Ways of studying the brain

Question 1

what are the ways of studying the brain?

Answer 1

• functional magnetic resonance imaging (fMRI)
• electroencephalogram (EEG)
• event-related potentials (ERGs)
• post-mortem examinations

Question 2

how does fMRI work?

Answer 2

• detecting changes in both the blood oxygenation and flow that occurs as a result of neural activity in specific parts of the brain
• when a brain area is more active it consumes more oxygen and to meet this increased demand, blood flow is directed to the active area (haemodynamic response)
• fMRI produces 3D images (activation maps)

Question 3

what do activation maps in fMRI show?

Answer 3

which parts of the brain are involved in a particular mental process and this has important implications for our understanding of localisation of function

Question 4

how does electroencephalograms work?

Answer 4

• measures the electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap
• scan recording represents the brainwave pattern that is generated from the action of thousands of neurons, providing an overall account of brain activity

Question 5

who is EEG often used by?

Answer 5

clinicians as a diagnostic tool as unusual arrhthmic patterns of activity may indicate neurological abnormalities such as epilepsy, tumours or some sleep disorders

Question 6

what are ERPs?

Answer 6

using an EEG to isolate a specific sensory, cognitive or motor event and measuring the neural response associated with that event. Researchers are able to remove all the extraneous brain activity from the original EEG reading, leaving only the recording of the specific stimulus or task

Question 7

how does post-mortem examinations work?

Answer 7

• involves the analysis of a person’s brain following their death
• typically this happens with individuals who have rare disorders and thus PME can establish the likely cause by examining the areas of damage with the brain and comparing this to a neurotypical brain.

Question 8

what are strengths of fMRIs?

Answer 8

• unlike PET scans, it does not rely on the use of radiation
• if administered correctly it is virtually risk-free, non-invasive and straightforward to use
• has very high spatial resolution, depicting detail by the millimetre, providing a clear picture of how brain activity is localised

Question 9

what are limitations of fMRI?

Answer 9

• expensive compared to other neuroimaging techniques
• poor temporal resolution ( 5s lag behind image on screen and initial firing of neuronal activity

Question 10

what are strengths of the EEG?

Answer 10

• useful in studying the stages of sleep and in the diagnosis of conditions such as epilepsy(characterised by random bursts of activity) which can easily be detected on screen
• extremely high temporal resolution

Question 11

what are limitations of studying the brain?

Answer 11

• not useful for pinpointing the exact source of neural activity
• doesn’t allow researchers to distinguish between activities originating in different adjacent locations

Question 12

what are strengths of event-related potentials?

Answer 12

• much more specificity to the measurement of neural processes
• excellent temporal resolution
• used to measure cognitive functions and deficits (e.g. allocation of attentional resources

Question 13

what are limitations of event-related potentials?

Answer 13

• lack of standardistaion
• to establish pure data in ERP, background noise and extraneous material must be completely eliminated = may not be easy to achieve

Question 14

what are strengths of post-mortem examinations?

Answer 14

• provides a foundation for early understanding of key processes in the brain

Question 15

what are limitations of post mortem examinations?

Answer 15

• observed damage to the brain may not be linked to the deficits under review but other unrelated trauma or decay
• raise ethical issues of consent from individual before death