Three types of state transition underlying perception

The key tenet for understanding brain and mind is that all knowledge of the world derives from perceptions that are created by anticipatory neural activity emerging in the brain. That activity moves the body through the environment while simultaneously predicting the changes in sensory input that accompany actions. Brains learn about the world by assimilating to the sensory consequences of their self-organized intentional actions. The essential problem for neurobiologists is to describe the synaptic mechanisms by which neurons interacting in massive numbers create the patterns of anticipatory neural activity that control behavior. Three mechanisms of pattern creation in neurodynamics are described. First, a transient from perturbation by a stimulus drives cortex from its prestimulus operating point in state space without changing cortical dynamics. This is explicit breaking of symmetry by an imposed forcing function. The pattern of relaxation on return to the prestimulus state gives the evoked or event-related potential. Second, a change in cortical dynamics is induced by a stimulus accompanied by reinforcement. This change is a structural bifurcation, in which a permanent change takes place in the connectivity by modifications of synapses in learning. Third, the change that accompanies an act of perception is a state transition by which a sensory cortex jumps from a receiving state to a transmitting state and then back again. The transitions are quick enough to enable cinematographic sampling of rapidly changing environments. The state transition is spontaneous symmetry breaking. A hypothesis is offered that every sensory cortex supports a mesoscopic attractor landscape, which sensitizes the cortex to anticipated classes of stimuli, and that the limbic system regulates the three types of change by generating actions that bring input and up-date the attractor landscapes in creative trial-and-error learning. State transitions in perception 2 Walter J Freeman