Sperry Flashcards
1
Q
Aim
A
To show each hemisphere in split-brain patients:
1) Possesses independent stream of conscious
2) Has its own separate chain of memories that are inaccessible to each other
2
Q
Research Method
A
Quasi
+ : controls = standardised = reliable
- : ✕ establish cause and effect ; ✕ manipulate IV
Design?
3
Q
Sample
A
- 11 severely epileptic ppts
- corpus callosum cut from 5 to 1 yrs prior study
- (at least 1 woman)
4
Q
Variables
A
- DV: performance on visual & tactile tasks
-
IV: hem disconnection or not
> (no control group necessary for comparison)
5
Q
Procedure 1
A
VISUAL FIELD TEST
1) ppts cover 1 eye + stare at fixation point
2) image at far right or left visual field for 1?s
3) asked to name + describe image
6
Q
Procedure 2
A
TACTILE TEST
1) ppts hv both eyes covered
2) object placed in left/right hand
7
Q
Results VFT
A
- object right vf > info to left hem > obj described in speech/writing
- obj left vf > info to right hem > ✕ describe in speech/writing > BUT can use left hand to point to matching obj/can draw
8
Q
Results TT
A
- object placed in left hand ✕ be verbally described BUT ✓ retrieved from bag of objs by same hand
- objects in right hand ✓ verbally described
9
Q
Left Hemisphere
A
- controls language, speech, writing
- receives info ab right body side & can communicate those experiences
- communicates ab general cognitive activity common to both hems
10
Q
Type of Data
A
- Quantitative: able to do task (yes/no)
- Qualitative: reporting not seeing obj, what they saw, why they did smth
11
Q
Right Hemisphere
A
- each hem functions independently & has ✕ knowledge of what other is doing
- each hem has its own
> sensations/perceptions
> learning experiences
> impulses to act
> memory chains inaccessible to other hem
12
Q
Validity
A
- High internal: controlled environment
- Low ecological: unrealistic task looking at fixation point
13
Q
Reliabilty
A
- has been repeated, replicable
- BUT variability between ppts eg. time since commissurotomy (operation) means right brain may hv regained some language ~ extent of each ppts’ condition is diff
14
Q
Sampling bias/Ethnocentrism
A
- all had epilepsy & commissurotomy
- male & female BUT small
- evidence of differences in language and laterisation
15
Q
Ethics
A
- ✓ ethics of exp might be helpful to patients
16
Q
Practical applications
A
- understanding commissurotomy effects
