localisation of function in the brain Flashcards
what is localisation of function in the brain and when did it come about?
theory that specific areas of brain are associated with particular physical and psychological functions
theory came in 19th century (used to be thought brain was holistic)— discovered by Broca and Wernicke
what are the 3 concentric laters of the human brain?
- the central core
- the limbic system
- the cerebrum
the central core?
- regulates most primative and involuntary behaviours e.g. breathing, sleeping etc
- includes brain stem and regulates endocrine system and regulates behaviours like eating and drinkin
what is the limbic system?
- it controls our emotions
- around the central core
- contains hippocampus (responsible for memory)
what are the 4 lobes in the cerebrum?
parietal
occipital
frontal
temporal
parietal and frontal lobe function?
parietal- processes sensations from skin and muscles (sensory info)
- aids learning in complex, precise movements e.g. writing
frontal- key for planning, decision-making, thought and reasoning, has broca area
occipital and temporal lobe function?
occipital- responsible for vision
temporal- responsible for hearing, language (has wernicke area), memory (hippocampus)
broca area in brain function?
key for speech production
wernicke area in brain function?
responsible for language comprehension, receives info from auditory cortex and functions to assign words to meanings
motor area and somato sensory area functions in brain?
motor area- for voluntary moment
somato sensory area- processes sensory info from sense organs
what is wernicke aphasia and broca aphasia?
wernicke aphasia= diagnosis for people who have difficulty understanding language
broca aphasia= diagnosis for ppl with difficulty producing speech
phineas gage case study what happened?
- was working on railroad and iron rod went through his frontal lobe —> he survived and after recovery joined his job again
- before he was well-balanced mind, efficient, capable, kind then after he was boisterous, rude etc and “no longer Gage” according to his friends
eval points (part1)
case study evidence of phineas gage- BUT case studies = ungeneralisable
eval point 2
brain scan evidence e.g. Peterson et al who showed wernickes area was active during listening task and brocas area active during reading task
—> suggests these areas have different functions
eval point 3
neurosurgical evidence
- involves destruction of healthy brain tissue—> lobotomy (removal of brain tissue- unethical?) and leucotomy (cutting connections to particular part of brain)
—> is used for treatment of severe depressives or OCD and has high success= suggests symptoms of mental disorders are localised
eval point 4
higher cognitive functions = not localised
- lashley suggests basic motor and sensory functions are localised BUT higher mental functions aren’t and are holistic —> he removed areas of cortex in rats that were learning a maze and no area was proven more important than another and learning required every part of the cortex —> suggests learning is too complex to be localised and needs the whole brain —> BUT he used animals not humans
eval point 5
- plasticity (lashley law of equipotentiality)
—> after brain has been damaged and particular function lost rest of brain can reorganise itself and recover lost function —> surviving brain circuits ‘chip in’ —> lots of evidence in stroke victims
eval point 6
- techniques (PET, MRI, fMRI) used for supporting evidence of localisation of function= objective and clinical= can be replicated and consistently checked
