Gauging sensory representations in the brain.

The stream of information that enters a sensory system is a product of the ecological niche of an organism and the way in which the information is sampled. The most salient characteristic of this sensory stream is the rich temporal structure that is caused by changes in the environment and self motion of sensors (for example, rapid eye or whisker movements). In recent years, substantial progress has been made in understanding how such rapidly varying stimuli are represented in the responses of sensory neurons of a large variety of sensory systems. The crucial observation that has emerged from these studies is that individual action potentials convey substantial amounts of information, which permits the discrimination of rapidly varying stimuli with high temporal precision.