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.
  • 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.
  • 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.
  • The dog learnt that he is incapable of jumping across.
  • Learn that its are helpless therefore lowering its self esteem.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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)
  • 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.
  • 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
  • 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.
  • 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