| What is post-mortem examinations? | This is when the brain of a dead person is dissected (cut up) so researchers can look at the internal structure of the brain. |
| Why do post-mortum study? | -Spot structural abnormalieis
-Brown et al found that schizophreina suffers have enlarged ventricles in their brains
-Provide evidence for localisation of function |
| What is an EEG ? | -Looks at overall electrical avidity in the brain, picks of signal of neurons together
-Electrodes on the scaps, electrical acitivty reocrd to create patterns of waves, looking at arousal and consciousness |
| Why use EEG? | - Useful for sleep studies
- Look for abnormal wave patterns
- EEG’s can be used as a diagnostic tool |
| What is fMRI? | Uses 3D scans providing information on structual and functional aspects of brain.
Strong magnetic field and radio waves, areas of the brain are more active they are more oxygenated blood flows there. |
| Why do you use fMRI? | - Useful to study the brain during activities/tasks
- Can be used a diagnostic tool (can show areas of the brain that are damaged/diseased) |
| What is ERP? | Event-related potentials - looking at how an EEG wave pattern changes in repsonse to a stimulus.
Specific stimulus - spectific change in wave patterns |
| Why use of ERPs? | - Allows comparison between ‘normal’ individuals and individuals suffering from a disorder eg: depression
- Useful for research into memory (information processing) |
| A strength of post-mortem examination? | -Vital for early understanding of the brain
-Paul Broca and Karl Wernick relied on post-mortem stuidies in establishing links between lanage and the beain and beahviour before neuroimaging was possible
-PM studies were also used to study HM's brain to identify areas of damage, which they associate with his memory deficits
-PM continue to provide useful information |
| A weakness of post-mortum study? | -Causation is an issue
-Observed damage to the brain may not be linked to the deficits under review, but to some underalted traumaa or decay
-Further problem is that PM studies raise etihical issues of ceonsent from the indivudal before death, may not provide consent like HM who lost his ability to form memories and not able to provde consent but it was still conducted
-Challenge usefulness of PM studyies |
| Strength of EEG? | -Real life application due to temporal reolution
-Useful for studying the stage of sleep and in the diganosis of conditions like epilepsy and disorders characterized by random bursts of activity
-Today's EEG technology can acccuratley detect brain actively at a resolution of a single millisecond
-Shows the real life usefulness of the technique |
| Weakness of EEG? | -Information from an EEG is that is it overaly generlised
-The EEG signal is not useful at pinpointing the exact source of neural activity
-Therefore, it does not allow researchers to distinguish between activites originating in different but adjaccent locations |
| A strength of ERP? | -ERP is more specific than EEG
-Derived from EEG measurements, therefore, they have excelleen temporal resolution, especially when compared to techniques like fMRI
-Means that ERPs are frequenly used to measure cognitive functions and deficits such as the allocation of attentional resources and the maintenance of working memory |
| A weakness of ERP? | -Lack of standardisation in ERP
-Makes it difficult to confirm findings
-Further issues is that, in order to establish pure data in ERP studies, backgorund 'noise' and extraneous material must be completley elminated
-This is a problem because it may not always be easy to achieve |
| Strength of fMRI? | -Comparison to other scanning techniques it isn't invase and doesn't use radiation
-If admisinisted correctly it is virtually risk-free, non-invasse and straighted to use
-Produces images that have very highspatial resolution, depicting detail by the millimeter and provides a clear picture of how brain activity is located
-Means that fMRI can safely provide a clear picture of brain activity |
| Weakness of fMRI? | -Expensive
-Poor temporal resolution because there is around a 5 secofn time-lag behind the image on screen and the inital firing of neuronal activity
-This means fMRI may not truly represent moment-to-moment brain activity |
