TOTAL AND PARTIAL COHERENCE ANALYSIS OF SPONTANEOUS AND EVOKED EEG BYMEANS OF MULTIVARIABLE AUTOREGRESSIVE PROCESSING

The joint use of fetal and partial coherence between pairs of EEGs sim ultaneously recorded in a standard set, is shown to enhance what is ca used by direct correlation between cortical subsystems and what is ins tead related to the spread of the electromagnetic field. A multi-varia ble autoregressive approach is employed in the computation, giving res ults even for a very short time window, thus allowing coherence to be investigated at the main cortical latencies of evoked potentials. In p articular, when a combined visual and somatosensory stimulation is app lied, cortical interactions are captured in the frequency domain.