Lecture 5: What is fMRI?

What is fMRI and how does it work?
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Terms in this set (19)
MRI based methods for imaging the axon tracts that form the white matter of the brain

Measures density and motion of water traveling along the myelinated axons

Water normally diffused in all directions but since myelin has a lipid boundary, that boases water to move along the length of the axon

measuring this movement can create images of white matter tracts in the brain
HRFthe way the BOLD signal evolves over time in response to an increase in neural activity is called the hemodynamic response function3 phases of HRF1. initial dip 2. overcompensation 3. undershootcognitive subtraction theoryby comparing the activity of the brain in a task that utilizes a particular cognitive component to the activity of the brain in a baseline task that doesn't, it is possible to infer which regions are specialized for that particular cognitive component Problem: assumption of pure insertions and interactions make imagine data ambiguousfunctional integrationrefers to the way in which different regions communicate with each other; likely to be essential for a full understanding of how cognition is linked to the brainsports and head injury-concussions and subconcussive hits in many sports are suggested to be associated with chronic traumatic encephalopathy (CTE) -Buildup of tau protein, problems with memory, concentration, depression, anger -Stricter policies implemented in some sportsparametriccontinuous dimension, measuring associations between brain activity and variablesassumption of pure insertionassumes brain regions can be inserted without affected functions of other regionsHow does structural MRI work?magnetic pulse briefly aligns H atoms in the brain and records when they return to normal positionA longer neural signal means that the BOLD response is ______ and ______.taller and longer