Schemas & Cognitive Neuroscience (AQA AS Psychology)

The role of schema

• Schemas are shortcuts which

  • facilitate the speedy processing of information

  • stop the mind from becoming overwhelmed by environmental stimulation 

• Schemas allow people to predict what may happen and are based on previous experience e.g.

  • 'I've been on a beach holiday before so I know to pack lots of SPF'

• Schemas act as a mental framework for the interpretation of incoming information e.g.

  • 'I can see lots of car brake lights on which means I'm in for a long wait in a traffic jam...'

• Schemas are unique to the individual but many schemas will be shared e.g.

  • Everyone has a 'cat' schema but only specific person will have a specific 'my pet cat called Fluffy' schema

• Schemas may be simple and concrete (e.g. a cat schema) or complex and abstract (e.g. a 'freedom' schema)

• As people get older their schemas become more multi-layered and sophisticated

• Babies are born with simple motor schemas for innate behaviours e.g. sucking

• As people get older schemas become more complex and sophisticated

• Culture affects schemas as it shapes experiences

The emergence of cognitive neuroscience

• Cognitive neuroscience (CN) investigates the relationship/interaction between cognition and neural mechanisms, brain chemistry and brain structure 

• The origins of CN lie in the mid-19th century with the discovery that Broca's area (part of the frontal lobe) is linked to speech production

• New technology e.g. fMRI and PET allow researchers to explain the neurological basis of mental processes for example:

  • Maguire et al. (2000) found increased volume of grey matter in the posterior hippocampi of London taxi drivers using MRI technology

    • Thus, this part of the brain is localised to spatial navigation

  • Raine et al. (1997) found via PET scans that impulsive murderers under-utilise their pre-frontal cortex when making decisions

    • This finding may explain the nature of their unpremeditated crimes 

• Recently the expanded focus of CN has included the use of computer-generated models, which, in effect, 'read' the brain, leading to mind mapping techniques (brain 'fingerprinting')

• In healthcare, computer models and mind mapping can be used diagnostically and during surgery e.g. 

  • To determine the best surgical approach to remove brain tumours

  • To diagnose and treat traumatic brain injuries and conditions such as Parkinson's disease

  • To guide surgeons whilst they perform a procedure (rather like the sat-nav on a car)

• CN has been successfully implemented in the quest to understand mental disorders e.g. the link between the parahippocampal gyrus and OCD

Evaluation of schemas & cognitive neuroscience

Strengths

• Bartlett (1932) established the validity of schemas with his study of cultural schematic interference on memory:

  • Bartlett told his participants (male Cambridge University students) the 'War of Ghosts', a Native American folk tale 

  • The story contained details that were culturally unfamiliar to the participants e.g. canoes, seal-fishing, ghosts fighting, spirits inhabiting living people

  • The participants re-told the story to fit their cultural schema by changing some details e.g. canoes became 'boats'; paddling became 'rowing'; they also omitted unfamiliar elements e.g. no mention of ghosts at all; place names were ignored

  • Bartlett concluded that memory is affected by cultural schemas which overlay the original information by filling in gaps and making assumptions

• CN employs a range of clinical, and scientific methods and measures to establish links between brain and cognition

  • The use of such methods means that research in this field is reliable as it can be used to test specific theories and hypotheses e.g. localisation of brain function

Limitations

• One of the main issues with schema theory is the difficulty in defining exactly what a schema is

  • A schema is an example of a mental framework which has no clear parameters and will differ from person to person (e.g. my schema for 'house' will contain details and ideas which are unique to me, dependent on my experience)

    • If there is no clear consensus as to what a schema is, then the theory lacks usefulness

• Brain-imaging technologies are not infallible: Bennet & Miller (2010) reviewed the reliability of fMRI and found that:

  • some fMRI machines may be affected by potential errors in calibration

  • external factors, such as noise and light can affect the accuracy of the measurement

  • researchers themselves can be a source of error depending on how well they handle the equipment

  • participants may introduce a source of error: their cognitive state will vary over time, with differences in attention and arousal

    • This means that using the test-retest method for checking reliability may not produce similar results to the first time of testing