Perceptual phenomena in destructured sensory fields: Probing the brain's intrinsic functional architectures.

Destructured sensory fields, involving homogenous stimulation with little or no time-varying structure, provide a fertile ground for testing hypotheses about predictive coding in the human brain. Extended exposure to sensory patterns that deviate substantially from the statistics of natural environments can elicit a bewildering range of perceptual phenomena, up to and including vivid oneiric imagery. We illustrate how this large variety of perceptual effects can be understood as the experiential counterpart of auto-generated neuronal dynamics, unconstrained by parameters that tune the waking sensorium. We synthesize the literature on autonomous neuronal activity across multiple spatiotemporal scales with generative models of brain function and evidence from artificial neural architectures. Perception, we argue, emerges from a process of non-random sampling from an intrinsic distribution of hypotheses rather than a direct transfer of information from the world. The imagery that occurs in altered sensory environments is explained as the outcome of an iterative search through internal world models in which the structural typology of percepts reflects the brain's intrinsic functional architectures.