Studying The Brain

Question 1

What are the 4 techniques used when studying the brain?

Answer 1

Functional magnetic resonance imaging (FMRI)
Post mortem examination
Electroencephalogram
Event related potential

Question 2

How does an FMRI scan work?

Answer 2

• It is a brain scanning technique that measures blood flow in the brain when a person performs a task.
• It is based on the premise that neurones that are active in the brain use the most energy.
• Energy requires glucose and oxygen. Oxygen is delivered in the blood stream attached to haemoglobin and is dissociated at the active neurones so the haemoglobin becomes deoxygenated.
• The FMRI can detect the magnetic qualities deoxygenated haemoglobin has which can be used to create a 3D image highlighting the areas where oxygen disassociation has occurred which allows us to see where the neurones are active in the brain.

Question 3

What is an FMRI temporal and spatial resolution?

Answer 3

Temporal resolution is 1-4 seconds

Spatial resolution is 1-2 mm

Question 4

How does electroencephalogram (EGG) work?

Answer 4

• it is done by attaching electrodes onto the scalp.
• It is based on the premise that information is processed in the brain as electrical activity in the form of action potential or nerve impulses, transmitted along neurons.
• The electrodes measure the electrical activity also knows as EEG patterns which include Alpha, Beta, Theta and Delta waves which determine the brains level of activity.
• The EEG patterns give an indication of brain level activity from the amplitude and frequency of the patterns.

Question 5

What is Event related potentials (ERP)?

Answer 5

• Electrodes are attached onto the scalp
• The researcher looks for onset of brain activity after the onset of the stimulus being presented.
• ERP information is difficult to separate from EEG information so the stimulus is presented many times and an average response is graphed.
• If the onset of brain activity occurs within 100 milliseconds following the presentation of a stimulus it is referred as a sensory ERP as a sensory response is occurring. If the onset of brain activity occurs after 100 milliseconds it is a cognitive ERP as it demonstrates information processing.

Question 6

What is the temporal resolution and spatial resolution of EEG and ERP?

Answer 6

• Temporal resolution: 1 millisecond

- Spatial resolution: greater than FMRI

Question 7

what are post mortem examinations?

Answer 7

-It is a physical study of the brain of a person after they had died who has displayed a particular behaviour while they were alive that suggested possible brain damage.