Higher Cortical Function

Question 1

Outline the structure of the cerebral cortex

Answer 1

arranged as 6 laters containing cell bodies + dendrites (grey matter)

Question 2

What are most of the outputs of the cortex from?

Answer 2

Axons of pyramidal neurones

Question 3

Three types of output fibres

Answer 3

• Projection fibres: from cortex to brainstem
• Commissural fibres: between hemispheres
• Association fibres: connecting nearby regions of cortex in same hemisphere

Question 4

Where are most of the inputs to the cortex from

Answer 4

Thalamus
Other cortical areas

Question 5

Function of frontal lobe

Answer 5

• voluntary motor control
• expression of speech (left)
• behavioural regulation
• cognition
• eye movements
• continence

Question 6

Function of parietal lobe

Answer 6

• somatosensory perception
• comprehension of speech (left)
• body image (right)
• spatial awareness
• calculation + writing

Question 7

Function of temporal lobe

Answer 7

• hearing
• smell
• taste
• memory
• emotion
• long term memory
• comprehension of speech (left)
• emotion at limbic system

Question 8

What hemisphere is dominant in most people?

Answer 8

Left

Question 9

What is the left hemisphere dominant for?

Answer 9

Language
Mathematical/logical function

Question 10

What is the right hemisphere dominant for?

Answer 10

Body image
Visuospatial awareness
Emotion
Musical ability

Question 11

Where are the language pathways dominants?

Answer 11

Left hemisphere

Question 12

What is involved in language pathways + their function?

Answer 12

• Broca’s area: production of speech
• Wernicke’s area: interpretation of language
• arcuate fasciculus: connects the two

Question 13

Pathway for repeating a heard word

Answer 13

left hemisphere
- auditory cortex in temporal lobe
- signal sent to wernicke’s area
- signal to Broca’s area via arcuate fascicilus
- signal sent to primary motor cortex to elicit speech

Question 14

Pathway for speaking a written word

Answer 14

• left hemisphere
• visual cortex in occipital lobe
• signal sent to wernicke’s area
• signal to Broca’s area via arcuate fascicilus
• signal sent to primary motor cortex to elicit speech

Question 15

Location of Broca’s area

Answer 15

Inferior lateral frontal lobe

Question 16

Location of Wernicke’s area

Answer 16

Superior temporal lobe

Question 17

What can damage to Broca’s area cause?

Answer 17

Expressive aphasia
Staccato speech
Patient will still understand what is being said to them but can’t speak properly

Question 18

What can damage to Wenicke’s area cause?

Answer 18

Receptive aphasia
Fluent, nonsensical speech
But patient doesn’t appear to understand what is being said to them

Question 19

What does damage to the arcuate fasciculus cause?

Answer 19

Inability to repeat heard words

Question 20

What are the types of memory?
What do they store and where?

Answer 20

• declarative/explicit: factual information in cerebral cortex
• non-declarative/implicit: motor skills + emotion in subcortical structures e.g. basal ganglia + cerebellum
• short term memory: in cortical circuits
• long term memory: in cerebral cortex, cerebellum

Question 21

What does declarative/explicit memory store + where?

Answer 21

Factual information
In cerebral cortex

Question 22

What does non-declarative/implicit memory store + where?

Answer 22

• Motor skills + emotion
• stored in subcortical structures e.g basal ganglia + cerebellum

Question 23

Where is short vs long term memory stored?

Answer 23

• short: in cortical circuits
• long: in cerebral cortex, cerebellum

Question 24

What is consolidation?

Answer 24

Process of converting short term memories into long term memories

Question 25

What factors influence consolidation?

Answer 25

- emotional context - rehearsal - association

Question 26

Location of hippocampus

Answer 26

Deep in temporal lobe

Question 27

Function of hippocampus

Answer 27

Facilitates consolidation of memories in cortex via its output pathways

Question 28

Outline the main output pathway of the hippocampus

Answer 28

Fornix > mammillary bodies > thalamus > cortex

Question 29

What is the key molecular mechanism of memory consolidation?

Answer 29

Long term potentiation

Question 30

Role of long term potentiation in memory consolidation

Answer 30

- Causes changes in glutamate receptors in synapses - Leads to synaptic strengthening

Question 31

What is alien hand syndrome?

Answer 31

When one hand has a ‘mind of its own own’ and is not controlled properly by the brain

Question 32

What causes alien hand syndrome?

Answer 32

Damage in corpus callosum

Question 33

What is aphasia?

Answer 33

Acquired disorder of language resulting from brain damage to dominant hemisphere

Question 34

What is dysarthria?

Answer 34

Form of motor speech disorder which involves the abnormal articulation of sounds affecting speed, strength, timing, range + accuracy of movements

Question 35

What can damage to corpus callosum cause?

Answer 35

Alien hand syndrome Effects on language processing

Question 36

What can cause global aphasia?

Answer 36

Middle cerebral artery stroke

Question 37

What do the inferior and superior division of MCA supply?

Answer 37

**superior** - Broca’s area **inferior** - Wernicke’s area