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SYPH: Physik im Hirn - Physical Approaches to Brain Function
SYPH 1: Physik im Hirn - Physical Approaches to Brain Function
SYPH 1.2: Talk
Wednesday, March 13, 2002, 18:05–18:20, H2
A two rate state model reveals effects of non-stationarity on cross-correlation — •Sonja Gruen1, Alexa Riehle2, and Markus Diesmann3 — 1MPI for Brain Research, Frankfurt/Main, Germany — 2CRNC-CNRS, Marseille, France — 3MPI für Strömungsforschung, Göttingen, Germany
Common to most correlation analysis techniques [1] for neuronal
spiking activity is the assumption of stationarity with respect to
various parameters. However, experimental data may fail to be
compatible with these assumptions which may lead to
falsely assigned significant outcomes. Here we study the
influence of a specific type of non-stationarity, non-stationarity
of rates across trials. Using a two rate state model
where rates are drawn independently for trials and neurons we can show
in detail that non-stationarity across trials may induce co-variance
of rates identified as the source for false positives. We show that
this has specific implications for the ’shuffle predictor’ and might
lead to wrong conclusions. Approaches to compensate for the influence
of non-stationarity across trials by improving the predictor are
presented.
[1] Eggermont J (1990) The Correlative Brain. Springer Verlag