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Neuronal shot noise and Brownian 1/f2 behavior in the local field potential.

Milstein J, Mormann F, Fried I, Koch C - PLoS ONE (2009)

Bottom Line: We demonstrate that human electrophysiological recordings of the local field potential (LFP) from intracranial electrodes, acquired from a variety of cerebral regions, show a ubiquitous 1/f(2) scaling within the power spectrum.We develop a quantitative model that treats the generation of these fields in an analogous way to that of electronic shot noise, and use this model to specifically address the cause of this 1/f(2) Brownian noise.The model gives way to two analytically tractable solutions, both displaying Brownian noise: 1) uncorrelated cells that display sharp initial activity, whose extracellular fields slowly decay in time and 2) rapidly firing, temporally correlated cells that generate UP-DOWN states.

View Article: PubMed Central - PubMed

Affiliation: California Institute of Technology, Pasadena, California, United States of America. milstein@caltech.edu

ABSTRACT
We demonstrate that human electrophysiological recordings of the local field potential (LFP) from intracranial electrodes, acquired from a variety of cerebral regions, show a ubiquitous 1/f(2) scaling within the power spectrum. We develop a quantitative model that treats the generation of these fields in an analogous way to that of electronic shot noise, and use this model to specifically address the cause of this 1/f(2) Brownian noise. The model gives way to two analytically tractable solutions, both displaying Brownian noise: 1) uncorrelated cells that display sharp initial activity, whose extracellular fields slowly decay in time and 2) rapidly firing, temporally correlated cells that generate UP-DOWN states.

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Power law and scaling exponent in local field potentials recorded from the human cerebral cortex.Top: Exemplary power spectrum of local field potentials recorded from a micro-wire in the temporal lobe. Middle: The scaling exponent (here α = 2.04) was determined by a linear least-square fit of the log-log power spectrum. Bottom: Scaling exponents (mean±stand. dev.), averaged across micro-wires for different brain regions. FL: frontal lobe α = 1.92±0.29; TL: temporal lobe α = 2.02±0.33; PL: parietal lobe α = 2.03±0.28; OL: occipital lobe α = 2.05±0.10.
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pone-0004338-g001: Power law and scaling exponent in local field potentials recorded from the human cerebral cortex.Top: Exemplary power spectrum of local field potentials recorded from a micro-wire in the temporal lobe. Middle: The scaling exponent (here α = 2.04) was determined by a linear least-square fit of the log-log power spectrum. Bottom: Scaling exponents (mean±stand. dev.), averaged across micro-wires for different brain regions. FL: frontal lobe α = 1.92±0.29; TL: temporal lobe α = 2.02±0.33; PL: parietal lobe α = 2.03±0.28; OL: occipital lobe α = 2.05±0.10.

Mentions: For analysis, the data was down-sampled to 7 kHz using an anti-aliasing filter. The power spectral density was estimated by applying Welch's method to consecutive 5-sec segments and subsequently averaging over the entire 10 min (Fig. 1). The scaling parameter a was determined as the slope of a least-square linear fit of the double-logarithmic power spectrum. To diminish the influence of amplifier roll-off, the linear fit was restricted to a frequency range of 1 to 400 Hz.


Neuronal shot noise and Brownian 1/f2 behavior in the local field potential.

Milstein J, Mormann F, Fried I, Koch C - PLoS ONE (2009)

Power law and scaling exponent in local field potentials recorded from the human cerebral cortex.Top: Exemplary power spectrum of local field potentials recorded from a micro-wire in the temporal lobe. Middle: The scaling exponent (here α = 2.04) was determined by a linear least-square fit of the log-log power spectrum. Bottom: Scaling exponents (mean±stand. dev.), averaged across micro-wires for different brain regions. FL: frontal lobe α = 1.92±0.29; TL: temporal lobe α = 2.02±0.33; PL: parietal lobe α = 2.03±0.28; OL: occipital lobe α = 2.05±0.10.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2629847&req=5

pone-0004338-g001: Power law and scaling exponent in local field potentials recorded from the human cerebral cortex.Top: Exemplary power spectrum of local field potentials recorded from a micro-wire in the temporal lobe. Middle: The scaling exponent (here α = 2.04) was determined by a linear least-square fit of the log-log power spectrum. Bottom: Scaling exponents (mean±stand. dev.), averaged across micro-wires for different brain regions. FL: frontal lobe α = 1.92±0.29; TL: temporal lobe α = 2.02±0.33; PL: parietal lobe α = 2.03±0.28; OL: occipital lobe α = 2.05±0.10.
Mentions: For analysis, the data was down-sampled to 7 kHz using an anti-aliasing filter. The power spectral density was estimated by applying Welch's method to consecutive 5-sec segments and subsequently averaging over the entire 10 min (Fig. 1). The scaling parameter a was determined as the slope of a least-square linear fit of the double-logarithmic power spectrum. To diminish the influence of amplifier roll-off, the linear fit was restricted to a frequency range of 1 to 400 Hz.

Bottom Line: We demonstrate that human electrophysiological recordings of the local field potential (LFP) from intracranial electrodes, acquired from a variety of cerebral regions, show a ubiquitous 1/f(2) scaling within the power spectrum.We develop a quantitative model that treats the generation of these fields in an analogous way to that of electronic shot noise, and use this model to specifically address the cause of this 1/f(2) Brownian noise.The model gives way to two analytically tractable solutions, both displaying Brownian noise: 1) uncorrelated cells that display sharp initial activity, whose extracellular fields slowly decay in time and 2) rapidly firing, temporally correlated cells that generate UP-DOWN states.

View Article: PubMed Central - PubMed

Affiliation: California Institute of Technology, Pasadena, California, United States of America. milstein@caltech.edu

ABSTRACT
We demonstrate that human electrophysiological recordings of the local field potential (LFP) from intracranial electrodes, acquired from a variety of cerebral regions, show a ubiquitous 1/f(2) scaling within the power spectrum. We develop a quantitative model that treats the generation of these fields in an analogous way to that of electronic shot noise, and use this model to specifically address the cause of this 1/f(2) Brownian noise. The model gives way to two analytically tractable solutions, both displaying Brownian noise: 1) uncorrelated cells that display sharp initial activity, whose extracellular fields slowly decay in time and 2) rapidly firing, temporally correlated cells that generate UP-DOWN states.

Show MeSH
Related in: MedlinePlus