Quiz #1 METHODS SECTION

Question 1

Single-cell recordings (step)

Answer 1

Electrode placed on or near neuron (invasive), measure action potentials per second, find out how individual neurons code info/fire

Question 2

Event-related Potentials (ERP)

Answer 2

Electrodes placed on skull, measures summed electrical potentials from millions of neurons. Based on EEG recordings but manipulated further. EEG signal AVERAGED over many events (reduce random firing). Timing and amplitude of peaks related to different aspects of the stimulus and task.

Question 3

How to read an ERP

Answer 3

Info is provided by difference in activity between condition A and condition B

Question 4

Advantages and Disadvantages of ERP

Answer 4

ERP is directly related to neural activity, it has great temporal resolution. Disadvantages are that the ERP signal is derived from different sources in the brain and cannot be inferred exactly where they are. Poor spatial resolution

Question 5

How are lesions made in animal lesion studies?

Answer 5

Aspiration lesions (suck tissue out), surgical ablation (removal/destruction of tissue), Chemical lesions, Radio frequency lesions (temporary)

Question 6

What is BOLD a measure of?

Answer 6

Concentration of deoxyhemoglobin in the blood

Question 7

Steps of an fMRI

Answer 7

1. Put subject in big magnetic field
2. Transmit radio waves (about 3ms)
3. turn off radio wave transmitter
4. Receive radio waves (manipulate re-transmission with magnetic fields cause MRI is not a snapshot “polaroid”)
5. Store measured radio wave data vs time
   Process raw data to reconstruct images

Question 8

Hemodynamic response function

Answer 8

Change in BOLD signal over time

Question 9

How does MRI work?

Answer 9

strong magnetic field causes hydrogen atoms to align in same orientation. Radio wave passed through head to spin molecules. Scanner tuned to detect radiation emitted from hydrogen molecules. Different types of tissue emit different RF signals.

Question 10

Units of magnetism

Answer 10

Teslas or Gauss. 1 Tesla = 10,000 Gauss. MRI goes from 3 to 9 (tops). MRI’s are never shut off and would take 30 days for magnetic field to fully decay.

Question 11

What do we mean by “active brain” for fMRI

Answer 11

region shows greater response relative to another condition (baseline). Important to choose correct conditions to measure from or else regions of activity are meaningless.