Localisation of Functions in the Brain(Biopsychology)

Question 1

Localisation

Answer 1

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

Question 2

Hemispheric lateralisation

Answer 2

The brain’s divided into two hemispheres: the left and right
Each hemisphere (side of the brain) is responsible for specific functions

Hemispheric lateralisation: the dominance of one hemisphere of the brain for particular physical and psychological functions

the right hand side is responsible for the functions of the left hand side of the body and vice versa

Question 3

Language areas of the brain

Answer 3

Broca is responsible for speech production. Wernicke plays an important role in understanding other people’s speech and for language comprehension. Language areas are only found on the left side.

Question 4

The central core

Answer 4

• regulates our most primitive and 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 midbrain
• it regulates eating and drinking as well as regulating the endocrine system in order to maintain homeostasis
• homeostasis is the process by which the body maintains a constant physiological state

Question 5

The limbic system

Answer 5

• this controls our emotions
• around the central core of the brain, interconnected with the hypothalamus, it contains structures such as the hippocampus; key roles in the memory

Question 6

The cerebrum

Answer 6

• 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 (hence “grey matter”)
• each of our sensory systems sends messages to and from this cerebral cortex
• the cerebrum is made up of the left and right hemispheres which are connected by a bundle of fibres called the corpus callosum

Question 7

For Lobes…

Answer 7

…refer to diagram

Question 8

Occipital Lobe

Answer 8

location responsible for vision

Question 9

Parietal Lobe

Answer 9

Location for sensory and motor movements

Question 10

Motor area

Answer 10

responsible for coordination

Question 11

Somatosensory area

Answer 11

responsible for responding to environmental stimuli

Question 12

Frontal Lobe

Answer 12

The location for awareness of what we are doing within our environment (our consciousness)

Question 13

Temporal Lobe

Answer 13

Location for the auditory ability and memory acquisition

Question 14

(Evaluations of localisation) Brain Scan Evidence

Answer 14

• there is a wealth of evidence providing support for the idea that many neurological functions are localised, particularly in relation to language and memory
• Petersen et al. 1988 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
• there now exists a number of highly sophisticated and objective methods for measuring activity in the brain which provide sound scientific evidence for the localisation of brain function
-Tulving: memory is stored in the hippocampus; the left is semantic, the right episodic

Question 15

(Evaluations of localisation) Neurosurgical Evidence

Answer 15

• this is by far the most extreme treatment as it involves the destruction of healthy brain tissue:
-Lobotomy (Freeman): removal of brain tissue
-Leucotomy: cutting the connections to a particular part of the brain
• controversially, neurosurgery is still used today for treatment-resistant severe depressives and extreme cases of OCD
• Dougherty et al 2002…lesioning of the cingulate gyrus
The success of these procedures strongly suggests that symptoms and behaviours associated with serious mental disorders localised

Question 16

(Evaluations of localisation) Case Study Evidence

Answer 16

• Phineas Gage’s head was impaled with an iron pole
• he survived and is personality was found to have changed from being kind and reserved to being rude and boisterous.
• suggested that the part of his brain damaged linked to these parts of his personality

Question 17

(Evaluations of localisation) Higher Cognitive Functions are not localised

Answer 17

• the work of Karl Lashley 1950 suggests that the basic motor and sensory functions were localised, but that higher mental functions were not
• rats had 10-50% of their cortex removed No area was shown to be more important than any other area 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 that learning is too complex to be localised and requires the involvement of the whole brain

-Lashley ‘the law of equipotentiality: a notion developed by Karl Spencer Lashley posing that all areas of the brain are equally able to perform a task, for example, memory functioning was thought to be diffusely distributed throughout the cortex rather than related to defined circuits or pathways

Question 18

Broca’s and Wenicke’s aphasia

Question 19

cortical remapping

Answer 19

(links to plasticity) the brain is able to reorganise itself in an attempt to recover the lost function