Distinguished Lecture Series: Stephen L. Macknik (Phoenix)
I will discuss the role of feedback in visual masking, visual awareness and attention. Our analysis reveals constraints for feedback mechanisms that limit their potential role in visual masking, and in other general brain functions. I will propose a feedforward model of visual masking, and provide a hypothesis to explain the role of feedback in visual masking and general visual processing. I will review the anatomy and physiology of feedback mechanisms, and propose that the massive ratio of feedback versus feedforward connections in the visual system may be explained solely by the critical need for top-down attentional modulation. I will discuss the merits of visual masking as a tool to discover the neural correlates of consciousness, especially as compared to other popular illusions, such as binocular rivalry. Finally, I will propose a new set of neurophysiological standards needed to establish whether any given neuron or brain circuit may be the neural substrate of awareness. Professor Stephen Backnik, Barrow Neurological Institute, Phoenix All are welcome!
