Smart skins: Information processing by lateral line flow sensors

The information processing capabilities of the lateral line system and its potential utility in surveying foreign environments and providing sensory g uidance to autonomous vehicles in dark or highly turbulent conditions is re viewed. The lateral line is a spatially-distributed system of directionally -sensitive sensors that respond to low-frequency water motions created by n earby moving sources, the animal's own movements, the ambient motions of th e surrounding water, and distortions in ambient or self-generated motions c aused by the presence of stationary objects. While lateral line sensors on the skin surface appear to serve behaviors dependent on large-scale stimuli , such as upstream orientation to bulk water flow, other sensors enclosed i n fluid-filled canals appear to subserve behaviors requiring information ab out fine spatial details, such as prey localization. Stimulation patterns a long sensor arrays provide rich information about the location, distance an d direction of moving sources. The lateral line system has also evolved sev eral different mechanisms-static biomechanical filters at the periphery and dynamic neural filters in the central nervous system-for enhancing signal- to-noise ratios in different behavioral contexts, ranging from unexpected e vents of importance (e.g., an approaching predator or prey) to expected eve nts of little relevance (e.g., the animal's own repeated and regular breath ing movements).