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Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. [1] [2] This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. [3]
Main limitations of fMRS are related to signal sensitivity and the fact that many metabolites of potential interest can not be detected with current fMRS techniques. Because of limited spatial and temporal resolution fMRS can not provide information about metabolites in different cell types, for example, whether lactate is used by neurons or by ...
When fMRI was developed one of its major limitations was the inability to randomize trials, but the event related fMRI fixed this problem. [2] Cognitive subtraction was also an issue, which tried to correlate cognitive-behavioral differences between tasks with brain activity by pairing two tasks that are assumed to be matched perfectly for ...
Functional magnetic resonance imaging data. Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions.
The model includes an interaction term between a psychological variable (task design) and physiological variable (the time series of a brain region). If the interaction term can explain the brain activation of another brain region after taking into account the main effects of the psychological and physiological variables, then it implies a task ...
Functional MRI FABBER FABBER is a Bayesian model fitting tool intended for use in task modelling of ASL data.: FEAT Model-based FMRI analysis with straightforward but powerful GUI: data preprocessing (including slice timing correction, MCFLIRT motion correction and PRELUDE+FUGUE EPI unwarping); FILM GLM timeseries analysis with prewhitening; registration to structural and/or standard space ...
Resting state fMRI (rs-fMRI or R-fMRI), also referred to as task-independent fMRI or task-free fMRI, is a method of functional magnetic resonance imaging (fMRI) that is used in brain mapping to evaluate regional interactions that occur in a resting or task-negative state, when an explicit task is not being performed.
Parametric statistical models are assumed at each voxel, using the general linear model to describe the data variability in terms of experimental and confounding effects, with residual variability. Hypotheses expressed in terms of the model parameters are assessed at each voxel with univariate statistics.