title: A unifying principle underlying the extracellular field potential spectral responses in the human cortex.
abstract: Electrophysiological mass potentials show complex spectral changes upon neuronal activation. However, it is unknown to what extent these complex band-limited changes are interrelated or, alternatively, reflect separate neuronal processes. To address this question, intracranial electrocorticograms (ECoG) responses were recorded in patients engaged in visuomotor tasks. We found that in the 10- to 100-Hz frequency range there was a significant reduction in the exponent χ of the 1/f(χ) component of the spectrum associated with neuronal activation. In a minority of electrodes showing particularly high activations the exponent reduction was associated with specific band-limited power modulations: emergence of a high gamma (80-100 Hz) and a decrease in the alpha (9-12 Hz) peaks. Importantly, the peaks' height was correlated with the 1/f(χ) exponent on activation. Control simulation ruled out the possibility that the change in 1/f(χ) exponent was a consequence of the analysis procedure. These results reveal a new global, cross-frequency (10-100 Hz) neuronal process reflected in a significant reduction of the power spectrum slope of the ECoG signal.
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel; Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel;
authors: Ella
authors: E
authors: Podvalny
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel; Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel;
authors: Niv
authors: N
authors: Noy
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel;
authors: Michal
authors: M
authors: Harel
authors: Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York; Department of Neurosurgery, Hofstra North Shore LIJ School of Medicine and Feinstein Institute for Medical Research, Manhasset, New York;
authors: Stephan
authors: S
authors: Bickel
authors: Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, Israel;
authors: Gal
authors: G
authors: Chechik
authors: Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute, Orangeburg, New York; and Department of Psychiatry, Columbia College of Physicians and Surgeons, New York, New York.
authors: Charles E
authors: CE
authors: Schroeder
authors: Department of Neurosurgery, Hofstra North Shore LIJ School of Medicine and Feinstein Institute for Medical Research, Manhasset, New York;
authors: Ashesh D
authors: AD
authors: Mehta
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel;
authors: Misha
authors: M
authors: Tsodyks
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel; rafi.malach@gmail.com.
authors: Rafael
authors: R
authors: Malach
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001307:Auditory Perception / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology / Q000601:surgery; D005260:Female; D065818:Gamma Rhythm; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests; D021641:Recognition, Psychology / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D014796:Visual Perception / Q000502:physiology*
keywords: 1/f; ECoG; electrophysiology; narrow-band gamma; power spectrum