Power-law scaling in the brain surface electric potential.
Recent studies have identified broadband phenomena in the electric potentials produced by the brain. We report the finding of power-law scaling in these signals using subdural electrocorticographic recordings from the surface of human cortex. The power spectral density (PSD) of the electric potentia...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2009-12-01
|
| Series: | PLoS Computational Biology |
| Online Access: | http://europepmc.org/articles/PMC2787015?pdf=render |
| _version_ | 1818177418881400832 |
|---|---|
| author | Kai J Miller Larry B Sorensen Jeffrey G Ojemann Marcel den Nijs |
| author_facet | Kai J Miller Larry B Sorensen Jeffrey G Ojemann Marcel den Nijs |
| author_sort | Kai J Miller |
| collection | DOAJ |
| description | Recent studies have identified broadband phenomena in the electric potentials produced by the brain. We report the finding of power-law scaling in these signals using subdural electrocorticographic recordings from the surface of human cortex. The power spectral density (PSD) of the electric potential has the power-law form P(f ) approximately Af(-chi) from 80 to 500 Hz. This scaling index, chi = 4.0+/-0.1, is conserved across subjects, area in the cortex, and local neural activity levels. The shape of the PSD does not change with increases in local cortical activity, but the amplitude, A, increases. We observe a "knee" in the spectra at f(0) approximately 75 Hz, implying the existence of a characteristic time scale tau = (2pif(0))(-1) approximately 2 - 4ms. Below f(0), we explore two-power-law forms of the PSD, and demonstrate that there are activity-related fluctuations in the amplitude of a power-law process lying beneath the alpha/beta rhythms. Finally, we illustrate through simulation how, small-scale, simplified neuronal models could lead to these power-law observations. This suggests a new paradigm of non-oscillatory "asynchronous," scale-free, changes in cortical potentials, corresponding to changes in mean population-averaged firing rate, to complement the prevalent "synchronous" rhythm-based paradigm. |
| first_indexed | 2024-12-11T20:31:47Z |
| format | Article |
| id | doaj.art-f55f843190964fa5be69bf333331e871 |
| institution | Directory Open Access Journal |
| issn | 1553-734X 1553-7358 |
| language | English |
| last_indexed | 2024-12-11T20:31:47Z |
| publishDate | 2009-12-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Computational Biology |
| spelling | doaj.art-f55f843190964fa5be69bf333331e8712022-12-22T00:51:47ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582009-12-01512e100060910.1371/journal.pcbi.1000609Power-law scaling in the brain surface electric potential.Kai J MillerLarry B SorensenJeffrey G OjemannMarcel den NijsRecent studies have identified broadband phenomena in the electric potentials produced by the brain. We report the finding of power-law scaling in these signals using subdural electrocorticographic recordings from the surface of human cortex. The power spectral density (PSD) of the electric potential has the power-law form P(f ) approximately Af(-chi) from 80 to 500 Hz. This scaling index, chi = 4.0+/-0.1, is conserved across subjects, area in the cortex, and local neural activity levels. The shape of the PSD does not change with increases in local cortical activity, but the amplitude, A, increases. We observe a "knee" in the spectra at f(0) approximately 75 Hz, implying the existence of a characteristic time scale tau = (2pif(0))(-1) approximately 2 - 4ms. Below f(0), we explore two-power-law forms of the PSD, and demonstrate that there are activity-related fluctuations in the amplitude of a power-law process lying beneath the alpha/beta rhythms. Finally, we illustrate through simulation how, small-scale, simplified neuronal models could lead to these power-law observations. This suggests a new paradigm of non-oscillatory "asynchronous," scale-free, changes in cortical potentials, corresponding to changes in mean population-averaged firing rate, to complement the prevalent "synchronous" rhythm-based paradigm.http://europepmc.org/articles/PMC2787015?pdf=render |
| spellingShingle | Kai J Miller Larry B Sorensen Jeffrey G Ojemann Marcel den Nijs Power-law scaling in the brain surface electric potential. PLoS Computational Biology |
| title | Power-law scaling in the brain surface electric potential. |
| title_full | Power-law scaling in the brain surface electric potential. |
| title_fullStr | Power-law scaling in the brain surface electric potential. |
| title_full_unstemmed | Power-law scaling in the brain surface electric potential. |
| title_short | Power-law scaling in the brain surface electric potential. |
| title_sort | power law scaling in the brain surface electric potential |
| url | http://europepmc.org/articles/PMC2787015?pdf=render |
| work_keys_str_mv | AT kaijmiller powerlawscalinginthebrainsurfaceelectricpotential AT larrybsorensen powerlawscalinginthebrainsurfaceelectricpotential AT jeffreygojemann powerlawscalinginthebrainsurfaceelectricpotential AT marceldennijs powerlawscalinginthebrainsurfaceelectricpotential |