Measuring coupling asymmetry and time delays in neural oscillators

We address an important problem in neurophysiology concerning the characterization of coupled neural oscillators from experimental data. The approach employs the formal mathematical description of the dynamics of weakly coupled oscillators by the phase model, and the recently developed methods for identification of directionality of coupling and estimation of coupling delays. We study neuron oscillator models with synaptic coupling and diffusively coupled ensembles of neurons, incorporating time delays in coupling. Results of directionality analysis closely reflect the coupling strength asymmetry. In comparison with the standard cross-correlation analysis, the phase dynamics based time delays estimation provides more accurate estimates of coupling delays