WAYS OF STUDYING THE BRAIN

• What is a functional magnetic resonance imaging (fMRI)?


  A brain scanning technique that measures blood flow in the brain when a person performs a task. Works on the premise that neurons in the brain that are the most active use the most energy.

  -requires glucose and oxygen.

  Deoxygenated haemoglobin has a diffident magnetic quality than oxygenated haemoglobin.
• What is the spatial resolution on a fMRI?

  Very high; 1-2mm.
• What is an electroencephalogram (EEG)?


  Works on the premise that information is processed in the brain as electrical activity in the from of action potentials/ nerve impulses, transmitted along neurons.

  -Via electrodes fixed to a skull cap.
• What is the temporal resolution of a fMRI?

  Low; 1-4 seconds after it occurs.
• What is the spatial resolution of an EEG?

  Poor; too generalised.
• What is the temporal resolution of an EEG?

  Very good; every millisecond.
• What is an event-related potential (ERP)?


  Uses similar equipment to an EEG, however a stimulus is presented to a participant and the researcher looks for activity related to that stimulus.

  -Aims to isolate brainwave activity

  -Specific waves for specific neurological events.
• What is the spatial resolution of an ERP?

  Poor.
• What is the temporal resolution of an ERP?


  Very good; 100 milliseconds.
• What is a post mortem examination?

  Where researchers will study the physical brain of a person who has displayed a particular behaviour while they were alive that suggested possible brain damage.

  E.g. Broca's area - Tan

  Allow for comparisons to near-typical brains.
• What is the spatial resolution of a post mortem examination?

  Very high.
• What is the temporal resolution of a post mortem examination?

  None; no brain activity.
• What is a fMRI used for?

  Showing localised brain activity

  -3D map of the brain.
• What is an EEG used for?

  Overall account of brain activity

  Used as a diagnostic tool.
• What is an ERP used for?


  Understand different psychological phenomena

  -Sleeping disorders, Alzheimer's.
• What is the use of a post mortem examination

  Enables researchers to examine deeper regions of the brain e.g. hypothalamus.
• What are 4 strengths of fMRI?

  • No radiation
  • Non - invasive
  • Low risk
  • High spatial resolution.
• What are 3 weaknesses of fMRI?

  • Expensive compared to other techniques
  • Bad temporal resolution - time delay of 4-5 seconds
  • Only measures blood flow, not activity at the neuronal level.
• What are 2 strengths of EEGs?

  • Invaluable for diagnosing some disorders
  • Extremely high temporal resolution.
• What are 2 weaknesses of EEGs?

  • Fairly generalised about the brain past wave types.
  • Can't pinpoint an origin of activity at a neuronal level. Hard to distinguish between areas.
• What are 3 strengths of ERPs?

  • The criticisms of EEGs are addressed by ERPs.
  • More specific as it is EEG analysed.
  • Gives evidence for localised function.
• What are 2 weaknesses of ERPs?

  • Lack of standardised procedure by administering physicians.
  • Not always possible to tune out extraneous data.
• What are 2 strengths of post mortem examinations?

  • Provided an early understanding of brain structure and function
  • Wernicke and Broca both used this.
• What are 2 weaknesses of post mortem examinations?

  • There have been cases (Einstein) where consent was not gained
  • Doesn't tell us a lot about alive brains functioning.