Sperry - Split Brain Flashcards
Aim 1
Each hemisphere has its own conscious awareness
Aim 2
Each hemisphere has its own memories that are inaccessible to the other
Which research method was used? Why?
Quasi experiment, having a split brain wasn’t manipulated by the researchers. Hemispheres were already disconnected to reduce severe epilepsy.
What other type of study can this be classed as? Why?
A collection of case studies due to the in-depth research and progress carried out on a small group
Was a control group required?
No because the function and abilities f the visual fields was already known for the non-spilt brain individuals
Sample number and qualities
11 patients that had undergone an extensive midline section of the corpus callosum to control their severe epilepsy that couldn’t be controlled by medication
Why did the participant have one eye covered?
So the visual stimulus can only be received by the correct visual field
How and where were the visual stimuli presented?
The images were projected on a screen on either side of the centre point for 1/10 of a second
Why 1/10 second?
Too fast for the eye movements to get the information in the wrong visual field
To which hemisphere would the information travel to if… presented to the right visual field… presented to the left visual field
- The left hemisphere - response was verbal
2. The right hemisphere - could draw with their left hand
Where did the tactile tests take place?
In a gap below the screen so the patient couldn’t see their hands
How were the tactile stimuli presented?
By placing objects in their hands and placing other object on the floor
What is this conclusive apparatus called?
Tachistoscope
What happened when visual and tactile stimuli were presented to the the right hand side of the body?
They could describe the stimulus in speech and writing
What happened when visual and tactile stimuli were presented to the left hand side of the body?
They reported a bright flash and couldn’t describe what was presented. However, they could point to the matching picture with their left hand.
What happened when a $ was presented to the left visual field and a ? to the right visual field?
When asked to draw the symbol they’ve seen they drew the $ with their left hand without looking. When asked what they’d drawn they’d report a ?
When “foot” (LVF) and “ball” (RVF) were presented in different visual fields what happened?
They couldn’t say the full word but could draw the foot and say “ball”
What was the DV?
Ability to perform a variety of visual and tactile tests
What happened if the object was placed in the right hand?
It can be described in speech and writing and found in a grab bag by the same hand
What happened when objects were placed in the left hand?
They took wild guesses as to what it was
What happened when the examiner put pressure on one part of the hand and asked to repeat it on the same hand?
They were accurate in locating the same point on the same hand
What happened when the examiner put pressure on one part of the hand and asked to repeat it on the other hand?
They couldn’t accurately locate the point
Conclusion 1
People with split brains have two separate visual inner worlds, each with its own train of visual images
Conclusion 2
Split brain patients have a lack of cross-integration where the second hemisphere here isn’t aware of the first hemisphere
Conclusion 3
Split brain patients seem to have two independent streams of consciousness, each with their own memories, perceptions and functions
