How is fMRI functional connectivity measured?

How is fMRI functional connectivity measured?

Functional connectivity can be assessed with resting-state functional MRI (rs-fMRI), which measure the blood oxygenation level-dependent signal when subjects are positioned in the scanner in an awake-state without performing any particular task.

What technique is used for fMRI functional MRI?

The high-speed MRI technique, echo-planar imaging provides the basis for most fMRI experiments. The problems inherent to this method and the ways in which these may be overcome are particularly important in the move towards performing functional studies on higher field MRI systems.

How do you measure resting-state functional connectivity?

Resting-state fMRI Methods Resting-state functional connectivity measures temporal correlation of spontaneous BOLD signal among spatially distributed brain regions, with the assumption that regions with correlated activity form functional networks.

What is functional connectivity in fMRI?

Functional connectivity is defined as the temporal dependency of neuronal activation patterns of anatomically separated brain regions and in the past years an increasing body of neuroimaging studies has started to explore functional connectivity by measuring the level of co-activation of resting-state fMRI time-series …

How is functional connectivity measured in fMRI data?

In terms of fMRI data, functional connectivity may be investigated on measurements that are obtained while the subject is passively lying in the scanner (resting state) or on fMRI data recorded during a particular task (e.g., Ebisch et al., 2013 ).

Which is the best tool for functional connectivity?

Functional connectivity refers to the statistical relationship between specific physiological signals in time and are generally assessed using techniques such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG) or magnetic electroencephalography (MEG).

How are blood oxygen levels measured in fMRI?

T1-weighted Contrast BOLD-weighted Contrast 7 Blood Oxygen Level Dependence (BOLD) Neurons Lungs Oxygen CO2 Oxygenated Hemoglobin (DiaMagnetic) Deoxygenated Hemoglobin (ParaMagnetic) Contrast Agent 8 Functional MRI (fMRI) Localized Neural Firing Localized Increased Blood Flow Stimulus Localized BOLD Changes

How is functional connectivity measured in a neural network?

Nodes and Edges. Functional connectivity is quantified using measures of statistical dependence between neural time series. These time series can either be discrete (for example, spike trains) or continuous (for example, LFPs).