1. The Localization of Function of the Brain
The IB syllabus says: Explain One Study Related to Localization of Function of the Brain
In IB speak
This means:

2. The structure and function of the brain
The brain is the seat of awareness and reason, where learning, memory and awareness are centered
It decides whether decisions were right or wrong, and imagines how things might have turned out if we had acted differently
The ‘crowning glory’ of millions of years of evolution – as new structures evolve, older structures are retained.
There are three layers that have evolved in different stages of evolution
1) the primitive central core
2) the limbic system
3) the cerebral hemispheres – which are in charge of higher mental processes

3. The Central Core
The point where the brain enters the scull is known as the hindbrain – the earliest part of the brain to evolve
It contains the Medulla which regulates bodily functions such as breathing, heart rate and blood pressure
This is also where nerves from the body cross from the left and right side of the brain on their way to and from the higher brain centers and vise versa
This is also where the cerebellum is located – which is responsible for our sense of balance to ensure movements go together in efficient sequences. Damage to the cerebellum causes severe problems in movement, such as jerky motions or stumbling.

4. The Central Core
Above the Cerebellum, the brain stem widens to form the midbrain.
This is where the Thalamus is – the relay station for all sensory information from the lower parts of the CNS – all information passes through the thalamus on the way to higher levels of the brain
Below is the Hypothalamus which plays an important role in releasing hormones and controlling body temperature, hunger thirst, heart rate and blood pressure.
Below the thalamus is the pituitary gland is the master gland and secretes hormones into to body regulating homeostasis (regulating the internal environment so as to maintain a stable, constant condition), and also playing an important role in the stress response system.

5. The Central Core Questions
In evolutionary terms, is this the most primitive or most recent part of the brain to evolve?
What does the Medulla do?
What happens to the nerves of the body in the central core?
What does the cerebellum do? What happens if this area is damaged?
What does the hypothalamus do?
What does the pituitary gland do? What is homeostasis?

6. The Limbic System
This is between the central core and the cerebral hemispheres
In evolutionary terms this is more recent than the central core and only fully developed in mammals which are more flexible in their responses to the environment – this suggests that the limbic system suppresses some instinctive behavior.
The Hippocampus plays a central role in the formation of new memories, and the transfer of memories from STM to LTM, damage to the hippocampus can result in anterograde amnesia (HM, Clive Wearing). Animals with damage to the hippocampus fail to recognize where they have been and explore the same part of their environment over and over again.
The Amygdala governs emotions related to survival and self preservation. If the Amygdala is removed in an aggressive animal, it becomes tame and docile, and stimulation to this area can trigger fear and panic (MacLean 1970)
Feelings of pleasure are also associated with the limbic system. If given the opportunity to press a bar connected to an electrode which stimulates a portion of the Septum, animals will do so endlessly, ignoring food and water.
The limbic system appears to play an important role in times of stress, and coordinating and integrating the activity of the nervous system.

7. The Limbic System

8. The Limbic System Questions
Where is the limbic system located?
In evolutionary terms, is it more or less recent than the central core?
What does the hippocampus do? How do we know this?
What does the Amygdala do?
What did MacLean (1970) find happens to animals with damaged amygdalas?
What is the septum associated with?

9. The Cerebral Cortex
Covering the central core and the limbic system is the cerebral cortex
The cerebrum is divided into two hemispheres covered in a thin layer of gray matter called the cerebral cortex
This is the part of the brain that processes thought, vision, language, memory and emotions.
It accounts for 80% of the weight of the human brain containing about 70% of the neurons in the CNS. Its the most recently evolved part of the nervous system and more developed in humans than in any other animal
Rats for example have a small smooth cerebral cortex, but higher mammals such as primates have a larger wrinkled cortex (this adaptation allows more cortical tissue to fit into the skull without producing a ‘swelled head’)

10. The Cerebral Cortex
The Primary Somatosensory Cortex receives messages from the body
The Primary Motor Cortex sends messages to the muscles and various glands in the body.
The four main lobes also have ‘Association Areas’ which integrate information from the different parts of the cortex.

11. The Cerebral Cortex Questions
What does this part of the brain process?
How much of the weight of the human brain does this area account for?
How much of the CNS neurons are contained in this area?
Why is the cerebral cortex wrinkled?
What does the Primary Somatosensory Cortex do?
What does the Primary Motor Cortex do?
What do the association areas do?

12. The Lobes of the Cerebral Cortex
The Occipital Lobe – Receives and processes visual information. Damage to this area can produce blindness, even though the eyes and their neural connections to the brain are healthy and intact
The Temporal Lobe – Plays an important role in complex visual tasks such as recognizing faces. Information is also processed from the ears and it contributes to balance and equilibrium and regulates emotions and motivations such as anxiety, pleasure and anger. The left temporal lobe is responsible for language and speech (Brocas area).
The Parietal Lobe – receives and processes sensory information from all over the body, from sense receptors in the skin (e.g. pain receptors), muscles, joints and taste buds.
The Frontal Lobe – accounts for about half of the volume of the brain, and is the most mysterious part of the brain, it receives, integrates and processes information about what is going on in the other parts of the brain.
Its been called the ‘executive control centre’ for the brain.
It is also involved in problem solving tasks.
The prefrontal cortex is involved in behaviors we associate with personality, such as motivation, persistence and character – we know this from the case of Gage 1848.
Biopsychologists support this with research hundreds of years later- damage to this area leads to changes personality – people who have this area damaged, tend to accumulate debts, betray their spouses, and abandon friends and lose their jobs.

13. The lobes of the cerebral cortex

14. The Lobes of the Cerebral Cortex Questions
What are the functions of the Occipital Lobe? What does damage to this area result in?
What are the functions of the Temporal Lobe? What emotions does this area regulate?
What are the functions of The Parietal Lobe?
What are the functions of The Frontal Lobes?
What has the frontal lobe also been called?
What does the ‘prefrontal cortex’ do? How do we know this?
How does damage to the prefrontal cortex influence a persons personality?

15. The Structure and function of the brain
Parietal Lobe
receives sensory information
from all over the body
Frontal Lobe
‘Executive Control center”
Integrates information from other
Parts of the brain
Involved in problem solving
And personality
Corpus Callosum
Relay between two hemispheres
Hippocampus-
Memory
Temporal Lobe
Language comprehension & Production, hearing, and also play a role in emotional responses and face recognition
Occipital Lobe
Concerned with Vision
Cerebellum
Balance
Medulla
Breathing, heart rate
Pituitary gland
Hormones, homeostasis (master gland)