Localisation of brain function

Question 1

Localisation of brain function

Answer 1

The theory that specific areas of the brain are associated with particular physical and psychological functions

Question 2

What hemisphere are language areas on?

Answer 2

The left hand side

Question 3

Broca’s area(hemisphere)

Answer 3

This is responsible for speech production

Question 4

Wernicke’s area(hemisphere)

Answer 4

This plays an important role in understanding other people’s speech and for language comprehension

Question 5

Aphasia

Answer 5

Inability/impaired ability to understand or produce speech as a result of damage to either the Broca or Wernicke area

Question 6

Hemispheric lateralisation

Answer 6

The dominance of one brain hemisphere for particular physical and psychological functions

Question 7

Three concentric layers of the human brain

Answer 7

1. Central core
2. Limbic system
3. The cerebrum

Question 8

Central core role

Answer 8

This regulates our most primitive involuntary behaviours: such as breathing, sleeping or sneezing.
It is also known as the brain stem. It includes structures such as the hypothalamus - in the mid brain.
It regulates eating and drinking as well as regulating the endocrine system in order to maintain homeostasis.

Question 9

Limbic system role

Answer 9

This controls our emotions.
Around the central core of the brain, interconnected with the hypothalamus: it contains structures with key roles in memory as the hippocampus.

Question 10

Cerebrum role

Answer 10

This regulates our higher intellectual processes.
It has an outermost layer known as the cerebral cortex: appears grey because of the location of cell bodies.
Each of our sensory systems sends messages to and from this cerebral cortex.
The cerebrum is made up of these left and right hemispheres which
are connected by a bundle of fibres called the corpus callosum: not having a corpus callosum would result in no coordination.
The corpus callosum enables messages that enter the right hemisphere to be conveyed to the left hemisphere and vice versa

Question 11

Each hemisphere is divided into four lobes:

Answer 11

The frontal lobe
The parietal lobe
The temporal lobe
The occipital lobe

Question 12

Frontal lobe function

Answer 12

The location for awareness of what we are doing within our environment(our consciousness).
An individual’s personality

Question 13

Temporal lobe function

Answer 13

Location for the auditory ability and memory acquisition

Question 14

Parietal lobe function

Answer 14

Location for sensory and motor movements

Question 15

Occipital Lobe Function

Answer 15

Location for vision

Question 16

Somatosensory cortex function

Answer 16

Responds to temperature changes, touch, pain and our sensory of body movement.

Question 17

Motor cortex function

Answer 17

Responsible for controlling voluntary movements. Damage to this area results in impaired movements.

Question 18

Visual cortex function

Answer 18

Primary function is vision

Question 19

Auditory cortex function

Answer 19

Responsible for analysis of speech-based information.

Question 20

Where in the brain is procedural memory located?

Answer 20

Cerebellum

Question 21

Brain scan evidence for the localisation of brain function

Answer 21

Peterson et al(1998) 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 these brain areas have different functions.
Tulving et al(1994)- Episodic memory on the right hand side of the hippocampus, semantic memory on the left side.

Question 22

Neurosurgical evidence for localisation of brain function

Answer 22

This is by far the most extreme treatment as it involves the destruction of healthy brain tissue:

Lobotomy(Freeman)- removal of the brain tissue
Leukotomy: cutting the connections to a particular brain part.
Controversially, neurosurgery is still used for treatment-resistant severe depressives and extreme OCD cases.
Dougherty et al(2002)- lesioning of the cingulate gyrus(involved in emotional control and behavioural regulation): 44 patients with OCD, a third of patients had lessened OCD symptoms after surgery.
The success of these procedures suggests symptoms and behaviours associated with serious mental disorders are localised.

Question 23

Case study evidence for localisation of brain function - Gage’s change in personality

Answer 23

Results: He survived after an explosive went to his eye, and after months of recovery wanted to regain his job. His personality changed from someone who was kind and reserved to someone boisterous, rude and grossly blasphemous(damage to frontal lobe). Although this accident was horrific, it taught us a great deal about the complexity of psychological processes occurring in the human brain.

Question 24

Negative evaluation for localisation of brain function - Higher cognitive functions are not localised

Answer 24

The work of Karl Lashley(1950) suggests the basic motor and sensory functions were localised, but higher mental functions were not.
Rats had 10-50% of their cortex removed. No area was shown to be more important than any other rea of the rats’ ability to learn a maze.
The process of learning appeared to require every part of the cortex, rather than being confined to a particular area.
This seems to suggest learning is too complex to be localised and requires the involvement of the whole brain.

Question 25

Negative evaluations of localisation of brain function - how is neuroplasticity a criticism of localisation function of the brain

Answer 25

Cortical remapping - the brain is able to reorganise itself in an attempt to recover the lost function The law of equipotentiality - surviving brain circuits ‘chip in’ so the neurological function can be achieved. Equipotentiality - notion all areas of the brain are equally able to perform a task e.g. memory functioning was thought to be distributed diffusely throughout the cortex rather than related to defined circuits and pathways.

Question 26

Damage to left hemisphere…

Answer 26

Affects right side of body

Question 27

Localisation of function too reductionist

Answer 27

Cognitive processes and behaviours such as language are too complex to be reduced to one specific brain region, and a more thorough understanding of the brain is required to understand these complex cognitive processes.