localisation of function in the brain AO3

Question 1

explain how evidence from neurosurgery is a strength

Answer 1

• damage to areas of the brain has been linked to mental disorders
• Darin Dougherty et al. (2002) reported in 44 people with OCD who had undergone a cingulotomy (isolating a region implicated in OCD). At a post-surgical follow up after 32 weeks about 30# had met the criteria for successful response to the surgery and 14% for partial response.
• the success of these procedures suggests that behaviours associated with serious mental disorders may be localised

Question 2

explain how evidence from brain scans is a strength for localisation of brain function
- is there a counter ?

Answer 2

• supports idea that many everyday brain functions are localised
• petersen et al. (1988) used brain scans to demonstrate how Wernickes area was active during a listening task and Broca’s area was active during a reading task.
• also, a review of long-term memory studies by Buckner and Petersen (1996) revealed that semantic and episodic memories reside in different parts of the prefrontal cortex.
• this confirms localised areas for everyday behaviours
• objective methods for measuring brain activity have provided sound scientific evidence that many brain functions are localised

COUNTER
- Karl Lashley (1950) removed areas of the cortex (between 10% and 50%) in rats that were learning the route through a maze. No area was proven to be more important than another in terms of the rats ability to learn the route. The process of learning seemed to require every part of the cortex rather than confined to a certain area. Suggests functions are distributed in a more holistic way.

Question 3

explain why language localisation being questioned is a limitation?

Answer 3

• language may not be localised just to Broca’s and Wernicke’s area
• a recent review by Dick and Tremblay (2016) found that only 2% of modern researchers think that language in the brain is completely controlled by Broca’s and Wernickes area.
• Advances in brain imaging techniques like FMRI mean that neural processes in the brain can be studied with more clarity.
• it seems that language function is distributed more holistically than first thought. Language streams have been identified across the cortex including the right hemisphere as well as subcortical regions such as the thalamus.
• suggests it may be organised more holistically?

Question 4

is the case of Phineas Gage a strength or weakness?

Answer 4

strength because it is a unique case of neurological damage that supports the localisation theory