A model for the cortico-cortical neural interaction in multisensory-evoked potentials

The authors address the methodological problem of enhancing selective responses from the central nervous system when two (or more) different sensorial stimuli are simultaneously presented to the subject. In particular, contemporaneous visual and somato-sensory stimulation is considered and a model of signal and noise interaction is developed for the processing of the evoked responses. An ARXX (autoregressive with two exogenous inputs) parametric model is introduced and a least squares algorithm is used to determine the selective response of the two neural systems from the overall evoked response. Such an analysis may be also carried out on a sweep-by-sweep basis. Applications of this method are (1) modeling of multisensory potentials; (2) description of facilitation or defacilitation phenomena in multitasking experiments; and (3) analysis of cortico-cortical neural interactions.