Neuro - fMRI

True or False: Stimulation of brain regions is accompanied by increased oxygen delivery and increased oxygen consumption at the active region

false

What does the BOLD effect stand for?

blood oxygen level dependent signal

blood oxygen level dependent

True or False: The BOLD signal reflects changes in the ratio of oxyhemoglobin to deoxyhemoglobin

true

True or false: Oxyhemoglobin is paramagnetic

false

Neurovascular coupling describes the phenomenom where capillaries ____ (contract or dilate) when neurons nearby are activated

dilate

Is the fMRI BOLD signal sensitive to changes in HbO (Oxyhemoglobin) or HbR (Deoxyhemoglobin)?

HbR

Blood flow can change via direct action of vasodilators such as ___ and ____

glutamate; nitric oxide

nitric oxide; glutamate

Once capillar HbT increases, penetrating arterioles dilate _____ from the active region

retrograde

Does a negative deoxyhemoglobin signal correspond to a positive or negative BOLD signal?

positive

True or False: Oxyhemoglobin (HbO) promotes dephasing of protons

false

Does a greater BOLD signal corresponds to faster or slower decay (dephasing)?

slower