Ways Of Studying The Brain Flashcards
Medical Techniques
-Techniques for investigating the brain are often used for medical purposes in the diagnosis of illness.
-The purpose of scanning in psychological research is often to investigate localisation- to determine which parts of the brain do what
FMRI
-Functional magnetic resonance imaging detects changes in both blood oxygenation and flow that occur due to neural activity in specific brain areas
-When a brain area is more active it consumes more oxygen and blood flow is directed to the active area (haemodynamic response)
-FMRI produces a 3D image showing which parts of the brain are active and therefore must be involved in particular mental processes.
A03 FMRI (Risk Free + High Spacial Resolution)
E- Unlike other scanning techniques (e.g. PET) FMRI does not rely on the use of radiation and is safe. It also produces images with high spatial resolution, showing detail by the millimetre.
E- This means that FMRI can safely provide a clear picture of how brain activity is localised.
A03 FMRI (Expensive + Poor Temporal Resolution)
E- FMRI is expensive compared to other techniques. It has low temporal resolution because of a 5-second lag between initial neural activity and image.
E- This means FMRI may not truly represent moment-to-moment brain activity.
EEG
-Electroencephalogram measures electrical activity within the brain via electrodes using a skull cap.
-The scan recording represents the brainwave patterns generated from thousands of neurons. This shows overall brain activity
-EEG is often used as a diagnostic tool
-Shows brain activity in a general state
A03 EEG (Practical Uses + High Temporal Resolution)
E- EEG has contributed to our understanding of the stages of sleep. It has high temporal resolution- brain activity in one millisecond.
E- This shows the real-world usefulness of the technique
A03 EEG (Information Is Generalised + Source Not Pinpointed)
E- The EEG produces a generalised signal from thousands of neurons. It is difficult to know the exact source of neural activity.
E- Therefore EEG can’t distinguish the activity of different but adjacent neurons.
ERP
-Event-related potentials- electrodes are attached to scalp and a stimulus is presented. Researcher looks for activity related to that stimulus.
-Stimulus is presented hundreds of times and average response is graphed (averaging).
A03 ERP (Specificity + Good Temporal Resolution)
E- Measures of neural processes more specific with ERP’s than EEG’s. ERP’s have excellent temporal resolution, better than FMRI.
E- This means that ERP’s are frequently used in cognitive research.
A03 ERP (Lack Of Standardisation + Background ‘Noise’)
E- Lack of standardisation makes it difficult to confirm findings in studies involving ERP’s. Background ‘noise’ and extraneous material must be completely eliminated.
E- These issues are a problem because they may not always be easy to achieve.
Post-Mortem Examinations
-A technique involving the analysis of a person’s brain following their death.
-Areas of the brain are examined to establish the likely cause of a deficit or disorder that the person experienced in life.
-This may also involve comparison with a neurotypical brain in order to assess the extent of the difference.
A03 PME (Localisation + Medical Research)
E- Broca and Wernicke both relied on post-mortem studies. Used to link HM’s memory deficits to damage in his brain.
E- This means they continue to provide useful information.
A03 PME (Knowing Causation + Ethics)
E- Observed damage in the brain may not be linked to the deficits under review. Post-mortem studies raise ethical issues of consent after death (e.g. HM).
E- This challenges their usefulness in psychological research.
