Brain studying techniques

Question 1

MRI (magnetic resonance imagery)

Answer 1

• uses strong magnetic field and radio waves to create detailed image of brain structure
• works by detecting energy from hydrogen atoms emitted by the body because it is abundant in water and fat
• participants lie down in cylindrical scanner and the machine gives high resolution image of brain

ADV: high spacial resolution, not invasive, doesn’t use radiation
DISadv: expensive and can’t be used by people with metal implants, uncomfortable for people with claustrophobia, can’t measure brain activity

Question 2

fMRI (functional MRI)

Answer 2

• builds on MRIs, measures changes in blood oxygenation levels called BOLD (blood oxygenation level dependant) signals to identify active brain regions
• when brain regions are more active, they consumer more oxygen which is detected by the scanner
• participants perform tasks such as solving puzzles or looking at images while the scanner detects activity

ADV: excellent spatial resolution
DISadv: expensive and time consuming, low temporal resolution so it can’t detect rapid changes in brain activity, random movement and thoughts can create noise in data.

Question 3

PET (positron emission tomography)

Answer 3

• uses radioactive tracer to measure emissions from active brain regions
• tracer is often bound to glucose and then injected into the blood stream
• active brain regions consume more glucose, scanner detects brain activity from radiated emission

ADV: helps study structure and function and particularly in understanding neurotransmitter activity
DISadv: poor temporal resolution, is invasive + involves radiation so can’t be used multiple times

Question 4

EEG (electroencephalography)

Answer 4

• measures electrical activity in the brain using electrodes placed on the scalp
• captures brain waves caused by large groups of neurons
• participants wear a cap with electrodes while the machine captures real time activity
• brain waves are patterns of electrical activity in the brain

ADV: high temporal resolution, relatively inexpensive, non invasive
DISadv: low spatial resolution, can not detect activity from deeper regions of the brain