Localisation of function in the brain evaluation

Question 1

Lashley’s research

Answer 1

Cognitive functions are not distributed in a certain location but rather it is holistic. Lashley removed areas of the cortex in rats who were learning a maze. Found that Process of learning the maze required every part of the cortex rather than it being confined to a localised area. Limitation as it suggests that learning is too complex to conclude that it is localised and rather we have to look holistically.
+c= Animal study, cannot extrapolate

Question 2

Brain scan evidence of localisation

Answer 2

many functions are localised. 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 have different functions. support as it shows that Broca responsible for speech production (reading) while Wernicke responsible for language comprehension.

Further study by Tulving revealed that semantic and episodic memories reside in different parts of the prefrontal cortex. Also many objective methods introduced to show scientific evidence of localisation of brain function. (empirical evidence)

Question 3

Neurosurgical evidence

Answer 3

Freeman developed the lobotomy which involved severing connections in the frontal lobe to control aggressive behaviour. Still used today for severe cases of OCD and depression.
Dougherty et al studied 44 people with OCD who had undergone cingulotomy. After 32 weeks a third had met the criteria for successful response and 14% for partial response.
Support because it has real life application and can help to improve people’s lives by studying symptoms which are localised.

Question 4

Case study of Phineas Gage

Answer 4

A pole went through Gage’s left cheek passing behind his left eye and exiting his skull from the top of his head taking a portion of his brain with it (left frontal lobe). He survived but his personality changed and he went from someone who was calm to someone who was quick tempered. This suggests that the frontal lobe may be responsible for mood regulation. uses idiographic approach of case studies which is helpful as it sheds light on unique cases but not generalisable.

Question 5

There are Individual and gender differences in language areas

Answer 5

Language activities can vary from individual to individual. Bavelier et al found variability in patterns across different individuals when reading. Harasty et al found gender differences for Wernicke’s area and Broca’s. Women tend to have proportionally larger Broca’s and Wernicke’s areas than men. limitation as individual differences mean that lateralisation cannot be universalised and contains gender bias as it assumes that all genders brain function similarly.