Title
Power spectrum scale invariance quantifies limbic dysregulation in trait anxious adults using fMRI: Adapting methods optimized for characterizing autonomic dysregulation to neural dynamic time series.
Abstract
In a well-regulated control system, excitatory and inhibitory components work closely together with minimum lag; in response to inputs of finite duration, outputs should show rapid rise and, following the input's termination, immediate return to baseline. The efficiency of this response can be quantified using the power spectrum density's scaling parameter β, a measure of self-similarity, applied to the first derivative of the raw signal. In this study, we adapted power spectrum density methods, previously used to quantify autonomic dysregulation (heart rate variability), to neural time series obtained via functional MRI. The negative feedback loop we investigated was the limbic system, using affect-valent faces as stimuli. We hypothesized that trait anxiety would be related to efficiency of regulation of limbic responses, as quantified by power-law scaling of fMRI time series. Our results supported this hypothesis, showing moderate to strong correlations of trait anxiety and β (r=0.45−0.54) for the amygdala, orbitofrontal cortex, hippocampus, superior temporal gyrus, posterior insula, and anterior cingulate. Strong anticorrelations were also found between the amygdala's β and wake heart rate variability (r=−0.61), suggesting a robust relationship between dysregulated limbic outputs and their autonomic consequences.
Year
DOI
Venue
2010
10.1016/j.neuroimage.2009.12.021
NeuroImage
Keywords
Field
DocType
fMRI,Entropy,Control systems,Limbic,Anxiety,Amygdala,Dorsolateral prefrontal cortex,Heart rate variability analysis
Insula,Developmental psychology,Neuroscience,Dorsolateral prefrontal cortex,Psychology,Cognitive psychology,Amygdala,Orbitofrontal cortex,Autonomic dysregulation,Limbic system,Hippocampus,Superior temporal gyrus
Journal
Volume
Issue
ISSN
50
1
1053-8119
Citations 
PageRank 
References 
3
0.45
4
Authors
3
Name
Order
Citations
PageRank
Denis Tolkunov130.45
Denis Rubin291.66
Lr Mujica-Parodi330.45