Neuroimaging mood and emotions

Question 1

Describe the principles of MRI.

Answer 1

Using the H+ atoms spin in different tissue to image

Question 2

What is T2 relaxation?

Answer 2

• occurs as a result of energy transfer between spins (dephasing)
• the energy exchange in the hydrogen atoms in fat is more efficient in water
• hydrogen in fat loses transverse magnetization more rapidly than in CSF

Question 3

What is fMRI used for?

Answer 3

• localization of different neural processes
• correlation between brain response and behavior/mood state
• functional connectivity
• pre-surgical planning

Question 4

What is the BOLD signal?

Answer 4

• Blood oxygen level dependent signal
• vascular response to activation
• HbO2 (oxyhemoglobin) vs dHb (deoxyhemoglobin) has different spins
• increase of O2 metabolism –> increase of dHb –> increase of BF –> increase of HbO2

Question 5

What are BOLD images related to?

Answer 5

Neural activity