Biospychology- localisation of function

Question 1

What is localisation of function?

Answer 1

Functions, such as movement speech and memory are performed in distinct regions of the brain.

Question 2

What is a contradictory theory to the localisation of function theory?

Answer 2

Holistic theory - belief that all parts of the brain are involved in the processing of thought and action.

Question 3

What is hemispheric lateralisation of function?

Answer 3

The brain is divided into two symmetrical halves known as left & right hemispheres. Some of our physical and psychological functions are controlled or dominated by a particular hemisphere - this is called lateralisation.

Question 4

What is the cerebral cortex?

Answer 4

The outer layer of both hemispheres is the cerebral cortex (grey matter). The cortex is about 3mm thick. The context is what separates humans from other animals as it is much more developed.

Question 5

What is the sulci and gyri?

Answer 5

Gyri -ridges on the surface of the brain.
Sulci - grooves in the cerebral cortex.

Question 6

What are the 4 lobes of the brain?

Answer 6

Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe.

Question 7

What is the limbic system?

Answer 7

It is also known as the mammalian brain or midbrain. This part of the brain is unique to mammals.
According to Maclean (1990), the limbic system is the centre of emotion and learning.

Question 8

What is the early research of localisation of function?

Answer 8

• Neuro-surgeons Broca and Wernicke were the first to provide scientific evidence for the idea of localisation of function.
• It follows that if a certain area of the brains becomes damage through illness or injury, the function associated with that area will also be affected.

Question 9

What did Broca identify in 1865?

Answer 9

A smalls area in the left posterior frontal lobe for speech production. Damage to Broca’s area causes Broca’s aphasia which is characterised by speech that is slow, laborious and lacking fluency.

Question 10

What did Karl Wernicke identify in (1873)?

Answer 10

Studied patients who had no problems with language production but severe difficulty with language comprehension.

He identified an area in the left posterior temporal lobe as being responsible.

This is known as Wernicke’s area. Patients with Wernicke’s aphasia often produce nonsense words.

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Question 11

Describe the procedure and findings of Broca?

Answer 11

Procedure - studied a patient called tan and eight other post-mortems who had speech production issues and lesions in the their left frontal hemisphere.
Findings - this led Broca to identify the existence of a language centre for speech production in the posterior portion of the frontal lobe of the left hemisphere.

Question 12

Describe the study of Wernicke 1873?

Answer 12

Procedure: studied a patient who suffered a stroke and could not understand language. He studied his brain post-mortem.

Findings - this led Wernicke to identify that the area of the brain involved in understanding language was in the posterior portion of the left temporal lobe.

Question 13

What is the role of the motor area in the brain?

Answer 13

Located in the frontal lobe and is responsible for voluntary movements by sending signal to the muscles in the body.

Question 14

What is the role of the somatosensory area?

Answer 14

Located in the parietal lobe and incoming sensory information from the skin to produce sensations related to pressure, pain, temperature, etc. Different parts of the somatosensory area receive messages from different locations of the body.

Question 15

What is the role of the visual area?

Answer 15

At the back of the brain, in the occipital lobe is the visual area, which receives and processes visual information. The visual area contains different parts that process different types of information including colour, shape or movement.

Question 16

What is the role of the auditory area?

Question 17

What is the role of the auditory area?

Answer 17

The auditory area is located in the temporal lobe and is responsible for analysing and processing acoustic information. The auditory area contains different parts and the primary auditory area is involved in process six simple features of sound including loudness tempo and pitch.

Question 18

What is the role of Broca’s area?

Answer 18

Located in the left frontal lobe responsible for speech production.

Question 19

What is the role of Wernicke’s area?

Answer 19

Located in the left temporary lobe responsible for language comprehension.

Question 20

What is one strength of the theory of localisation of function?

Answer 20

Evidence from brain scans.

Question 21

What are two weaknesses of the theory of localisation of function?

Answer 21

Equipotentiality
Individual differences.

Question 22

Explain the strength of evidence from brain scans supporting the idea of localisation of function. (PEEL)

Answer 22

P: a strength of the theory of localisation of function is that there is a wealth of evidence from brain scans providing support that neurological functions are localised.
E: Tulving (1994) revealed that somatic and episodic memories reside in different parts of the prefrontal cortex with semantic memories in the left hemisphere and episodic in the right.
E: both of these studies show that the different areas of the brain are active during different cognitive functions demonstrating localisation of function.
L: this strengthens the validity of the theory as it provides empirical evidence to support that idea that different brain regions carry out different functions.

Question 23

What is equipotentiality as a limitation of localisation of function?(PEEL).

Answer 23

P: a limitation of the theory of localisation of function is that it has been criticised by researchers who argue that the brain works more holistically.
E: Lashley (1959) proposed an alternative theory known as the principle of equipotentiality which suggests that basic motor and sensory functions are localised but the higher mental functions are not. This was based on a study where he removed between 10 to 50% of the cortex of rats and found no area to be more important than the other.
E: lashley argues that localisation insbiologically productionist as it tries to reduce very complex human behaviours and cognitive processes to one specific brain region.

Question 24

What is individual differences as a limitation of the theory of localisation of function?(PEEL)

Answer 24

P: limitation of the theory of localisation of function is its failure to consider individual differences.
E: Harasty et al (1997) found that women have proportionately larger Broca’s and Wernicke’s areas than men which might explain women’s greater ease with language. This introduces a beta bias as a theory overlooks gender differences.
E: additionally individual differences extend beyond gender to include age related changes in brain function and plasticity. These differences are crucial for developing effective treatments for neurological conditions ignoring them can be a result in less effective interventions.
L: generalising research on localisation of function to both genders without considering these differences is problematic.