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Computational Intelligence and Neuroscience
Volume 2010 (2010), Article ID 393019, 12 pages
http://dx.doi.org/10.1155/2010/393019
Research Article

Decoupling Action Potential Bias from Cortical Local Field Potentials

1Institute for Systems Research, University of Maryland, College Park, MD 20742, USA
2National Institute for Applied Sciences, 69100 Villeurbanne, France

Received 17 April 2009; Revised 10 September 2009; Accepted 4 November 2009

Academic Editor: Zhe (Sage) Chen

Copyright © 2010 Stephen V. David et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Neurophysiologists have recently become interested in studying neuronal population activity through local field potential (LFP) recordings during experiments that also record the activity of single neurons. This experimental approach differs from early LFP studies because it uses high impendence electrodes that can also isolate single neuron activity. A possible complication for such studies is that the synaptic potentials and action potentials of the small subset of isolated neurons may contribute disproportionately to the LFP signal, biasing activity in the larger nearby neuronal population to appear synchronous and cotuned with these neurons. To address this problem, we used linear filtering techniques to remove features correlated with spike events from LFP recordings. This filtering procedure can be applied for well-isolated single units or multiunit activity. We illustrate the effects of this correction in simulation and on spike data recorded from primary auditory cortex. We find that local spiking activity can explain a significant portion of LFP power at most recording sites and demonstrate that removing the spike-correlated component can affect measurements of auditory tuning of the LFP.