Localisation of function in the brain Flashcards
localisation of function
the theory that different areas of the brain are responsible for different behaviours, processes, or activates
Holistic theory
all parts of the brain were involved in the processing of thought and action
Localisation
different parts of the brain perform different tasks and are involved with different parts of the body
└if a certain area of the brain becomes damages, the function associated with that part of the brain will be damaged
Localisation
people
└19th century
└Broca and Wernicke
Hemispheres of the brain
└brain divided into two symmetrical halves
└left and right hemispheres
└activity on left hand side of the body is controlled by the right hemisphere
└activity on right hand side of the body is controlled by the left hemisphere
What hemispheres control activity
└activity on left hand side of the body is controlled by the right hemisphere
└activity on right hand side of the body is controlled by the left hemisphere
Cerebral cortex
└outer layer of both hemispheres
└separates us from other animals as is much more developed
└appears grey due to location of cells (grey matter)
Areas in brain
list
Motor area
Somatosensory area
Visual area/cortex
Auditory area
Motor area
location and function
└back of the frontal lobe in both hemispheres
└controls movement in the opposite side of the body
└damage to this area= loss of control over fine movements
Somatosensory area
location and function
└front of the parietal lobes
└separated from motor area by the central sulcus
└processes sensory information such as touch
Visual area/cortex
location and function
└occipital lobe at back of brain
└receives and processes visual information
└each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex
└damage to left hemisphere can produce blindness in part of right visual field in both eyes
Auditory area
location and function
└in the temporal lobe
└analysis of speech based information
└damage may produce partial hearing loss
└damage to Wernicke’s area may affect ability to comprehend language
The language area of the brain
parts
Broca’s area
Wernicke’s area
Broca’s area
location and function
what happens if damaged
└area of the frontal lobe of the brain in the left hemisphere
└responsible for speech production
└damage= Broca’s aphasia (slow laborious speech that lacks fluency)
Wernicke’s area
location and function
what happens if damaged
└area of the temporal lobe in the left hemisphere
└responsible for language comprehension
└damage= Wernicke’s aphasia (often produce nonsense words (neologisms) as part of the content of their speech)
The language area of the brain
parts
Broca’s area
Wernicke’s area
Broca’s area
location and function
what happens if damaged
└area of the frontal lobe of the brain in the left hemisphere
└responsible for speech production
└damage= Broca’s aphasia (slow laborious speech that lacks fluency)
Wernicke’s area
location and function
what happens if damaged
└area of the temporal lobe in the left hemisphere
└responsible for language comprehension
└damage= Wernicke’s aphasia (often produce nonsense words (neologisms) as part of the content of their speech)
Localisation of function in the brain
strengths
summary
Brain scan evidence of localisation - Petersen et al (1988) , Tulving et al (1994)
Neurosurgical evidence : Walter Freeman ,Dougherty et al (2002)
Case study evidence - Phinease Gage case study(1848)
Localisation of function in the brain
strengths
Brain scan evidence of localisation
└Petersen 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
└suggesting some areas of the brain have different functions
└Tulving et al (1994)
└study of long term memory
└semantic and episodic memories are located in different parts of the prefrontal cortex
└scientific evidence
Localisation of function in the brain
strengths
Neurosurgical evidence
└the practice of surgically removing or destroying areas of the brain to control aspects of behaviour developed in the 1950s
└Walter Freeman developed lobotomy
└brutally sever connections in frontal lobe to try and control aggressive behaviour
└neurosurgery still used in extreme cases today
└OCD, depression
└Dougherty et al (2002)
└reported on 44 OCD patients that had a clingulotomy (lesions the cingulate gyrus)
└post-surgical follow up after 32 week= 1/3 successful response, 14% partial response
└the success of procedures like this suggests symptoms and behaviours associated with serious mental disorders are localised
Localisation of function in the brain
strengths
Case study evidence
└Phinease Gage case study(1848)
└explosion on railway line building site caused a pole to go through his skill, mainly removed left frontal lobe
└personality: calm and reserved → rude and quick tempered
└suggests frontal lobe responsible for regulating mood
