Global field power: Time-frequency domain approach

• Autorzy: Duda J. , Imbir K. , Zygierewicz J.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: Classic approach of Global Field Power (GFP) is defined as a function of time, where the GFP maxima are used to determine the latencies of evoked potential components. The GFP corresponds to the spatial standard deviation, and it quantifies the amount of activity at each time point in the field (which consider signal from all electrodes simultaneously). Its results in a reference-independent descriptor of the potential field. This study shows an extension of this method to time-frequency domain. AIM(S): The main aim of this study was to determine time windows for chosen frequency bands suitable for further statistical analysis. The criterion for selection of the time windows should rely on stability of topography of band power. METHOD(S): The frequency enabled GFP relies on estimation of instantaneous band-power and evaluation of its spatial standard deviation. Estimator of band power was obtained by band-pass filtering, followed by rectification of the signal and smoothing of the output. Analogously to the classical GFP, high value of obtained measure indicates spatial variability of power distribution. Changes in its level indicate time-periods of stable topography of power. RESULTS: The method was applied to data recorded in a psychological experiment related to cognitive processing under different emotional conditions elicited by words. Data were analysed in four frequency bands, specific to EEG signal: delta, theta, alpha and beta. Analysis of time course of the GFP in these bands allowed to indicate time periods of stable topography of power. CONCLUSIONS: This study shows that frequency enabled GFP may be used as a simple and intuitive tool for selecting time-frequency regions of interest, suitable for further statistical analysis.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.131

Twórcy

autor

Duda J.

• Division of Biomedical Physics, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland

autor

Imbir K.

• Faculty of Psychology, University of Warsaw, Warsaw, Poland

autor

Zygierewicz J.

• Division of Biomedical Physics, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland