ABSTRACT
Central sensory pathways construct representations of the external world based on a combination of spatiotemporal patterns of receptor neuron input and a running average of internal activity patterns. In most sensory systems, the relationship between stimulus energy in the external world and the spatiotemporal pattern of receptor neuron activity appears relatively straightforward. For example, spatial relationships of visual stimuli are maintained by spatial patterns of visual receptor cell activity in the retina and subsequent precise retinotopic projections to visual cortical centers. Similarly, auditory stimulus frequency information is extracted by a spatial gradient of frequency sensitivity along the basilar membrane of the cochlea and subsequent precise tonotopic projections to auditory cortical centers. Lateral inhibition along both the visual and auditory sensory pathways helps to more precisely define the specific visual spatial pattern or auditory frequency of the initiating stimulus.
