Biopsych Year 2 Flashcards
History of the brain
Before 19th century it was believed that all areas of brain were involved in same functions
- holistic theory
Localisation of function
Different parts of brain are involved with certain tasks
If certain areas of the brain are damaged the function associated with this area will also be damaged
Frontal lobe
Motor area
Involved with regulating movement
Broca’s area
Found in frontal lobe in LH
responsible for language comprehension
If damaged people will struggle to produce speech but will understand what is being said to them
Broca’s aphasia
Parietal lobe
Somatosensory cortex - sensory info from skin eg heat
Touch, pain, taste
Occipital lobe
Visual cortex - vision, detection of movement + colour
temporal lobe
auditory area - word understanding, memory, speech, hearing, language
Wernicke’s area
left temporal lobe
understanding of language. If damaged, people will struggle to understand spoken language.
evaluation LOF
strength - supportive research
P: supportive research - case studies eg. Phineas Gage
E: PG had an incident at work where a metal rod went through his brain, it affected his frontal lobe. He became more aggressive and lost his job.
C: supports LOF as his behaviour changed but language + vision stayed in tact. But, case studies are unique so findings not generalised to everyone. Doesn’t tell us about LOF in everyone else.
evaluation LOF strength - scientific
P: research into LOF now scientific as uses brain scans
E: eg. PET scans to study activity of Broca + Wernickes area during a reading + listening task. Brocas - active in reading, Wernickes active in listening.
C: EVs controlled. C+E relationship established eg. Broca’s - active during reading task
evaluation LOF limitation - contradictory evidence
P: contradictory evidence
E: Lashley conducted research by removing different parts of a rat’s brain to see the effect of this on rat’s ability to navigate through maze. He found that no matter what part of brain removed, rat still remembered its way out.
C: supports holistic theory. says it doesn’t matter which part of brain is removed. But, using rats is less scientific as rats brain diff to humans - can’t generalise.
hemispheric lateralisation
idea that the 2 hemispheres of the brain are funtionally different.
eg. left is language and right is creativity.
1968 sperry procedure for split brain research
image/word projected to left or right visual field for 0.25 secs.
info would be processed by opposite hemisphere. in a normal brain, info would be shared by both hemispheres so wouldn’t matter which VF it was presented to. in split brain patient, this is not possible.
Sperry findings
- when image was shown to RVF the patient could easily describe what was seen but couldn’t if image was shown to LVF. because RVF is in LH and responsible for language.
- if 2 words were presented simultaneously on either side of the VF, patient would write the LVF word and say the RVF word. proves LH is responsible for language and RH is for creativity.
evaluation - hemispheric lateralisation strength - supportive research
E: research after sperry (Gazzaniga) had consistent results. they also concluded that LH was responsible for analytic + verbal tasks whilst RH responsible for spatial + music tasks
C: reliable - results consistent across many studies
evaluation - hemispheric lateralisation strength - scientific
P: supportive research eg. Sperry is scientific
E: could use standardised procedures - keeping all aspects of the study the same each time. eg. same images shown to RVF.
C: C+E relationship eg. things shown to RVF could be described but not if shown to LVF. also, study can be replicated and it increases validity.
evaluation - hemispheric lateralisation HOWEVER point
P: sperry’s sample size is small
E: used 11 patients so sample is unrepresentative. can’t generalise findings.
C: results may not tell us much about hemispheric lateralisation. but, this has since been aleviated by other supportive research.
evaluation - hemispheric lateralisation limitation - contradictory evidence
P:contradictory evidence against sperry’s findings
E: Kim Peek was born without a corpus collosum but could read 2 pages ib 10 secs, reading one with left left eye and one with right eye. so he had bilateral language centres.
C: Kim Peek has language centres in both hemispheres but sperry’s research says they’re is only 1 language centre + it’s in left hemisphere.
but, Kim was born like this so his brain may have evolved.
Plasticity
The brains ability to functionally and physically change and adapt as a result of experience and new learning
Functional recovery of the brain after trauma:
- brains ability to redistribute or transfer functions from damaged to undamaged areas
- brain rewires itself by forming new synaptic connections close to damaged area
- secondary pathways that are not normally used are activated
Functional recovery supported by structural changes in the brain:
- Axonal sprouting - growth of new nerve endings which connect with other undamaged cells to form new pathways
- Growth of new blood vessels - get o2 to brain
- Recruitment of similar areas on opposite side of brain to perform similar tasks
plasticity + functional recovery - case of Jodie
Jodie had many seizures that left her left side under paralysis
her right hemisphere got removed
10 days later she was able to move her left side and she walked out of hospital.
LH made new connections
plasticity + functional recovery strength - supportive research
P: supportive research that shows that our brains do have plasticity
E: Maguire et al studied brains of London taxi drivers - found they had more developed hippocampi than other taxi drivers. Hippocampi helps with spatial + navigational skills. They also found that the longer they had been in job, more developed hippocampus.
C: brains do have plasticity as hippocampi are more developed the longer you’ve been a taxi driver. so, plasticity develops into adulthood.
plasticity + functional recovery strength - useful
P: useful eg. development of treatment such as neurorehabilitation
E: brain recovery can be slow so techniques developed to aid this eg. physical + electrical stimulation. treatment used for people who have suffered strokes etc.
C: leads to better quality of life as people can walk + talk again with independence. This means they can socialise + live a normal life.
plasticity + functional recovery limitation - c0ntradictory research
P: contradictory research eg. plasticity can go wrong
E: rewiring of brain can be maladaptive. Prolonged drug use can cause poor cognitive functioning + increased risk of dementia in later life. also, phantom limb can happen if rewiring goes wrong. 60-80% amputees feel continual sensations of missing limb.
C: can be very difficult to treat if not impossible.
what does fMRI stand for?
functional magnetic resonance imaging
how does fMRI work?
detects changes in blood oxygenation + flow due to brain activity via magnetic fields.
as brain becomes more active it consumes more O2. so blood flow directed to active area - HAEMODYNAMIC RESPONSE
produces moving 3D image of brain - can determine which areas of brain are responsible for certain functions.
strength of fMRI
P: safe to use
E: unlike others eg. x ray, patients aren’t at risk of radiation. so if administered correctly it’s nearly risk free + non invasive (don’t ingest anything)
C: images can be produced several times per patient without placing them at any more risk than normal - reliability as scanned multiple times
limitation of fMRI
P: expensive eg. machinery, training of specialists
E: each scanner can cost over £1million and average cost of 1 scan is also expensive
C: studies that require fMRI have small sample sizes. This can lower understanding
EEG =
electroencephalogram
how does EEG work?
uses skull cap. records brain patterns made by neurons providing an account of brain activity directly under where they’ve been placed
doctors can usually detect whether people have unusual brain activity using EEG which may be caused by epilepsy, tumours + sleep disorders - parasomnia
strength of EEG
P: useful in diagnosis of conditions such as epilepsy
E: now understood that epilepsy is caused by random outburst of activity which can be detected by EEGs. they have also helped our understanding of sleep + sleep disorders
C: we can diagnose people so they can get treatment so will have better quality of life eg. they can drive
limitation of EEG
P: provides us with less detailed data
E: doesn’t pinpoint neural activity as it’s difficult to determine where the activity was originated
C: limits understanding as you can’t truly understand what happens in that area of brain
ERP =
event related potential
how does ERP work
electrodes fixed to patient’s scalp to detect neuronal activity in response to stimulus
brain’s electrophysiological response to specific sensory, cognitive or motor event eg type of brain wave triggered by a specific event
this can be isolated through a statistical analysis of EEG data
strength of ERP
addresses limitations of EEG
P: addresses some of the limitations with EEGs
E: data can be more specific about neural processes in the brain. researchers have been able to identify many diff types of ERP and can describe the precise role of these in cognitive functioning.
C: offers more understanding about cognitive function
strength of ERP
cheaper than fMRI
P: ERPs (+EEGs) cheaper than fMRI
E: allows researchers to use larger sample sizes to study neuronal activity
C: more patient’s brains can be studied so more results collected. more things can be detected + treated.
how does post mortem work?
analysing brain after person has died
individuals have usually suffered a rare brain disorder or experienced unusual mental processes that have affected their behaviour in their life
damaged areas examined to correlate structural abnormalities to behaviour changes
comparisons to normal brain to ascertain differences
strength of post mortem
P: older technique so very useful in early understanding of brain
E: eg. Broca + Wernicke both conducted post mortems - they found LOF as they discovered diff areas of the brain were associated with particular functions
C: increased understanding years ago of brain structure + functioning long before development of new technologies to do the same thing
limitation of post mortem
P: ethical concerns around use of post mortems
E: individuals may not be psychologically capable of giving consent eg. HM wouldn’t have been capable of agreeing to undergoing a postmortem due to his memory impairment. However he did undergo a postmortem
C: damages reputation of psychology as people haven’t had any choice of a postmortem.
