English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Topographic voltage and coherence mapping of brain potentials by means of the symbolic resonance analysis

MPS-Authors
/persons/resource/persons19647

Frisch,  Stefan
Department Neuropsychology, MPI for Human Cognitive and Brain Sciences, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)

graben_topographic.pdf
(Any fulltext), 246KB

Supplementary Material (public)
There is no public supplementary material available
Citation

beim Graben, P., Frisch, S., Fink, A., Saddy, D., & Kurths, J. (2005). Topographic voltage and coherence mapping of brain potentials by means of the symbolic resonance analysis. Physical Review E, 72(5), 051916. doi:10.1103/PhysRevE.72.051916.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0010-E54C-2
Abstract
We apply the recently developed symbolic resonance analysis to electroencephalographic measurements of event-related brain potentials (ERPs) in a language processing experiment by using a three-symbol static encoding with varying thresholds for analyzing the ERP epochs, followed by a spin-flip transformation as a nonlinear filter. We compute an estimator of the signal-to-noise ratio (SNR) for the symbolic dynamics measuring the coherence of threshold-crossing events. Hence, we utilize the inherent noise of the EEG for sweeping the underlying ERP components beyond the encoding thresholds. Plotting the SNR computed within the time window of a particular ERP component (the N400) against the encoding thresholds, we find different resonance curves for the experimental conditions. The maximal differences of the SNR lead to the estimation of optimal encoding thresholds. We show that topographic brain maps of the optimal threshold voltages and of their associated coherence differences are able to dissociate the underlying physiological processes, while corresponding maps gained from the customary voltage averaging technique are unable to do so.