Ways of Studying the Brain

• (AO1) State what MRFI stands for and define it

  Functional magnetic resonance imaging

  • Detects blood flow in brain
  • Use magnetic fields + radio waves to detect changes in blood circulation = as a result of neural activity
  • High active areas of the brain need high amounts of blood, in comparison to low active areas which have lower blood supply
  • Pictures of brain are displayed on 3D FMRI image, highlights parts of brain active in specific mental processes.

  
• (AO3) Give 2 strengths of FRMI

  (+) Good spatial resolution = (best - 1mm) specifically identifies active areas of brain + change in activation over time. Helpful with localisation of function = understand link between behaviour and area (Broca, Wernicke, prosopagnosia)

  
  

  (+) Non-invasive = doesn't require radiation or insertion of instruments. This causes people to be more willing = increase in brain scans = increase in data
• (AO3) Give a limitations of FMRI


  (-) Requires patients to be still in which movement would cause unclear image. For example, children may need to be sedated = issues with consent.
• State what EEG stands for and define it 


  Electroencephalogram

  • Collection of many electrodes attached to a cap, fitted onto scalp with conductive gel
  • Since neurons release electrical impulses, electrodes pick up signals in the form of different waves
  • Amplitude (size of wave) = intensity and frequency (distance between each wave) = speed of activation
  • Responsible for developing understanding of REM (dream) sleep.
  • Is associated with fast desynchronised activity = indicative of dreaming.

  
• State what ERP stands for and define it

  Event related processes

  • Uses same technique as EEG
  • Measures electrical outputs while patients complete tasks e.g. looking at a stimulus and naming them.
• Give a strength of EEG and ERPs

  (+) Non-invasive = no radiation or insertion of instruments and cheaper then FMRI = increases ppts = increases data = increasing overall understanding.
• Give 2 limitation of EEGs and ERPs

  (-) Poor spatial resolution. Unable to provide information on deeper regions (e.g. hypothalamus) = limited in comparison to FMRI.

  (-) Uncomfortable electrodes attached to scalp = unrepresentative readings as patients discomfort may be affecting cognitive responses to situations.
• State what PME stands for and define it (give case study)

  Post - mortem examination

  • Study brain of dead person who displayed particular behaviour when alive that suggested brain damage
  • This method successfully contributed to understanding of many disorders
  • Case study = Iverson examined brains of deceased schizophrenic patients. Found high concentration of dopamine in limbic systems compared to people without schizophrenia = highlights importance of such experiments.
• Give a strength of PME

  (+) Detailed examination of anatomical and neurochemical aspects of the brain which is not possible with other techniques = alot of research into deeper brain regions.
• Give 2 limitations of PME

  (-) Ethical issues = informed consent, did ppt provide consent BEFORE death? Many PME are carried out on patients with severe psychological deficits = cant provide full informed consent, YET a PME could be conducted. Ethical questions surrounding nature of investigation.

  
  

  (-) Extraneous factors may affect results. People die at different ages, death due to different reasons, medication, length of time between death and PME. Makes conclusions of research questionable.
• Define spatial resolution

  Where activity happens (level of accuracy), exact location in space.
• Define temporal resolution

  When activity happened (level of accuracy) - exact location in time