Sperry (1968)

Sperry (1968)

1. Method...

   • Quasi Experiment or Collection of Case Studies
     • Participants have on eye covered and gaze at the centre line on the screen then slides are projected either side of the central line for 1/10th of a second
       • 1. Participants held out both hands where they cannot be seen, one hand is put in a certain position and they had to imitate that position with the other hand
       • 2. A visual stimulus was flashed to either the LVF or RVF and the participants had to describe it
       • 3. A visual stimulus was flashed to either the LVF or RVF and the participants had to write the name of it
       • 4. Two different figures were flashed to LVF and the RVF, the participants were asked to draw what they had seen with the left hand then they were asked to say what they had drawn without looking at the drawing

2. Aim...

   • To study the effects of hemisphere deconnection
   • To show each hemisphere has different functions

3. Sample...

   • Oppurtunity
   • Mostly male (at least one female)
   • 11 participants with epilepsy who had a split brain surgery

4. Context...

   • There are a number of structures that join the two hemispheres of the brain allowing exchange of information
     • What would happen if these were artificially seperated
   • Localisation: the extent to which particular jobs are performed by particular parts of the brain
   • Lateralisation: there is a difference between the roles of the left and right hemisphere

5. Conclusion...

   • In split brain patients memory in each hemisphere is independent
   • In split brain patients perception in each hemisphere is independent
   • Split brain patients are not obviously impaired still have intelligence and personality
   • Your brain has plasticity so can change and adapt

6. Results...

   • 1. Participants could not imitate the position of one hand with the other hand unless it is very simple gestures such as a closed fist or fully open hand
   • 2. Participants could only describe objects flashed to the RVF (left side of the brain works language and speech)
   • 3. Participants could only write down the name of objects flashed in the RVF (left side of the brain works language and speech)
   • 4. Participants could only draw what they had seen in the LVF (right side of the brain works creativity) but when asked what they had drawn said what they had seen in the RVF (left side of the brain works language and speech)

7. Evaluation...

   • Strengths:-
     • Data; uses both quantitative (easy comparisons and analysis) and qualitative (detail and reasoning for results obtained)
     • Ethics: no physical or mental harm
     • Reliability: high because there was high control and standardised procedures were used
     • Science: good as used innovative techniques
   • Weaknesses:-
     • Ecological Validity: low because artificial tasks and conducted in a lab
     • Sample: only 11 participants (mostly male) with epilepsy so not represntative
       • Also hard to generalise as participants had the operation at different times in their life so some may have adapted more than others