Sperry (1968)

Question 1

Background of the study

Answer 1

-Epilepsy is a brain condition brought on by abnormal electrical impulses discharging within the brain, disrupting brain patterns
-In the 1940s ‘split brain surgery’ was developed as a treatment-the corpus callosum is cut so the EI could not spread throughout the brain
-Sperry thought these patients were perfect for research into what each hemisphere of the brain does

Question 2

Lateralisation of function

Answer 2

One side of the brain has a different function than the other

Question 3

Corpus callosum

Answer 3

Fibres that carry the majority of information between the two hemispheres of the brain

Question 4

Contralateral control

Answer 4

The idea that each side of your body is controlled by the opposite side of your brain

Question 5

Commissurotomy

Answer 5

Surgical operation to sever the corpus callosum ‘split brain surgery’

Question 6

Overall aim of the study

Answer 6

To study the functions of separated and independent hemispheres

Question 7

What was the epileptic sample of the study?

Answer 7

11 patients who had undergone a commissurotomy as a treatment for their epilepsy, they were obtained from a surgery from America

Question 8

What was the non-epileptic sample of the study?

Answer 8

Epileptic participants were compared with this group of people who had not undergone the surgery and did not have epilepsy

Question 9

What was the main piece of equipment used?

Answer 9

The tachistoscope

Question 10

What were the controls of the study?

Answer 10

-Objects
-Fixation point
-Symbols/images displayed for 1/10th of a second
-Hands out of view
-One eye covered
-Tachistoscope

Question 11

What happened when objects were flashed to the right visual field?

Answer 11

-Information went to left side of the brain
-They could tell you what they had seen

Question 12

What happened when objects were flashed to the left visual field?

Answer 12

-Information went to the right side of the brain
-They could draw the object they had seen with their left hand
-They could not tell you what they had seen

Question 13

What happened when an apple was flashed to the LVF whilst a key was flashed to the RVF?

Answer 13

-Apple to right brain hemisphere
-Key to left brain hemisphere
-Could tell you they had seen a key
-Could draw an apple with their left hand
-Could not tell you why they had drawn an apple

Question 14

What happened when simple maths problems were flashed to the LVF?

Answer 14

-Information went to right brain hemisphere
-Can draw the answer with their left hand

Question 15

What happened when a photo of a nude pin up was presented to the LVF?

Answer 15

-Laughed, looked embarrassed, turned bright red
-Could not say what they had seen or why they reacted like this

Question 16

What happened when objects were felt by the right hand only and not seen?

Answer 16

-Information sent to left brain hemisphere
-Could tell you what they had felt

Question 17

What happened when objects were felt by the left hand only and not seen?

Answer 17

-Information sent to right brain hemisphere
-Could draw the object with their left hand
-Couldn’t tell you want they felt

Question 18

Conclusions about the left hemisphere of the brain

Answer 18

-Has written and verbal language ability
-Controls the right hand side of the body

Question 19

Conclusions about the right hemisphere of the brain

Answer 19

-Can only communicate non-verbally
-Controls the left hand side of your body

Question 20

What ethical guidelines did Sperry uphold?

Answer 20

Confidentiality, informed consent, deception

Question 21

What ethical guidelines did Sperry break?

Answer 21

Protection from harm

Question 22

Confidentiality

Answer 22

-No published videos of the study
-Participant details kept confidential

Question 23

Informed consent

Answer 23

Consented to participate in study after being approached through their hospital

Question 24

Deception

Answer 24

Participants fully aware of the research

Question 25

Protection from harm

Answer 25

-Participants frustrated when they couldn’t explain why they were saying/drawing certain things
-Potentially embarrassing to not have full capabilities

Question 26

Could the study be considered ethnocentric?

Answer 26

-Sample only obtained from a hospital in America
-However not ethnocentric as studying the brain, which is biological so wouldn’t be influenced by culture

Question 27

Internal reliability

Answer 27

-Participants complete the same tasks
-Easy to replicate due to the high numbers of controls

Question 28

External reliability

Answer 28

-Only 11 participants, so not large enough to establish a consistent effect
-But may not need as many people as biological

Question 29

Internal validity

Answer 29

-Participant behaviour may have been caused by their epilepsy rather than their surgery

Question 30

Population validity

Answer 30

-sample was very specific so potentially not generalisable
-But does it matter due to our natural biology?

Question 31

Ecological validity of visual tasks

Answer 31

The tachistoscope procedure not very realistic as we see things for more than 1/10th of a second so our brain could adapt

Question 32

Ecological validity of tactile tasks

Answer 32

Feeling around and not being able to see your hands is relatively normal

Question 33

What debates does Sperry’s study link to?

Answer 33

-Psychology as a science
-Nature/nurture
-Reductionism/holism
-Usefulness

Question 34

Psychology as a science

Answer 34

-Falsifiable and replicable as can be repeated again in lab conditions and proven false
-The data is very objective based on the participants abilities

Question 35

Nature/nurture

Answer 35

Nature as investigates natural brain abilities rather than influenced by experiences

Question 36

Reductionism/holism

Answer 36

Reductionist as only takes into consideration biological explanations of behaviour

Question 37

Usefulness

Answer 37

Perhaps useful in identifying capabilities for those with brain damage