Localisation of function in the brain

Question 1

Define localisation of function in the brain.

Answer 1

The theory that different area of the brain are responsible for different behaviours, processes or activites.

Question 2

What is the opposing argument to the localisation of function theory?

Answer 2

The hollistic theory suggests that all parts of the brain are involved in the processing of thought and action.

Question 3

How many hemispheres are in the brain?

Answer 3

Two
The right and left.

Question 4

What are the four lobes of the brain?

Answer 4

Frontal
Pariteal
Temporal
Occipitial

Question 5

Where is the motor area found?

Answer 5

The back of the frontal lobe.

Question 6

What does the motor area of the brain control?

Answer 6

Voluntary movement on the opposite side of the body.

Question 7

What may happen if there is damage to the motor area of the brain?

Answer 7

A loss of control over fine movements.

Question 8

Where is the somatosensory area found?

Answer 8

The front of the parietal lobes.

Question 9

What does the somatosensory area control?

Answer 9

Sensory information from the skin.

Question 10

How does the somatosensory area work?

Answer 10

The amount of somatosensory area devoted to a particular body part denotes its sensitivity. For example, receptors for our face and hands occupy over half of the somatosensory area.

Question 11

Where is the visual area found?

Answer 11

In the occipital lobe.

Question 12

What does the visual area of the brain control? How does this work?

Answer 12

Vision. The left visual area connects to the right eye and the right visual area to the left eye.

Question 13

Where is the auditory area found?

Answer 13

In the temporal lobes.

Question 14

What does the auditory area of the brain control?

Answer 14

Speech based information.

Question 15

What may happen if there is damage to the auditory area of the brain?

Answer 15

Damage may produce partial hearing loss; the more extensive the damage, the more extensive the loss. In addition, damage to a specific area of the temporal lobe may affect the ability to comprehend language.

Question 16

Which side of the brain is language restricted to?

Answer 16

The left side in most people.

Question 17

What is Broca’s area. Where is it?

Answer 17

An area in the left frontal lobe which is responsible for speech production.

Question 18

What may happen if there is damage to Broca’s area?

Answer 18

This could cause Broca’s aphasia which is characterised by slow and laborious speech which lacks in fluency.

Question 19

Where is it found and what is Wernicke’s area?

Answer 19

Wernicke’s area is found in the left temporal lobe and is responsible for language comphrension.

Question 20

What can happen if Wernicke’s area is damaged?

Answer 20

This can result in Wernicke’s aphasia. This can lead patients to produce nonsence words.

Question 21

How does brain scan evidence support the localisation of function in the brain?

Answer 21

Peterson et al used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task, suggesting that these areas of the brain have different functions. Similarly, Tulving et al revealed that semantic and episodic memories reside in different parts of the prefrontal cortex. There now exists a number of highly sophisticated and objective methods for measuring activity in the brain which provide sound scientific evidence of localisation of brain function.

Question 22

How is neurosurgical evidence a strength of localisation of function the brain?

Answer 22

The practice of surgically removing or destroying areas of the brain to control aspects of behaviour developed in the 1950s. Early attempts such as Freeman who developed the lobotomy, were brutal and imprecise and typically involved severing connections in the frontal lobe in order to control aggressive behaviour. Neurosurgery is still used together to treat extreme cases of OCD and depression. For example, Doherty reported on 44 people with OCD who had undergone cingulotomy (a neurosurgical procedure that involves the lesioning of the cingulate gyrus. A post-surgical follow-up after 32 weeks found that 1/3 had met the criteria for successful response to the surgery and 14 percent for partial response. The success of procedures like this suggests that symptoms and behaviours associated with serious mental disorders are localised.

Question 23

How does the case study of Phineas Gage support the localisation of function in the brain?

Answer 23

Whilst working on the railroad in 1848, 25-year old Phineas Gage was preparing to blast a section of rock with explosives to create a new railway line. Gage dropped his tamping iron onto the rock causing the explosive to ignite and hurling the pole through his left cheek. It passed behind his left eye, and excited his skull from the top of his head taking a portion of his brain with it (most of his frontal lobe). Gage survived but the damage to his brain had left a mark on his personality-he had turned from someone who was calm and reserved to someone who was quick-tempered and rude. This is seen as a landmark case in science as the change in his temperament following the accident suggests that the frontal lobe may be responsible for regulating mood.

Question 24

How is plasticity a weakness of the localisation of function in the brain?

Answer 24

When the brain has become damaged through illness or accident, and a particular function has been lost, the rest of the brain appears able to recognise itself in an attempt to recover the lost function. There are several documented cases of stroke victims being able to recover those abilities that were seemingly lost as a result of illness.