FMRI Flashcards
Function of FRMI
Measures blood flow in the brain
What is temporal resolution?
The activity being measured overtime
What is spatial resolution
The space in which activity is being measured
What is single cell recording?
The direct measure of a neuronal activity by recording the activity of a single cell
Invasive-Therefore not used on humans
poor field of view-can only be used on small brains
What is phrenology?
The theory that bumps on the skull reflect on exaggerated traits
What is PET?
Positron emission therapy
Measures metabolic and physiological activity
This is also an invasive technique
Low resolution
Uses isotopes of fluorine
When positron meets electron it creates a gamma ray that can be measured
Example of how imaging is used in neuroscience
PET is used to study patients and localise epilepsy
What is FMRI?
When changes in neuronal activity can give measurable change
There is a collection of around 100-150 MRI scans(1 every 2-3 seconds)
Experimenter changes activity at specific points to perform specific tasks
Scanner has periods of rest between tasks
Participants asked to perform a task and blood flow is measured
Increased blood flow means increased oxyhemoglobin
Indirect measure of the brain
Explain block stimulus and BOLD signal for FMRI
Block stimulus is the period in which stimulus is being presented
BOLD signal is the event related stimulus
Increasing blood flow increases Bold signal and MRI signal
What is the temporal functions of FMRI?
Neural signal is the signal we get from the FMRI
HRF is predicted
Neural signal+ HRF leads to a convolved response
Model of FMRI time series
FMRI time series is the difference between resting state and estimated temporal profile of active state to create a voxel time series
Data analysis of FMRI
Identifying voxels with signal changes to the timing of experiments
FMRI neuronal activity stimulated state properties
Increased blood flow decreased deoxyhaemoglobin Increased cerebral blood volume Lower gradient at vessel Increased signal
FMRI subtraction method
Blood of area of the when stimulated-Blood of area when not stimulated
FMRI application
Woman in Vegetative state is in a non responsive state cannot do anything but the FMRI shows lighting up of certain areas when asked to
