Sperry Flashcards
Define lateralisation of function
Different parts of your bran have different jobs
Define Corpus Callosum
This is a bundle of nerves that connects the two hemispheres
Define controlatéral control
This means that the right hemisphere of the brain controls the LHS
The left hemisphere of the brain controls the RHS
Define Commissurotomy
The removal of the corpus callosum (the split brai surgery)
What was the aim of Sperry
To study the functions of serrated and independent hemispheres
Describe the sample used in Sperry
11 patients who had already experienced a commissurotomy prior to the study
Opportunity sample
All participants had a history of severe epilepsy which had not responded to drug therapy
Outline the conclusions Sperry made about the left hemisphere of the brain
-If an image was shown in the right usual field (left hemisphere) the subject was able to say what they had seen and could also find it with their right hand from an array of objects
Outline the conclusions Sperry made about the RIGHT hemisphere of the brain
If images were shown in the left visual field (right hemisphere) the subject was unable to name it but could draw it with their eyes closed with their left hand. They could also identify what the object was from an area of pictures
Outline the procedure used by Sperry
Visual information was presented by projecting images on a screen in front of the object. The subject would sit at the table with hands hidden from their view behind the projection screen. Tactile information would be presented to either the left or the right hand or to both hands
Participants had to remain in silence unless they wee asked questions by the researcher
Outline the procedure of the VISUAL INVESTIGATIONS by Sperry (one visual field)
-These involved showing one stimulus at a time to one visual field or showing two stimuli simultaneously to different visual fields
-These tests required the subject to cover up one eye and then they were told to look at a fixation point in the centre of the screen
-The image was then presented for 1/10th of a second so that it would remain in the periforol vision
Outline the procedure of Sperry for BOTH VISUAL FIELDS
-The subject would look at the fixation point on the screen while two images were flashed up simultaneously either side of the pont
-The participants were then asked too say what they had seen
-Then be given a pen in their left hand to draw what they had just seen
How long were the images flashed up on the screen for
1/10th of a second
-This is so that the image was in the periforol vision of the participants so that it would only go to one half of the brain
Outline the procedure of the Tactile investigations
-The subjects hands are hidden from view behind the screen, The subject s then asked to find an object corresponding to that flashed up on screen
-The object is placed in one hand without the subject being able to see what they are holding, they are then asked to say what they had been given
-The object is placed in one hand without the subject being able to see wat they are holding and they are then asked to point at what they have been given
Both hand tactile investigations
-The subject works with their hands out of sight, the subject is given two objects one in each hand and then the objects are taken away. They are then asked to find the bectes by touch from a pile of objects. The subject is asked o say what they had just held
Outline what was found when an image was flashed in the right visual field
-Went to the left hemisphere
-particpants were able to name out loud what was flashed u on th screen
Outline what was found when an image was flashed in the left visual field
-Went to the right hemisphere of the brain
-Participants were able to draw what thy had seen
Patricia’s were nt able to verbally name the object and hey didnt know why they drew it
Outline what happened when different visual stimuli were flashed up in each field
Appl- right visual field
Key-left visual field
Aple went t the left hemisphere f the brain
-Could name out our what they had seen
Key went to the right hemisphere of the brain
-Participants were able to draw it but didn’t know why they drew it
Outline what Sperry found when a simple mathematical Robles was flashed in the left visual field
-This would result in it going to the right hemisphere
-Consequently participants were able to point to the correct answer but not know why
Outline what was found when a photo of a nude pin-up was presented to the left visual field
-went to the right hemisphere of the brain
-Participants laughed out loud but didn’t know why they laughed
Outline what the left hemisphere does
Language
-writin/ saying anything
Outline what the right hemisphere does
This does creative thinking
-drawing
Outlne what happened if objects were felt by the left hand only
-This information would go to the right hemisphere due to controlatéral control
-Particpants were able to draw what was held or identify it from pictures
-They thought they weren’t holding anything
Outoine what happened whe the participants felt an object in ther right hand
-It would go to the left hemisphere of the brain
-name out loud what they were holding
Outline the name of the projection device
Tachistoscope
