Evaluation

• A strength of fMRI's is that unlike the PET scan, it does not rely on the use of radiation. if it is administered correctly, it is safe and risk free and non-invasive and straightforward to use.
• fMRI's strength - also produces images which have a very high spatial resolution, depicting the brain in great detail of its localisation(upto mm).
• Limitation of fMRI includes that it is expensive compared to other neuroimaging techniques. it has poor temporal resolution because there is around a 5 second time lag behind the image on screen and the initial firing of neuronal activity. suggesting it may not represent moment to moment brain activity.
• Electroencephalogram strength includes - that is had been useful when investigating sleep patterns and the diagnosis of conditions such as epilepsy which a disorder characterised by random bursts of activity in the brain which can easily be detected on the screen.
• Strength of electroencephalogram is also that unlike fMRI's, EEG technology has extremely high temporal resolution. today, it has been able to detect brain activity in the millisecond range which shows its real world usefulness.
• A limitation of electroencphalogram includes its generalised nature of the information received. The EEG signal is not useful in pinpointing the exact source of neural activity therefore it does not allow researchers to distinguish between different areas of the brain.
• Event-related potentials strength includes that they bring much more specificity to the measure of neural processes than EEG. They have excellent temporal validity when compared to neuroimaging techniques such as fMRI's meaning they are frequently used to measure cognitive functions and deficits such as the allocation of attentional resources and maintenance of working memory.
• A limitation of event related potentials includes that they are not always reliable and can be affected by external factors. Critics have pointed out a lack of standardisation in event related potentials methodology between different research studies which can make it difficult to confirm findings. it may also be hard to achieve no extraneous variables and background noise so it may not be able to establish pure data.
• Post-mortem examinations strength includes that it is vital to have in providing a foundation for early understanding of key processes in the brain. Broca and Wernicke both relied on post-mortem studies to establish links between language and behaviour decades before neuroimaging became a possibility. post-mortem studies were also used in HM's case to identify areas of damage which can be associated with memory deficits.
• Limitation of post mortem examinations may include the cause of an issue to not be related to the deficits under review but to an unrelated issue. post mortem studies may also raise ethical issues of consent from the individual before the death. informed consent may not be provided eg. in the case of HM.