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Monofractal and Multifractal Dynamics of Low Frequency Endogenous Brain Oscillations in Functional MRI
| Content Provider | CiteSeerX |
|---|---|
| Author | Suckling, John Barnes, Anna Wink, Alle-Meije Bernard, Frederic |
| Abstract | Abstract: Fractal processes, like trees or coastlines, are defined by self-similarity or power law scaling controlled by a single exponent, simply related to the fractal dimension or Hurst exponent (H) of the process. Multifractal processes, like turbulence, have more complex behaviours defined by a spectrum of possible local scaling behaviours or singularity exponents (h). Here, we report two experiments that explore the relationships between instrumental and cognitive variables and the monofractal and multifractal parameters of functional magnetic resonance imaging (fMRI) data acquired in a no-task or resting state. First, we show that the Hurst exponent is greater in grey matter than in white matter regions, and it is maximal in grey matter when data were acquired with an echo time known to optimise BOLD contrast. Second, we show that latency of response in a fame decision/facial encoding task was negatively correlated with the Hurst exponent of resting state data acquired 30 min after task performance. This association was localised to a right inferior frontal cortical region activated by the fame decision task and indicated that people with shorter response latency had more persistent dynamics (higher values of H). Multifractal analysis revealed that faster responding participants had wider singularity spectra of resting fMRI time series in inferior frontal cortex. Endogenous brain oscillations measured by fMRI have monofractal and multifractal properties that can be related to instrumental and |
| File Format | |
| Access Restriction | Open |
| Subject Keyword | Response Latency Multifractal Analysis Endogenous Brain Oscillation White Matter Region Echo Time Multifractal Process Hurst Exponent Task Performance Cognitive Variable Fame Decision Right Inferior Frontal Cortical Region Functional Magnetic Resonance Imaging Singularity Spectrum Fractal Process Multifractal Property Fractal Dimension Possible Local Scaling Behaviour Multifractal Parameter Single Exponent Low Frequency Endogenous Brain Oscillation Bold Contrast State Data Grey Matter Complex Behaviour Multifractal Dynamic Persistent Dynamic Singularity Exponent Functional Mri Fame Decision Task Power Law Fmri Time Series Inferior Frontal Cortex |
| Content Type | Text |
| Resource Type | Article |
