Neural Mass Model of Human Multisensory Integration

A neural mass model of interacting macro-columns is stimulated to reproduce unisensory, auditory and visually evoked potentials and multisensory (concurrent audiovisual) evoked potentials. These were elicited from patients conducting a reaction response task and recorded from intracranial electrodes placed on the parietal lobe. Important features of this model include inhibitory and excitatory feedback connections to pyramidal cells and extrinsic input to the stellate cell pool, with provision for hierarchical positioning depending on extrinsic connections. Both auditory and visually evoked potentials were best fit using a top-down paradigm. The multisensory response reconstructed from its constituent models was then compared to the actual multisensory EP. Fitting of the multisensory response from constituent models to the actual response required no significant changes to the architecture but did require a decrease in top-down feedback delay. This suggests that multisensory integration, and its related improvement in reaction behavior is not an automatic process but instead controlled by a central executive functioning