title: A unified statistical model for the human electrocorticogram.
abstract: OBJECTIVE
  Extracellular field potentials (ECFs) generated in the cerebral cortex span a vast range of spatiotemporal scales. The process(es) leading to this large dynamic range remain debatable. Here we propose a novel statistical description of the amplitude spectrum of the human electrocorticogram (ECoG).
  
  
  METHODS
  Spectral analysis was performed on long-term recordings from epilepsy patients undergoing pre-surgical evaluation with intracranial electrodes. Amplitude spectra were fit with a multi-component Gaussian model on semi-logarithmic axes.
  
  
  RESULTS
  The Gaussian formulation provided excellent fits to the data. It also suggested how the changes accompanying the sleep-wake cycle and certain epileptiform transitions could be understood by variation in the parameters of the model.
  
  
  CONCLUSIONS
  The proposed continuum model synthesizes several previous observations regarding the statistical structure of the resting human ECoG. It offers a conceptual platform for understanding the EEG changes accompanying the sleep-wake cycle and pathologically hypersynchronous behaviour.
  
  
  CONCLUSIONS
  Statistical characterisation of the spectral distribution of field potentials yield insight into the cortico-cortical interactions that underlie the summated cortical ECFs comprising the ECoG. Such insight is relevant for a synoptic understanding of major state changes in the brain that are diagnosed in clinical practice by visual inspection of the ECoG.
authors.affiliation: Department of Neurology, University of Texas Health Science Centre, Houston, TX, USA. Electronic address: Giridhar.P.Kalamangalam@uth.tmc.edu.
authors.forename: Giridhar P
authors.initials: GP
authors.lastname: Kalamangalam
authors.affiliation: Department of Neurobiology, University of Texas Health Science Centre, Houston, TX, USA.
authors.forename: Mircea I
authors.initials: MI
authors.lastname: Chelaru
authors.affiliation: Department of Neurology, University of Texas Health Science Centre, Houston, TX, USA.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Slater
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology / Q000503:physiopathology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D012894:Sleep Stages / Q000502:physiology*
keywords: EEG; Epilepsy; Log normal distribution; Power law; Synchronisation