- A lot of research in cognitive psychology (CP) happens in labs
- Scientific and reliable - has great control over variables
- This type of research doesn’t tell us much about the world - it has LOW ECOLOGICAL VALIDITY
- Take place in a natural situation - MORE ECOLOGICAL VALIDITY
- Less control over variables
- Involve making observations of a naturally occurring situation
- They have HIGH ECOLOGICAL VALIDITY - but they are not massively reliable, as uncontrolled variables can affect the results.
- Experimenter has little control over the variables & P’s can’t be randomly assigned to conditions.
- Can now be carried out during a cognitive task. e.g. MRI scans have been used to show the blood flow in different brain areas for different types of memory tasks.
- Provide support for the cognitive approach
- Use patients’ behaviour to test a theory
- Hard to make generalisations
- Individual differences between people mean that one subject may respond in a way that is totally different from someone else.
Case study of HM - Milner et al (1957)
Study of HM - Milner et al (1957)
- HM was a patient with severe and frequently epilepsy.
- His seizures were based in the hippocampus
- In 1953, doctors decided to surgically remove part of that brain round this area.
- Operation reduced his epilepsy, but lead him to memory loss
- He could still form STM's, but was unable to form new LTM’s. E.g. he could read something over and over without realising that he had read it before.
- Could still talk and show previous skills (procedural memory)
- From tests, they found HM’s episodic memory (past events) and semantic memory (knowledge e.g. word meanings) was affected more that his procedural memory
- The results of non-human studies can be applied to human cognitive abilities. E.g. discovering whether chimpanzees can learn language helps psychologists develop theories about how humans learn language
- There can be many differences between humans and animals that results can be explained wrongly. E.g. you might conclude that chimpanzees can’t learn a spoken language because they lack the cognitive abilities. But its actually more likely to be because they lack physiological attributes, like a voice box.
KEY STUDY: Study of language within chimps - Gardener & Gardener (1969)
Study of language within chimps - Gardener & Garde
Method: Washoe (a chimpanzee), was raised like a human child and taught American Sign Language (ASL)
Results: By the end of the 22nd month of the project, Washoe had learnt at least 34 signs Conclusion:
- The development in language in the chimp appeared to follow the same patterns as language developed in children (both speaking and ASL)
- Washoe learnt language at similar rates to children of the same age.
- She didn’t learn Grammar
- Ethical considerations - Washoe was taken from the wild and deprived of other chimps for companionship
- External Validity - its not possible to accurately generalise results from the study of a chimp to the study of human children.