research techniques

Question 1

what does EEG stand for and how does it work?

Answer 1

electroencephalography is a technique which takes measurements of electrical signals generated by the brain through electrodes placed on the scalp

Question 2

what does ERP stand for and how does it work?

Answer 2

event-related potentials is a way of taking and interpreting EEG data through trials where participants are exposed to stimuli

Question 3

what are some of the pros and cons of EEG as a technique?

Answer 3

pros:
- high temporal resolution
- non-invasive
- both healthy and lesioned patients can be tested
- relatively inexpensive

cons:
- low spatial resolution

Question 4

what is the N400 component?

Answer 4

N400 is an ERP component (negative potential at 400 ms) linked to semantic anomalies (“she spread the warm bread with socks”)

Question 5

what is the P600 component?

Answer 5

P600 is an ERP component (positive potential at 600 ms) linked to syntactic anomalies

Question 6

what is the P300 component?

Answer 6

P300 is an ERP component (positive potential at 300 ms) linked to non-semantic, unexpected stimuli

Question 7

what does MEG stand for and how does it work?

Answer 7

magnetoencephalography is a non-invasive method for recording magnetic fields generated by the brain at the scalp

Question 8

what does MRI stand for and how does it work?

Answer 8

magnetic resonance imaging is a technique which makes anatomical images of the brain through the use of magnetic fields that measure blood flow

Question 9

what does fMRI stand for and how does it work?

Answer 9

functional magnetic resonance imaging is a technique that uses magnetic fields to measure activation (blood flow) throughout the brain in response to stimuli

Question 10

what are some of the pros and cons of MRI and fMRI as techniques?

Answer 10

pros:
- high spatial resolution
- non-invasive
- both healthy and lesioned participants can be tested

cons:
- very costly
- poor temporal resolution
- loudness can be disruptive to certain tests (e.g. auditory, speech perception)

Question 11

what does fMRI measure and what does it stand for?

Answer 11

fMRI measures the BOLD response, meaning the blood oxygen level dependent contrast which relates to the concentration of deoxyhemoglobin in the blood

Question 12

what does MMN stand for and how is it elicited?

Answer 12

mismatch negativity is elicited when an “oddball” stimulus, usually auditory, is presented during a research technique such as EEG

Question 13

why do functional imaging data sometimes disagree with lesion data?

Answer 13

• activated regions may reflect the patient’s strategy, not the necessity of a region for performing a task
• lesion studies may be too few to determine concrete conclusions when compared to healthy participants