ways of studying the brain

Question 1

what is fMRI and how does it work?

Answer 1

• fMRI works by detecting the changes in both blood oxygenation and flow that occurs as a result of neural activity in the brain.
  
  • When a brain area more active it consumes more oxygen and to meet this demand blood flow increases to this specific area.
  • fMRI produces 3d images , this has important implications for our understanding of localisation of function.

Question 2

what is a strength and limitation of fMRI?

Answer 2

→ One strength of fMRI is that it does not rely on the use of radiation (PET scans do)
→ If administered correctly they are relatively risk free, non-invasive and straight forward to use. Also produces images that have high spatial resolution, providing a clear picture of how the brain is localised.
→ However a limitation is that fMRI is expensive and has poor temporal resolution due to a 5 second time lag behind the image on the screen and initial firing neuronal activity.
→ Means it might not represent true moment to moment brain activity.

Question 3

what is a EEG, and how does it work?

Answer 3

• EEG measures electrical activity within the brain via electrodes that are fixed to a individual using a skull cap.
• Scan recording represents brainwave patterns that are generated from the action of thousands of neurons.
• EEG often used to diagnose epilepsy and sleep disorders as it detects unusual arrhythmic patters of activity.

Question 4

what are Event Related Potentials (ERPs) and how do they work?

Answer 4

-using a statistical averaging technique, researchers are able to filter out all extraneous brain activity from original EEG recording.
What is left is a ERP, types of brain wave that are triggered by specific events

Question 5

what is a strength and limitation of ERP?

Answer 5

→ Strength of ERP is that they bring more specificity to the measurement of neural processes than could ever be achieved using EEG data.
→ They have good temporal resolution as they are derived from EEG data esp when compared to fMRI.
→ Limitation is that there is a lack of standardisation between research studies, this makes it difficult to confirm findings. To establish pure data all extraneous variables must be eliminated which may not always be achievable.

Question 6

what are post mortem exams?

Answer 6

• Technique involving the analysis of a persons brain after death.
• Individuals who are subject to post mortem are likely to be those who have experienced a rare psychological disorder in their lifetime.
• Areas of damage within brain examined as a means of establishing the likely cause of affliction the person experienced.
• May also involve a comparison with a neurotypical brain.

Question 7

what is a strength and limitation of a post mortem exam?

Answer 7

→ one strength of post-mortem is that it is vital for providing a foundation for early understanding of key processes in the brain.
→ Broca and Wernicke relied on post-mortem studies in establishing links between brain and behaviour, decades before neuroimaging became a possibility.
→ A limitation is that observed damage to the brain may not be linked to deficits under review but some form of trauma or decay.
→ Post mortem studies also raise ethical issues about consent. Participants may not be able to provide informed consent, this challenges the usefulness of post-mortem studies in psychological research.