and Pandya, 2009)- macaques histochemical track tracing
Showed white matter pathways

Question 10

How can SLF and UF be shown in humans?

Answer 10

Diffusion weighted MRI

Petrides and Pandya, 2012

Question 11

What does the anterior part of temporal lobe do?

Answer 11

Temporal poles:

Damage causes semantic dementia- progressive atrophy of anterior temporal lobe

Question 12

Summarise language in the brain

Answer 12

• Semantics brought in from anterior temporal lobe to Anterior LIFC via UF
• Sounds brought in from temporal parietal junction to posterior LIFC via SLF
• Integration of inputs