Structures and Functions of the Cerebral Cortex

Question 1

How is the Cerebral Cortex Organised?

3

Answer 1

• Primary Motor Cortex and Primary Sensory cortex
• each made up of 6 separate Laminae
• Each Laminae vary in thickness and prominence depending on the purpose they serve:
  eg: Laminae V = Muscle control => very thick in PMC
  Laminae IV = senses => thick in PSC but thin in PMC as it is less functional

Question 2

How are Laminae Organised?

5

Answer 2

• Stacked in columns
• Same function/ responding to the same stimuli cells arranged in the same column:

Macro-columns: General functions
Micro-columns: More specific functions

Question 3

What is Brodmann’s Brain Map?

3

Answer 3

• Cortex can be divided into many sub-regions depending on:

laminae thickness
Cell structures inside laminae

Question 4

What is the role of the Occipital Lobe?

6

Answer 4

• Primary Visual Cortex/ Striate Cortex
• Main target for axons from thalamic nuclei concerned with vision
• Destruction of striate cortex = cortical blindness in a related part of visual field

Question 5

What is the role of the Parietal Lobe?

6

Answer 5

• Integrates sensory and spatial information
• Damage = tactile function deficit, body image disorders, right-left confusion, spatial ability problems, sensory neglect

Question 6

What is the role of the Somatosensory Cortex?

2

Answer 6

Part of the Parietal Lobe

• different areas correspond to senses on different parts of the body

Question 7

What are the roles and functions of the Temporal Lobes?

7

Answer 7

They are highly connected to the other lobes, sensory and limbic systems and the basal ganglia

• Functions: Memory, emotion & mood, auditory & some visual perception

Question 8

How are the Temporal Lobes involved in memory?
Scoville and Miller 1957
(4)

Answer 8

Home of Hippocampus which is crucial for memory

• The case of HM: temporal lobe surgery for epilepsy damaged hippocampus
  HM’s intellect, personality and perception intact but unable to form new memories => Anterograde Amnesia

Question 9

How are the Temporal Lobes involved in Emotion and Mood?

3

Answer 9

Home of Amygdala

-Amygdala activated by emotional stimuli
- Amygdala damage = Inability to show
appropriate responses to stimuli
recognize other’s emotions

Question 10

How are the Temporal Lobes involved in Auditory (& visual) perception?
(6)

Answer 10

• The temporal lobes specialize in focusing attention on relevant auditory, information and perception of speech and music
• Damage to Wernicke’s Area = inability to understand words, or produce coherent speech => Wernicke’s Aphasia

Question 11

What what are the structures and role of the Frontal Lobes?

5

Answer 11

1. Primary Cortex
2. Premotor Cortex
3. Frontal and Prefrontal Cortex
4. Broca’s Area

• The FL act as a control center: receives input thalamic nuclei, limbic system, hypothalamus and other lobes

Question 12

What is the role of Broca’s Area?

3

Answer 12

• Related to fluency and understanding of speech

- Damage to Broca’s Area = comprehensive but effortful speech => Broca Aphasia

Question 13

What is the role of the Motor Cortex?

1

Answer 13

-Movement of different body areas through neural connections

Question 14

What is the role of the Frontal Cortex?

5

Answer 14

- Higher order cognitive processes
planning and evaluation
event monitoring
monitoring emotions
working memory
- 1/3 of the frontal lobe

Question 15

What did the case of Phineas Cage taught us about the Prefrontal Cortex? (Accidental Damage)
(2)

Answer 15

• Damage to it caused him problems with planing and abiding to social structures

Question 16

What did intentional damage to the prefrontal Cortex taught us about it?
(7)

Answer 16

• Prefrontal Lobotomies: Disconnection of the prefrontal cortex: in primates it made them tamer with few sides effects

-In humans: calmed people down but 
loss social inhibitions
loss emotional expression
\+ apathy 
inability to plan
problems with working memory