Discuss how and why particular research methods are used at the biological level of analysis. (22)
Discuss (22) – A considered and balanced review, including a range of arguments, factors or hypothesis. Opinions and conclusions presented clearly supported by appropriate evidence.
Research methods
Research method: Experiments
How are experiments used?
| Seligman – Learned Helplessness Dog Study (Depression) |
| [A] |
Prove that Learned Helplessness can lead to depression. |
| [P] |
- A dog was trapped in an enclosed area where the floor was lined with electrodes.
- The experimenter would activate the electrode once in a while.
- The dog would jump over a low wall to the other side of the enclosed area where no electrodes were on the floor.
- The experimenter raised the wall slowly until it was too high for the dog to jump over.
- Then after a few trials, the experimenter lowered the wall again.
|
| [F] |
- The dog gave the high wall a few attempts.
- But after knowing that it is impossible to jump across, the dog gave up and let itself get electrocuted.
- When the walls were lowered again, the dog did not attempt to jump across.
|
| [C] |
- The dog learnt that he is incapable of jumping across.
- Learn that its are helpless therefore lowering its self esteem.
|
| [E] |
- Low in ecological validity, lab experiment.
- Controlled, no confounding variable.
- Animal experiment can provide insight into human behaviour.
- Unethical, participants did not have rights to withdraw.
- Induced fear and depression into participants.
|
| Sperry – Hemisphere deconnection and unity in conscious awareness |
| [A] |
Investigate behavioural, psychological and neurological consequences when the left and right hemisphere of the brain is disconnected. |
| [P] |
- Subjects were patients who had deconnection surgery to stop epileptic seizure.
- Each hemisphere controls the opposite side of the body.
- They were given a series of tests.
- Test one
- Visual information is presented to the left or right side for 1/10th of a second.
- Eyes will not have time to readjust hence stimulus on the right will be received by the left hemisphere, vise versa.
- Test two
- Present tactile (touch) stimulus to the left or right side.
- Screen is used to cover and remove visual identification.
- Stimulus felt on the left side will be received on the right hemisphere, vise versa.
|
| [F] |
- Object shown on the left side will only be recognized when its shown on the left side again, vise versa.
- Only objects shown to the right visual field can be named verbally or written down.
- Objects shown to the left visual field cannot be named.
- Subjects were shown a Dollar Sign on the left and a Question Mark on the right.
- They were asked to draw what they see with their left hand (the cannot see their left hand), subjects drew a Dollar Sign.
- When asked what they had just drawn, they would tell the experimenter “A Question Mark”.
- If an object was felt by the left hand, it can only be recognized by the left hand again.
|
| [C] |
- Brain function is localised.
- Speech and writing comprehension happens in the left hemisphere.
- Processing of image and visuals happen in the right hemisphere.
- There is a different visual perception and memory storage in each hemisphere.
|
| [E] |
- Made use of patients who underwent hemisphere disconnection surgery as a cure for epileptic seizure, bypassed ethical guidelines of needing to physically harm the subject (even with consent).
- Natural experiment, high in ecological validity.
|
Why are experiments used?
Strengths of Experiment
- Can be repeated, results tend to be more reliable
- Controlled environment, removes confounding variable
- Isolation of IV and DV give a clear cause and effect relationship
- Can always be generalised to a certain extent
- Data easily measured
Weaknesses of Experiment
- Lab environment, low in ecological validity
- May break ethical guidelines
- Lower generalising potential
- [Natural experiment] No control over variables, unpredictable
- Possibility of Demand characteristics
Research method: Case studies
How are case studies used?
| The case study of Clive Wearing (Brain damage) |
| Description |
- Suffered damage in Hippocampus due to a contraction of a virus.
- His disease left him with extensive brain damage (parts of his temporal lobes).
- Suffers from Retrograde and Anterograde amnesia.
- MRI scanning show damage to the hippocampus and some of frontal regions.
- Episodic memory and some of his semantic memory are lost.
- He can still play piano, conduct music and remember his wife.
- He still has his implicit memory including his emotional memory for his wife.
|
| [E] |
- Ecological validity: High, study of a real life case.
- Low potential ability to generalise because cases are individual.
- Ethics: Patient’s name was disclosed under consent.
|
| Milner and Scoville- The Case Study of HM |
| Description |
- HM suffered from epilepsy.
- Went through lesioning to remove temporal lobe.
- Surgeon accidentally removed parts of the Hippocampus (responsible for LTM retrieval).
- Caused anterograde and retrograde amnesia.
- Retrograde amnesia only affected memory up to 11 years before surgery.
- He can remember things 12 years before the accident.
- Discovered that the cortex and hippocampus is connected and years in first grade would not be fully consolidated until first year in sophomore.
- Emotional memory was intact, at the mention of the death of his favourite uncle, he experienced distress.
|
| [E] |
- Ecological validity: High, study of a real life case.
- Low potential ability to generalise because cases are individual.
- Ethics: Patient’s name was kept confidential until he died.
|
Why are case studies used?
Strengths of Case Studies
- Unique studies that would otherwise be unethical to do
- Less likelihood to break ethical guidelines
- Insight into certain areas of psychology that would otherwise be difficult to study
Weaknesses of Case Studies
- Low potential to generalise
- Since it cannot be repeated, results might be unreliable