A coupled model to jointly predict EEG and optical evoked response changes in rats under varying stimulus patterns

Multimodality functional brain imaging has been gaining importance due to the complementary nature of different imaging modalities. Dynamical systems based models of neural activity and local hemodynamics may offer enhanced spatiotemporal resolution and insight into physiological signals and mechanisms. One major tool for studying brain function is to evoke local responses by repeated application of a stimulus. Under such stimulation neuronal evoked responses show complex habituation to stimuli as the repetition frequency increases beyond 2 Hz. These habituation effects are also reflected in the resulting hemodynamic responses. To understand the relationship between the habituated neural activity and hemodynamics we propose a modeling framework that uses simplified version of an existing neuron model with a control structure enabling habituation prediction and a neurovascular model that captures the relation between neuronal and hemodynamic evoked responses under different stimulus patterns. We report on the accuracy with which this combined model captures the neural and hemodynamic responses across a range of variation in stimulus patterns which includes both frequency and duration variation.