Week 5.1 fMRI Flashcards
what does an fMRI measure
changes associated with blood flow, the assumption that cerebral blood flow and neuronal activation are coupled
what is the BOLD principle
this is how you map the neural activity in the brain and spinal cord. This is blood-oxygen-level dependent, and accounts for the hemodynamic response.
why is BOLD the preferred method
because no injection or implementation
what is true of blood with a higher oxygen content
that more O2 is susceptible to magnetic responses, so it shows up more
neural activity is associated with
increased blood flow
what happens to brain after activation
there is a 2 second post activation lighting up, and then it peaks at 4-6 seconds.
when was the BOLD method created, and what is it correlated to
1990s and EEG/MEG
how does an fMRI work
same as MRI, for alignment. With a stable magnetic field
what is used to deflect
RF pulses, and you visualize differences between arterial and venous blood, and oxygen saturation
what is a voxel
three dimensional rectangular area of the brain that is 1-5mm depending on the size of the scan
average, 1 voxel equals ___ neurons and ____ synapses
few million neurons and 10s of billions of synapses
what is the timecourse
the response to signal over time, or the activity in the voxel
colors are the
activated voxels
what are the criticisms of fMRI
there is a high rate of noise, due to head movements, and decreased neural activity from doing to the same thing, or getting bored.
what did scanning a dead salmon show us
that there is still areas of the brain that will light up, even in a dead salmon
what is the clinical use of fMRI
surgical planning
effects of tumors, stroke, head injury
what is the research use of fMRI
learning about the sensory processing, tasks, learning, memory and language
how is fMRI used in PT research
brain in pain and mechanisms of MT
what did the article by Martucci show us
that you can track parts of the brain that light up with invoked pain from a stimulus or movement, and neurophysiologic pain from watching things.
what did fMRI show in terms of structural change
chronic pain with grey matter loss
what about functional changes
allodynia (pain with brush of a feather)
what did Louw show in his article
that education about pain can decrease the amount of lighting up the brain does
what did Moseley show
with education about pain, the brain becomes calmer
what did Dr. Sparks show us
that there is less of a pain stimulus in the brain following a t-spine manip, when stabbed in the finger with a needle
results of Dr. Sparks paper
there is a decreased pain perception, there is decreased activation in the brain in the pain areas (cerebellum, amygdala, thalami, periaqueductal grey, insular cortex,…) fowling the t-spine manip
