ways of investigating the brain

Question 1

fMRI

Answer 1

functional magnetic resonance imaging
- mri is a method used to measure brain activity that detects radio waves from changing magnetic fields
- enables researchers to detect which regions of the brain are rich in oxygen/have increased blood flow and thus are active
- can be done while performing tasks, showing which areas of the brain are involved in a particular mental activity

Question 2

strengths of fmri

Answer 2

• unlike other scans (such as pet scans) it doesn’t rely on the use of a radioactive tracers. its risk free and non-invasive
• produces high resolution images that are accurate to the millimetre so provides a clear images of where functions are localised

Question 3

weaknesses of fmri

Answer 3

• expensive compared to other imaging techniques- requires equipment and trained experts
• requires patient to stay still for a clear image which isnt easy for all
• fmri is still imprecise - it can see clusters of neurons but not on the level of indicial neurons

Question 4

electoencephalogram
- EEG

Answer 4

• a record of the brains tiny electrical impulses produced by the brains activity
• by measuring characteristics wave patterns, the EEG can help diagnose certain conditions in the brain.
• electrodes placed on the scalp detect small electrical charges resulting from the activity of brain cells
• when electrical signals from the different electrodes are graphed over a period of time, the resulting representation is called an EEG

Question 5

strengths of eeg

Answer 5

has been extremely useful in investigating a wide range of issues including epilepsy and sleep
- high temporal resolution (as can detect activity in under one millisecond)

Question 6

weakness of eeg

Answer 6

• a general measure, the signal from an individual neuron is not strong enough to detect so only indicates an area where many neurons are firing
• does not allow researchers to differentiate when different areas are firing

Question 7

event-related potentials (ERP)

Answer 7

the brains electrophysiological response to a specific sensory, cognitive or motor event can be isolated through statistical analysis of EEG data

Question 8

strengths of ERPs

Answer 8

• more specific than raw EEG readings
• provides data on responses to specific stimuli

Question 9

weaknesses of ERPs

Answer 9

• different procedures have been adopted (not standardised so difficult to compare and replicate the findings of this study using this technique)
• to be successful, all extraneous interference needs to be eliminated and this is hard to achieve

Question 10

post-mortem brain examination

Answer 10

the brain is analysed after death to determine whether certain observed behaviours during the patients lifetime can be linked to abnormalities in the brain

Question 11

strength of post mortem

Answer 11

vital during the early days of psychology before brain mapping technology was developed e.g Wernicke and Broca

Question 12

weaknesses of post mortem

Answer 12

• cause and effect is a problem: the differences observed can be unrelated to the behaviour
• informed consent: patients lose the ability to consent during their lifetime due to the issues that make them of interest. even those that do not are problematic because then consent is needed from relatives