Bass fishing is not a passive sport, and modern bass-fishing styles involve motion of some sort. It typically involves a high degree of activity on the part of the angler. In fact, bass fishing has itself fueled much of the design of cast-and-retrieve fishing gear.
The vast majority of bass respond only after they see the bait move. Stationary objects mean almost nothing to bass. Even our Berkley ® PowerBait ® and Gulp! ® baits benefit from an occasional twitch of the line to move the bait.
Bass are not passive filter feeders straining food from the water column. They don't graze on aquatic vegetation, and they don't feed on lifeless carrion.
Bass are predators that hunt down live, mobile prey. Sometimes they ambush, and sometimes they stalk. In virtually every case they contend with moving targets. To fit this feeding strategy, bass are endowed with a visual system geared to detecting and analyzing motion.
Bass resolve some aspects of motion considerably better than we do, separating images three times faster. Long after the rotating blade of a spinnerbait becomes a blur to our eyes, a bass would continue to see the moving blade as a distinct image through a much wider range of speeds. With each rotation, the blade would flash on, then off.
Likewise, bass have little trouble seeing each and every swing of even the fastest crankbaits. Not only would the motion of the main body be distinct, so would the movements of the individual components, such as the hooks swinging back and forth.
As with other animals, it is likely that bass are predisposed to look for key motion characteristics while ignoring others. This increases the animal's efficiency in handling pertinent information while ignoring sensory trivia. Even though the complex movements of prey and lures usually involve a number of distinct components, bass are probably most sensitive to only a few.
Still, bass are opportunistic feeders and predators that maintain some measure of feeding flexibility do best. Given the variability in prey movement, it would be counterproductive for bass to develop a strong bias for a narrow set of motions. Too much potential food would sneak by undetected.
One more thing: Bass rapidly lose interest in crankbaits, spinnerbaits and even soft baits moving at a constant speed. We have watched bass swim passively alongside a lure for long periods, only to bolt in for the strike when the lure was suddenly slowed down or speeded up.