Ways of investigating the brain

Question 1

what are fMRIs?

Answer 1

detects changes of both blood oxygenation and flow that occurs due to brain activity in specific parts of brain

changes in blood flow. active areas require more oxygen/ produces 3D map of brain

Question 2

what do fMRIs produce?

Answer 2

3-dimensional images showing parts of brain involved in specific mental processes. shows activity 1-4 secs after something occured + accurate within 1-2mm

Question 3

strengths of fMRIs

Answer 3

-** non-invasive:** risk free, doesnt use radiation like PET
- very high spatial resolution: detail by milimetre
- clear picture of how brain activity localised- localisation

Question 4

limitations of fMRIs

Answer 4

• expensive compared to others, only capturing clear image if person still or blurry
• poor temporal resolution: 5 sec time-lag so cant say when sm happens so not rep momemnt to moment brain activity

Question 5

what are Post Mortems?

Answer 5

after death, look at correlation beween brain after death and behaviour before death people likely to be those with rare disorders/unusual deficits

Question 6

what do PET show?

Answer 6

areas damaged within brain examined to establish likely cause of person’s experience + compare to neurotypical to calrify extent of difference

Question 7

strengths of PET

Answer 7

• helps understand key processes in brain: led to devel of** Broca + Wernicke’s** areas
• used to study Tan, provide useful info
• improve medical knowledge so generate hypotheses for further studies

Question 8

limitations of PET

Answer 8

• lack causation: damage may not be due to deficits but related to trauma/decay
• ethical issues: consent eg HM couldnt form memories so no consent, challenges usefulness
• no brain activity (death)

Question 9

what are ERPs?

Answer 9

event related potentials- types of brainwave that are triggered by particular events
similar to EEG but stimulus is presented to p and the activity on screen is of the stimulus

used for experiements

Question 10

what do ERPs do?

Answer 10

• using statistical averaging technique all extraneous brain activity from EEG recording filtered out leaves responses relating to presentation of specific stimuli. leaving ERPs

Question 11

strengths of ERP

Answer 11

• temporal resolution compared to fMRI, take readings every milisecond so real time brain activity instead of passive brain
• used to measure cognitive functions + deficits eg maintence of WM
• specific measurement of neural processes
• cheap + no-invasive

Question 12

limitations of ERPs

Answer 12

• extraneous material must be completely eliminated eg background noise to get pure data which isnt easy to achieve
• low spatial resolution as only focuses on time brainwave is stimulated
• hard to standardised as complex=not same results

Question 13

what are EEGs?

Answer 13

measure electrical activity in brain via electrodes fixed to individuals scalp using skull cap. electical charges detected and presented on screen.

Question 14

strengths of EEGs

Answer 14

• diagnosing conditions eg epilepsy- random bursts of activity in brain/ stages of sleep
• high temporal resolution as detects brain activity at resolution of single milisecond so real world usefulness
• non-invasive as directly over surface of brain
• cheaper compared to fMRI so less strain on NHS

Question 15

limitations of EEGs

Answer 15

• info is recieved from many thousands of neurons, generalised signal
• difficult to know exact source of neural activity so has low spaital activity as cant distinguish where functions localised