If you’ve ever asked yourself that question (or perhaps, “How can that fly react so quickly?”), standby. Researchers at the Trinity College of Dublin, Ireland may have an answer. Apparently, smaller organisms, especially those with higher metabolic rates, can process visual information faster than larger organisms.
So what does this mean? As put by Melissa Hogenboom of BBC News, “Smaller animals tend to perceive time as if it is passing in slow motion.’ This allows them to react and move more quickly than their predators/other larger organisms can follow.
The researchers were able to take advantage of the all-or-nothing firing of neurons in order to test temporal perception. Basically, for the experiments they found the critical flicker fusion frequency (CFF) of animals of many different sizes and metabolisms and compared them. The CFF is defined in the study as “the lowest frequency of flashing at which flickering light is perceived as a constant image.” The higher CFF, the more information the organism can process at a time. (A more in-depth explanation can be found in the journal).
Here’s a good visual of how it all works:
The ability of an organism to track a moving object depends on the time integral over which the individual can obtain its information. This is determined by its ability to resolve temporal information. In cases where an animal, such as a ground squirrel, displays complex movement (a), conspecifics may perceive the individual as moving according to a first-order integral of its actual movement owing to its high temporal resolution abilities (b). However a species with lower temporal resolution abilities, such as a short-eared owl, may perceive the motion as an even higher order derivative of the actual motion, meaning information of prey motion at finer temporal scales is not available to it (c)
*note above caption is from the journal
So the next time you fail miserably at killing that pesky fly, don’t fret. It is not your fault, the fly has actually been adapted to think and react incredibly fast to survive. As put by Graeme Ruxton, one of the co-authors of the study, “…this work highlights the impressive capabilities of even the smallest animal brains. Flies might not be deep thinkers but they can make good decisions very quickly.”