biopsychology- localisation of function Flashcards
What does localisation of function mean?
functions such as movement, speech and memory are performed in distinct regions of the brain (localised).
What does lateralisation of function mean?
-brain divided into two (nearly) symmetrical halves known as left and right hemispheres
-some of our physical and psychological dominated by a particular hemisphere- this is called lateralisation.
how does lateralisation of function contrast to a holistic view?
contrasting view to localisation which is the belief that all parts of the brain are involved in the processing of thought and action
What is the outer layer of the brain called?
the cerebral cortex- about 3mm thick, folded for bigger surface area, separates humans from other animals as much more developed.
gyri
folds in the brain
sulci
gaps in the brain
What are the 4 lobes of the brain called?
parietal lobe, occipital lobe, frontal lobe, temporal lobe
What is the role of the limbic system?
unique to mammals, centre of emotion and learning (not on spec don’t need to learn), known as mammalian brain
What is Broca’s aphasia?
characterised by speech that is slow, laborious, and lacking in fluency.
how is Broca’s aphasia caused?
-damage to Broca’s area (a small area in the left posterior frontal lobe for speech production)
What is Wenicke’s aphasia?
Patients often produce nonsense words.
how is Wernicke’s aphasia caused?
area in left posterior temporal lobe responsible for language comprehension- known as Wernicke’s area
How is the case of Phineas Gage seen as evidence for the localisation of function?
-railway worker, explosion on rail line caused rod to go through left cheek, behind eye and through top of head.
-survived but damage to brain left mark on personality- turned from calm and reserved to quick tempered, rude and ‘no longer Gage’.
areas of the brain
role of the frontal lobe
motor area responsible for voluntary movements, send signals to muscles in body
role of the parietal lobe
somatosensory area receives incoming sensory info from skin to produce sensations related to pressure, pain, temperature, etc
role of occipital lobe
visual area receives and processes visual info. It contains different parts that process different info types including colour, shape, or movement.
role of temporal lobe
auditory area responsible for analysing and processing acoustic info
role of left frontal lobe
Broca’s area found in left frontal lobe and is thought to be involved in language production.
role of left temporal lobe
where Wernicke’s area is found in the left temporal lobe and is thought to be involved in language comprehension.
How is the spatial arrangement of the motor cortex linked to its function?
the regions of the motor area are located in a logical order. For example, the region that controls finger movement is located next to the region that controls the hand, arm and so on.
ao3- holistic argument against the localisation of function- research
P- brain works more holistically
E- Lashley (1950) alt theory principle of equipotentiality suggests basic motor and sensory functions localised but higher mental functions aren’t. removed 10-50% of the cortex of rats and found no area more important than others. intact areas can take over responsibility following a brain injury
E- biologically reductionist as tries to reduce very complex man behaviours and cognitive processes to one specific brain function
L-more thorough understanding of the brain requires to understand complex cognitive processes like language
ao3- beta bias
P- fails to take into account individual differences
E- Harasty (1997) found women have a proportionally larger Broca’s and Wernicke’s area than men may explain why women have greater ease of language
E- suggests a level of beta bias in the theory as differences between men and women are ignored and variations in the pattern of activation and the size of localised areas are not considered.
L- unable to generalise research examining localisation of function, as the different structures may mean different considerations are required considering the different sexes.
Give an example of a case that has supported the localisation of function.
P- case studies on p’s w/ brain damage
E- patient HM, experimental surgery to remove hippocampi to cure epilepsy. after removed no longer able to transfer episodic and semantic memories from STM to LTM but could still complete new procedural tasks such as mirror drawing
E- shows hippocampus has a role in formation of new LTM memories, apart from procedural LTMs which must be formed in another area of the brain.
How has imaging data supported the localisation of function
P- evidence from brain scans that provide support that neurological functions are localised
E- Tulving (1994) revealed semantic and episodic memories reside in different parts of the prefrontal cortex with semantic memories in the left hemisphere and episodic to the right.
E- shows different areas of the brain active during different cognitive function
L- strengthens validity of the theory as it provides empirical evidence to supports the idea that different brain regions carry out different functions
