1. VCE Psychology Units 3 & 4
Chapter 4: Central nervous system
Brain structure and cognitive processes

2. Parts of the brain
The central nervous system is made up of many different components. The cerebral cortex is what we usually mean when we refer to the brain, but it is only one part.
This presentation will use structures and divisions to teach you about different brain functions.
There are different ways of approaching this.
Cerebellum
Midbrain
Spinal cord
Cerebral cortex
Sensory cortex: receives and processes information from our different senses.
Motor cortex: receives, processes and sends information about voluntary bodily movements.
Association areas: integrate sensory, motor and other information and are involved in more complex mental abilities.
Source: Brand X

3. Parts of the brain
If we were to view the brain from the top, it can be divided into left and right hemispheres.
These are joined together by a band of nerve tissue called the corpus callosum.
Source: Getty
Corpus callosum

4. Lobes of the cerebral cortex
Each hemisphere can also be divided into four lobes:
frontal lobe
parietal lobe
occipital lobe
temporal lobe.
The lobes contain areas of the cortex that specialise in particular functions.

5. Frontal lobe The frontal lobe:
includes the primary motor cortex which controls voluntary bodily movements
performs complex mental functions
is involved with attention, personality, control of emotions and expression of emotional behaviour
also contains Broca’s area, in the left hemisphere, which plays a crucial role in speech production.

6. Parietal lobe Parietal lobe:
includes the primary sensory cortex, which receives and processes sensory information
is also involved in attention and spatial reasoning
liaises with other lobes to allow us to sense the position of our body in space.
A huge part of the primary sensory cortex is devoted to sensations of the mouth and hands.

7. Temporal and occipital lobes
Temporal lobe:
contains the primary auditory cortex, which receives and processes sounds from both ears
is also involved in memory, visual perception, object identification and emotional responses to sensory information and memories
also contains Wernicke’s area, in the left hemisphere, which is crucial in speech comprehension.
Occipital lobe:
contains the primary visual cortex
is largely engaged in the sense of vision, but also interacts with other lobes to integrate visual information with other information, like memory, language and sounds.

8. Lobes of the cerebral cortex
Moving clockwise from the top, label each part of the brain. 1 2 10 3 4 9 5 8 7 6

9. Hemisphere specialisation
While both hemispheres are involved in almost all brain functions, hemispheres can exert greater control in clearly distinguishable functions.
Which do you think is your dominant hemisphere?
How could you test someone’s hemisphere specialisation?

10. RAS and thalamus
The reticular activating system (RAS) is a network of neurons that extends from the reticular formation to parts of the brain and spinal cord. It is largely responsible for our level of alertness.
The thalamus filters information from the senses and transmits that information to the cerebral cortex. It prioritises and filters this sensory information. Only smell has a direct route to the cerebral cortex.

11. The spinal cord
The spinal cord is made up of the column of nerve fibres from the base of the brain to the lower back. It receives sensory information from the body to transmit to the brain, and vice versa. It integrates the central nervous system and the peripheral nervous system.

12. Quick quiz
Question 1: What are the two cerebral hemispheres connected by?
Answer: The corpus callosum.
Question 2: Which parts of the body have the highest proportional representation on the primary sensory cortex?
Answer: The hands and the mouth.
Question 3: Where is Broca’s area located?
Answer: On the left frontal lobe.
Question 4: State three cognitive functions of the left hemisphere.
Answer: Language, analysis, logical reasoning, verbal skills.
Question 5: Which lobe contains the primary visual cortex?
Answer: The occipital lobe.
Question 6: What is the role of the temporal lobe?
Answer: It is largely involved in auditory processing, but it is also involved in memory, visual perception and emotional responses.
Question 7: Which sense bypasses the thalamus and goes directly to the cerebral cortex?
Answer: Smell.
Question 8: What two systems does the spinal cord integrate?
Answer: Central and peripheral nervous systems.