BIO: Ways of Studying the Brain

Question 1

Tracking activity in the brain:

Answer 1

• chemists noticed atoms behave differently in strong magnetic fields

Question 2

define magnetic reasonance:

Answer 2

combining the magnetic field with pulses of radio waves causes atoms to ‘flip’
- different radio wave frequencies affected different atoms

Question 3

what are the four different ways of studying the brain?

Answer 3

1. fMRI
2. EEG (Electroencephalogram)
3. ERP (Event-related potential)
4. Post mortem

Question 4

fMRI scan Process:

Answer 4

• person performs tasks inside electromagentic tunnel
• magnetic fields aligns hydrogen nuclei (abundant in blood)
• radio pulse ‘flips’ nuclei, then when they realign, they release energy

Question 5

how are fMRI gradients recorded?

Answer 5

• energy differences (gradients) are mapped using a coil
• these are mapped onto a computer generated frame to produce images
• brighter areas have more blood flow so they are doing more work
• mapping technique is called BOLD: Blood Oxygenation level Dependent activity

Question 6

how are EEGs used?

Answer 6

measures electrical activity in the brain using scalp contacts.
used to diagnose epilepsy (spikes in activity) and Alzheimer’s (reduced activity in certain areas)

Question 7

How do ERPs (event-related potentials) work?

Answer 7

small changes in voltage within the brain can be detected using a ERP machine
- patient repeats an action may times
- we record ‘normal’ baseline readings
- can infer electrical activity was due to the activity
- Sensory ERP- within 100ms of stimulus (detecting)
- Cognitive ERP- after 100ms of stimulus (interpreting)

Question 8

Post Mortem

Answer 8

if we look at brains of people with known impairments while alive, we can see what had gone wrong in their brains.
- Broca used this to learn about a language center (Broca’s areas)
- HM was a good e.g of this (2014)
- Cotter et.al (2001) found low numbers of connecting (glial) cells in depressed patients

Question 9

Evaluation 1 (self-report reliability)

Answer 9

P- More reliability than self-report and non-invasive
E- fMRI, EEGs and ERPs
E- However data is correlational
L- cause and effect

Question 10

Evaluation 2 (need large number of trials)

Answer 10

P- need a very large number of trials and can only see surface levels
E- EEGs, limits how they can be used because it’s very time-consuming
E- However, machine is much cheaper than fMRI, requires less space, etc.
L- Economic benefits

Question 11

Evaluation 3 (post mortems)

Answer 11

P- Post mortems give much more detail
E- much of our early understandings are due to post mortems as all regions are available to study
E- lots of confounding variables: drugs taken before death, diseases, age of brain, etc…
L- Internal validity