Ways Of Studying The Brain

Question 1

What are 4 ways of investigating the brain?

Answer 1

1. Functional magnetic resonance imaging (fMRI) 2. Electroencephalogram (EEG) 3. Event-related potentials (ERPs) 4. Post-mortem examinations

Question 2

Describe fMRIs

Answer 2

Measures changes in blood flow which shows neural activity. When a brain area is more active, it consumes more oxygen so there is increased blood flow.

Question 3

Describe EEGs

Answer 3

Measures general electrical activity in the brain via electrodes which are fixed to the scalp. Small electrical charges are detected and graphed over a period of time

Question 4

Describe ERPs

Answer 4

Record electrical activity of the brain but isolate specific neural responses. They do this by repeatedly presenting a stimulus and averaging the responses. Any extraneous neural activity that is not related to the specific stimulus will not occur consistently and therefore will be filtered out,

Question 5

Describe post mortems

Answer 5

Analysis of a person’s brain after their death. Areas of damage examined to establish the likely cause of the person’s affliction.

Question 6

2 Strengths and 1 Limitation of fMRIs

Answer 6

• Non-invasive (no exposure to harmful radiation or insertion of harmful instruments)
• Produces images with very high SPATIAL resolution which allows for better discrimination between brain regions.
• Poor TEMPORAL resolution. 5 second time lag between image and initial firing of neuron

Question 7

2 Strengths and limitations of EEG

Answer 7

• High temporal validity
• Useful in clinical diagnosis, such as for epilepsy
• Poor spatial resolution. Can only detect activity in superficial and not deep regions such as the hypothalamus or hippocampus
• Not useful for pinpointing the exact location of neural activity as electrical activity can be picked up by neighbouring electrodes.

Question 8

1 Strength and limitation of ERPs

Answer 8

• Can measure the processing of stimuli even in the absence of a behavioural response. They make it possible to monitor the processing of a particular stimuli without requiring the person to respond to them.

In order to establish pure data in ERP studies, background noise and extraneous material must be completely eliminated and this may not always be easy to achieve.

Question 9

What are two strengths and limitations of using post-mortems?

Answer 9

-Allow for a more detailed examination of anatomical aspects of brain that wouldn’t be possible with non-invasive techniques (fMRI and EEG).
- Played central part in early understanding of key processes in the brain before neuroimaging became a possibility.

• Issues with causation- damage may not be linked to deficit under review but to some other trauma
• Ethical issues of consent from before death due to deficits in the brain