Module 4 - tools for discovery

Question 1

what are lesions

Answer 1

• part of the brain is destroyed or severed
• irreversible, rarely done intentionally to humans
• sometimes done to nonhumans to study the brain

Question 2

transcranial magnetic stimulation (TMS)

Answer 2

• simulate lesion safely and temporarily by generating a magnetic field on the surface of the head
• disrupts the brain

Question 3

transcranial direct current stimulation (tDCS)

Answer 3

• apply small current on the surface of the head to affect likelihood of action potentials (increases action potential rate)
• marketed as brain stimulator but it’s not always good

Question 4

electroencephalography (EEG)

Answer 4

• measure electrical activity (waves) in the brain using electrodes on the
• high temporal resolution
• low spacial resolution
• limited to near-surface activity

Question 5

temporal resolution

Answer 5

relating to time
- high is related to continuous measurement of brain activity

Question 6

spacial resolution

Answer 6

• where in the brain the activity is occurring

Question 7

Positron emission tomography (PET)

Answer 7

• tracks blood flow by injecting radioactive tracers
• usually a sugar pill with a bit of radioactivity

Question 8

magnetoencephalography (MEG)

Answer 8

• measure fields near scalp created by neural activity

Question 9

structural magnetic resonance imaging (structural MRI)

Answer 9

• use powerful magnetic fields to obtain 3-D images of internal tissues

Question 10

Functional MRI (fMRI)

Answer 10

• use MRI to monitor blood flow
• BOLD signal (blood oxygen level dependent)
• high spacial resolution
  cons:
• low temporal resolution
• expensive

Question 11

what are the two most commonly used tools for studying the brain

Answer 11

EEG and MRI