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level: Sperry (B)

Questions and Answers List

level questions: Sperry (B)

QuestionAnswer
What are the main functions of the left and right hemisphere of the brain?- The lefts role is language, reasoning and logical thought - The right hemispheres function is creativity, imagination and spatial awareness
Background- Vogal and Bogen - Performed the split of the corpus callosum on people with epilepsy - Did not cure epilepsy - Sperry wanted to find out what the patients could and could not do
What hemispheres of the brain control each hand?- The right hemisphere controls of the left hand, while the right hemisphere controls the right hand
What was the aim of Sperry's research?- To show the independent streams of conscious awareness possessed by each hemisphere and to show how each hemisphere has its own memories
What was the research method used in research by Sperry?- A quasi experiment - Could be seen as case studies, extensive tests on few ppts
Strengths and weaknesses of case studies- Strengths: Allow in depth background information, carried out for rare cases where large samples are not available - Weaknesses: Not necessarily generalisable, not always scientific
Materials- Visual stimuli, computer, nude picture, geometric shapes...
What was the IV in research by Sperry?- Having a split brain or not - Control group not needed as the results of the tasks for people without split corpus callosums were already known
What was the DV in research by Sperry?- The participant’s ability to perform a variety of visual and tactile tests
What was the sample Sperry used?-11 patients, severed Corpus Colosseum for treatment of epilepsy - There operations took place at a range of times from the earliest being 5 and a half years ago
What were the key tests conducted?- Visual test - Tactile test
What was the visual test used?- Ppt (with one covered eye) looked at centre of a screen - Visual stimulus appeared on the screen, 1/10 of a second, to fast to get the eyes in the wrong visual field - Everything projected to the left of the screen is passed via the left visual field (LVF) to the right hemisphere and vice versa
What was the tactile test used?- Obejcts placed in ppts left or right hand, could not see them - Information about the objects placed in the left hand is processed by the right hemisphere and vice versa
What were the key findings from the visual test?- Info from RVF could be described in speech - If the same info was presented to the LVF the participant said they did not see anything - But could point to obejct with left hand - $ sign to the LVF and ? to the RVF, the participant could draw the $ sign with his left hand but reported that he had seen a ?
What were the results for the tactile tests?- Object in right hand described in speech or writing -Object in left hand, seemed unaware they were holding anything - 2 objects placed in both hands, hidden in a pile of objects, both hands selected their own object
2 controls and why they are used- Time images appeared on the screen - Same images, some images could trigger the other side of the brain - Same tasks
What are the main conclusions from Sperry's research?- People with split brains have 2 separate visual processors - They have lack of cross-integration - They seem to have two independent streams of consciousness, each with its own memories
Evaluate the research method used by Sperry- Highly controlled experimental design - Quasi exp. , drugs may have affected results
Strengths and weaknesses of the research method- Strengths: Ethical, could investigate variables that aren’t normally investigated - Weaknesses: No control groups, small sample, couldn’t compare to a normal human brain, less control of extraneous variables
Evaluate the data collected by Sperry- Qualitative data, descriptions of pts actions, rich, detailed but subjective - Quantitative data
Strengths and weaknesses of the data collected- Strengths: both types of data, analyse easily, compare, could see experiences of the participants - Weaknesses: not a lot of qualitative data, could have guessed answers
What are the possible ethical considerations in this research?- Mostly ethical - Being shown the nude picture, could be uncomfortable - Ethical surgical issues, there are many ways split brain patients could be emotionally affected
Assess to what extent Sperry's research can be seen as valid- Small sample, can abnormal behaviour shown is generalisable to a normal brain? - Differences in their brain may be caused by epilepsy or the medication they take
Assess to what extent Sperry's research can be seen as ecologically valid- In real life spli brain person would use both sides of their hemispheres - High eco valid, served corpus callosum part of their real life - Low Ecol valid, artificially separate the visual and tactile info, ARTIFICIAL SETTING
Evaluate the sample used in Sperry's research- Small sample - Have to question whether abnormal behaviour can be generalised to a normal brain
Discuss the extent to which research by Sperry can be seen as ethnocentric- Brain lateralisation is determinded by the physiognomy of our brain - Not ethnocentric as it is species specific behaviour - However our environment and culture affect brain development
To what extent does research by Sperry support psychology as a science?- Controlled lab experiment which fulfilled scientific criteria of control, evidence and replication - It is falsifiable
To what extent does research by Sperry be considered useful?- Sperry's work allowed a greater understanding of the physiognomy of the brain - It revealed the importance of the Corpus Callosum
Discuss relation by Sperry in relation to the free will vs determinism debate- Biological determinism, the functions of the brain are fixed
How does reserach by Sperry link to the biological area?- Investigates regions of the brain + lateralisation of brain function
How does research by Sperry link to the key theme?- Regions of the brain - Importance of the Corpus Callosum as a communication pathway between the hemispheres - Outline the functions of the left and right hemispheres