week 3

Question 1

A researcher acquires a whole-brain BOLD imaging sequence of 8 minutes duration with a TR=2000ms. How many sequential brain volumes would be in the acquisition?

Select one:
240 
420
480
1

Answer 1

240

Question 2

How long is the typical delay between the onset of neural activity and the resulting peak of the hemodynamic response measured with fMRI?

Select one:
4 to 8 seconds 
4 to 8 millseconds
1 second
500 millseconds

Answer 2

4 to 8 seconds

Question 3

Which of the following statements accurately describes an attribute of the hemodynamic response in activated regions during a stimulus of 30 seconds duration?

Select one:
a. Small undershoot of signal at stimulus offset

b. Small dip of signal 4-8 seconds after stimulus onset
c. Large undershoot of signal prior to stimulus offset
d. Initial summation of signal and sustained plateau

Answer 3

Initial summation of signal and sustained plateau

Question 4

Which of the following experimental strategies can be used to identify regional brain responses associated with a functional component of a complex task?

Select one:
a. Restrict acquisition of BOLD images to times when the functional component is strongest

b. Collect BOLD signal changes form many different tasks with the functional component in common and perform pairwise contrasts between all the tasks
c. Contrast signal changes between two independently performed tasks that are very similar except that only one includes the functional component of interest
d. Use a region of interest approach to constrain analysis to regions likely to be involved in the functional component of the task

Answer 4

c. Contrast signal changes between two independently performed tasks that are very similar except that only one includes the functional component of interest