Biopsychology

Question 1

Findings from split brain research

Answer 1

• when a picture of an object was shown to a patient right visual field = patient could easily describe what was seen
  However the same object was shown to the left visual field= patient could not describe what was seen= typically reported nothing was there
  This is because language is processed in the left hemisphere
  This means the patient ability to describe objects in the left visual field was due to lack of language centres in right hemisphere

2. Matching words or faces = The right hemisphere appeared to dominate the ability to match a list
   of faces to a given stimulus. This is due to the right hemisphere contairing the brain’s visuo-spatial centres, thus allowing for the visual identification and processing of the faces.
3. Words presented simultaneously = If two words were presented at the same time, each to one of
   the visual fields, the patient would say the word presented to the right visual field (processed by the left hemisphere with language centres) and write down the word presented to the left visual field (processed by the right hemisphere and containing visuo-spatial centres).
4. Recognizing objects placed into the hands = If an object was placed into the patient’s right hand,
   they would be unable to identify that it is there, because the information would be processed by the left hemisphere which only has language centres, and no visuo-spatial centres. Therefore, if an object was placed into the patient’s left hand, they would be able to identify the object and choose a similar one from a hidden bag, due to the action of the visuo-spatial centres.

Question 2

Split brain research into hemispheric lateralisation

Answer 2

1. Demonstrated lateralized brain functions
   E- sprerry pioneering work into the split brain research has produce an impressive body of research findings
   Main conclusion that left hem- more geared towards analytical and verbal task whilst the right is more adapt at performing spatial task and music
   E- therefore it suggest that the left hemisphere is the analyzer whilst the right hemisphere is the synthesizer
   L — key contribution to outlet understanding of brain processes
2. Strength of methodology
   - experiment made use of highly specialized and standardized procedures
   - sperry method involved visual info being presented to 1 hemispheric field as a time= typically p’s would be ask to stare at a fixation point whilst one eye is blindfolded
   Image projected would be flashed up for 1/10 of a second= meaning split brain p won’t have time to move their eyes across the image-And then would spread info across both sides of visual field
   -this ensure they only 1 hemispheres was receiving info at a time
   - this developed a well controlled procedure

3.Issues with generalization
- only 11 who took part in all variation of the basic procedure = all whom had history of epileptic seizures
- argued this may have caused unique changes in brain= influence finding= epileptic p’a have been taking anti epilepsy medication for an extended period of time
- therefore the findings not representative of the wider population

4.Research suggested that language may not be restricted to the left hem
- Pufetti et al - suggested there’s been cases of split brain p’s who are left handed but produce and comprehend speech in the right hemisphere = this oppose the prediction made by lateralization theory
- therefore= important not to jump to conclusions that left hem is responsible for language whilst right responsible for visual spatial task

Question 3

Circadian rhythm

Answer 3

• has practical application to drug treatment
  Research into CR has revealed there’s certain peak time during day or night when drugs likely to be most effective
  Led to the development of guidelines to do with the timing of the drug dosing for a whole range of medication

Use of case studies= small sample
May not be able to generalized to wider population as there can be individual differences in duration and stages of CR
Siffre noted as he grew older at the age of 60 his internal clock ticked much more slowly than when he was a young man= uncontrolled variable in his investigation
- illustrated even when same person is involved= there factors that vary which means prevent general conclusion being drawn

Poor control in studies
- they were deprived from natural light but still had access to artificial ligh
- suffer turned on a lamp every time he wake up and remained on till he went to bed
- was assumed by him and other research that artificial bad no effect on the free running biological rhythm
However studies shown artificial ligh can create shift in circadian rhythm by up to 6 hours
- shows siffre have entrained his own CR through using light to sleep and wake up
Means conclusion made about his free running circadian rhythm Amy not be entirely accurate