Researchers estimate how quickly different species sense environmental changes. Documented are small flying creatures - flies and dragonflies among insects, flycatchers among vertebrae, and marine predators. Time flows most slowly in starfish among known species.
At National University of Ireland in Galway , scientists have for the first time compared time to 100 animals that differ in body size, habitat and lifestyle. Time perception is assessed as the speed at which the body is able to register and process changes in the world. The results of the study will be presented at a conference of the British Environment Society in Edinburgh. The
analysis used data collected from a number of experiments that used flashing lights to measure the perception of time. It records how quickly the optic nerve sends messages to the brain.
Flesh flies and dragonflies were recorded as being the fastest to detect changes because their vision allowed them to process changes at a frequency of 300 Hz, or 300 Hz recorded per second. In comparison, a person can only perceive the world at a frequency of 65 Hz. Among vertebrates, the fastest eyes are those of birds, which have a perception frequency of 146 Hz. A salmon's eyes "work" at a frequency of 96 Hz, and a dog's eyes operate at a frequency of 75 Hz. The slowest eye is the starfish, with only 0.7 Hz.
Rapid Sensing benefits both fast-moving species and those that need to track the complex trajectories of their prey. Furthermore, the perception of time is related to the speed at which the environment changes. This could help better understand the interactions between predators and prey and even explain why light pollution affects some species more than others. An unexpected result of
's research is that many terrestrial predators have a relatively slow perception of time. The difference, according to scientists, is that in aquatic environments predators can constantly adjust their position as they chase prey, whereas in terrestrial environments animals cannot adjust once they jump.
's fast time perception also requires a large energy cost, limiting how quickly retinal neurons can charge. Animals that don't need quick vision use this energy for other needs, such as growth or reproduction.
Differences in time perception also exist within a species. This is true even for humans: Some studies show that soccer goalkeepers see changes at a faster rate than the average person, and that coffee can temporarily increase the frequency of perception.
