(brain) localisation of brain functions AO3

Question 1

(+) evidence from neurosurgery

Answer 1

P: strength of localisation theory is damage to areas of the brain have been linked to mental disorders

E: dougherty et al. 2002 - reported 44 people w/ OCD who’d undergone a cingulotomy & post-surgical follow up after 32 weeks said ~32% met criteria for successful response & ~14% for partial response

E/L: success of procedures suggests behaviours associated w/ mental disorders can be localised

Question 2

cingulotomy

Answer 2

involves isolation region of brain called cingulate gyrus which has been implicated in OCD

Question 3

(+) evidence from brain scans

Answer 3

P: evidence from brain scans which support idea many everyday brain functions are localised

E:
- Petersen et al. (1988) used brain scans to demonstrate how Wernicke’s area was active during listening task & Broca’s area active during reading task
- review of LTM studies by buckner & petersen (1996) revealed semantic & episodic memories reside in diff parts of the prefrontal cortex
= studies confirm localised areas of brain for everyday functions

E/L: objective methods for measuring brain activity have provided scientific evidence many brain functions are localised

Question 4

(-) counterpoint to evidence from brain scans

Answer 4

P: challenge to localisation theory from lashley (1950)

E: he removed areas of cortex (between 10-50%) in rats learning route of a maze. no area proven to be more important than any other in their ability to learn route. process of learning required every part of cortex & not confined

E/L: suggests higher cognitive processes, eg. learning, are not localised but distributed in more holistic way

Question 5

(-) language localisation questioned

Answer 5

P: language may not be localised just to broca’s/wernicke’s areas

E: review by dick & tremblay (2016) - 2% of modern researchers believe language in brain completely controlled by these. advance in brain imaging techniques (eg. fMRI) mean neural processes can be studied & seems language function distributed more holistically. language streams been identified across cortex incl. right hemisphere & subcortical regions (eg. thalamus)

E/L: suggests language may be organised more holistically contradicting localisation theory

Question 6

(+/-) case study evidence

Answer 6

P: unique cases of neurological damage support localisation theory

E: eg. phineas gage - metre length pole through left cheek, behind eye & out of top of head which took most of frontal lobe with it. he survived but personality changed - was calm/reserved to quick-tempered & rude

E/L: suggests frontal lobe may be responsible for regulating mood

COUNTERPOINT E/L: problems with case studies as difficult to make meaningful generalisations from findings of individuals as depends on subjective interp. of researcher