Visual stimuli evoke waves of electrical activity that propagate across the visual cortex of freshwater turtles. Analyses using the Karhunen-Loéve method reveal that the spatiotemporal dynamics of the waves encode information about the stimuli. This study used a large-scale mathematical model of turtle visual cortex to understand how cellular elements of the cortex control the generation and propagation of the waves. A combination of excitatory and inhibitory pathways control the origin and speed of the waves. Feedback inhibitory pathways control the duration of the waves. This analysis leads towards a characterization of visual cortex as a dynamical system.