Evaluation of Localisation of Function in the Brain

Question 1

What are the 3 strengths?

Answer 1

1. Peterson et al. Study
2. Phineas Gage - case study support
3. conducted in the controlled setting of the laboratory

Question 2

What are the 3 weaknesses?

Answer 2

1. Biologically reductionist
2. Beta Bias
3. MRI scan on Tan’s brain

Question 3

Peterson et al. Study

Answer 3

One strength of the theory of localisation as a theory of brain function is that there is a wealth of supportive evidence:
For example, Peterson 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.
This is a strength because these findings suggest that these particular areas of the brain have different functions, specifically relating to language.
Therefore we can assume there are other localities within the brain responsible for different physical and psychological functions.
As a result, the theory of localisation gains further credibility.

Question 4

Phineas Gage - case study support

Answer 4

Research support from case studies – Phineas Gage was in an accident which caused him to lose part of his frontal lobe which altered his personality – The frontal lobe may play a role in mood regulation therefore localisation theory is correct.

Question 5

Conducted in the controlled setting of the laboratory

Answer 5

A strength of the research conducted in the localisation of function of the brain and hemispheric lateralisation is that it has been conducted in the controlled setting of the laboratory.
For example, research aiming to identify which areas of the brain are responsible for specific behaviours (e.g. language) have used methods such as fMRI scanning, EEG machines and post-mortem examinations.
This is a strength because, such research can be praised for being scientific and objective allowing researchers and psychologists to draw firm conclusions as regards to what parts of the brain are responsible for specific behaviours/activity thus increasing the internal validity of the research.

Question 6

Biologically reductionist

Answer 6

Critics argue that theories of localisation are biologically reductionist in nature and try to reduce very complex human behaviours and cognitive processes to one specific brain region. Such critics suggest that a more thorough understanding of the brain is required to truly understand complex cognitive processes like language.

Question 7

Beta Bias

Answer 7

Finally, some psychologists argue that the idea of localisation fails to take into account individual differences. Herasty (1997) found that women have proportionally larger Broca’s and Wernicke’s areas than men, which can perhaps explain the greater ease of language use amongst women. This, however, suggests a level of beta bias in the theory: the differences between men and woman are ignored, and variations in the pattern of activation and the size of areas observed during various language activities are not considered.

Question 8

MRI scan on Tan’s brain

Answer 8

Although there is evidence from case studies to support the function of the Broca’s area and Wernicke’s area, more recent research has provided contradictory evidence. Dronkers et al. (2007) conducted an MRI scan on Tan’s brain, to try to confirm Broca’s findings. Although there was a lesion found in Broca’s area, they also found evidence to suggest other areas may have contributed to the failure in speech production. These results suggest that the Broca’s area may not be the only region responsible for speech production and the deficits found in patients with Broca’s aphasia could be the result of damage to other neighbouring regions.