Friday, January 16, 2015

Animals process visual input at a rate that differs from humans, according to study

The sensory systems of animals play a crucial role in the way that each animal interacts, whether that is intraspecifically (as in locating a mate or fighting over food) or interspecifically, where animals of different species might compete for resources, like light, or if they are engaged in a predator-prey interaction.

The latter is a good example of how the limitations of sensory systems work within the construct of different species: having the ability to track fast-moving objects like prey, or avoid being an unwitting target becomes essential.

Sensory limitations and spacial acuity in animals have been studied before, but the temporal resolution at which the information that an animal perceives hasn't garnered as much scrutiny. The way that animals process information over fine time scales is basic to how they survive in their habitat.

Researchers from the School of Natural Sciences, Trinity College Dublin, Ireland and Universities of Edinburg and St. Andrews set out to study how temporal information (how time is experienced) might be affected by body size and metabolic rate in vertebrates. In a paper titled Metabolic rate and body size are linked with perception of temporal information, scientists give us an idea of what goes on inside the brains of animals as they process what they see.

By using critical flicker fusion (CFF), the research team was able to measure how the brain processes the information.

In a previous piece, I highlighted how members of different species — dogs, cats and birds — perceive refresh rates of televisions and computer screens. Canines require about 70 images per second, birds need roughly 100 of them and we humans only require 16 - 29.

With that in mind, it could give a little context to how animals coordinate visual information — just one part of how sensory systems work in animals.

As the study illustrated, there are two factors that significantly impact how an animal reacts to what's going on around them — body size and metabolic rate.

The findings indicate a couple of things:

  • An animal's perception of time depends on how fast their nervous system can process information in order to react to its environment.
  • Detecting and processing visual information at a high rate would be key for animals that need to respond to visual stimuli swiftly to avoid falling prey to a predator, or to capture prey. Most often these animals have fast metabolisms and are at the lighter end of the weight scale. (Think winged creatures.) The researchers hypothesize that creatures at this end of the spectrum perceive time at the finest of resolutions. In essence, movements and events will appear to unfold more slowly to them.
There's one thing that stuck out in my mind and could be a plausible driving force for the differences amongst the species: Animals, all having different nervous systems, have evolved to adjust to the changes in their respective environments with something in common — conserving energy.

A hummingbird, with their small stature and own methods of locating food, for example, would need to have a higher perception rate than that of the much-larger elephant, as the latter finds their own food sources much differently and would waste a lot of energy by trying to dart around quickly.

Dogs take in visual information about 25% more slowly than human, seeing a light flash about 75 times per second, which translates into time moving at a slower pace for them. Cats see the light flash around 55 times per second.

The implications that this might have on canine training and how we communicate with dogs, if any, is certainly intriguing.

I don't know about you, but the next time I spy a dog stalking a squirrel in their backyard, I think I'll have more of an appreciation for how each animal is experiencing the situation.

Click here to read more on the study.

Lorrie Shaw is a freelance writer -- most recently as a contributor on MLive -- and owner of Professional Pet Sitting. Shoot her an email, contact her at 734-904-7279 or follow her adventures on Twitter.

No comments:

Post a Comment

Thanks for your comment!