Interactions between visual cortical areas occur in both feedforward and feedback directions along the visual hierarchy, with feedforward interactions carrying signals from sensory areas to higher areas and feedback interactions conveying top-down signals which modulate perception. Several recent works have identified a clear spectral profile: feedforward (bottom up) interactions seem to be associated with oscillations in the gamma band (30-70Hz), while feedback (top down) interactions relate to lower frequencies, in the high alpha or low beta range (8-20 Hz). How these frequency-specific communication channels emerge and shape synchronization across cortical areas remains, however, poorly understood.
In this work, we developed a large-scale computational model of monkey cortex endowed with a laminar structure of cortical areas, to investigate the dynamical mechanism underlying frequency-specific interactions in the visual system. The model spans multiple scales, and each one (local circuit, laminar network, inter-areal interactions, and large-scale cortical network) is anatomically constrained and then tested against electrophysiological observations, which provides novel and valuable insight about their circuit mechanisms. At the large-scale network level, the model is built upon state-of-the-art anatomical connectivity data from the macaque brain. This allows the model to explain observed frequency-dependent functional brain connectivity, its relationship to the underlying structural connectivity, and the emergence of functional hierarchies among visual cortical areas. Our work highlights the importance of multi-scale approaches –with anatomical and physiological constrains at each step –in the construction of large-scale brain models.
Conferenciante: Jorge Mejias, Center for Neural Science, Computational Laboratory of Cortical Dynamics, New York University.
Fecha/Hora: Jueves 14 de abril de 2016, a las 11:00.
Lugar: Aula de Física Computacional del Departamento de Electromagnetismo y Física de la Materia, Facultad de Ciencias.
