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Sensory Perception Limitations? Unreal!

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Biology 202, Spring 2005
First Web Papers
On Serendip

Sensory Perception Limitations? Unreal!

Rhianon Price

Human beings have five external senses – sight, touch, smell, hearing, and taste. Our interpretation and understanding of the world in which we live is based on these five sensory inputs. What they are able to tell us about the world we inhabit, however, is far from the only data available. While our senses allow us as organisms to interpret our environments, they do not provide us with all the possibilities for sensory input. We are, in fact, limited in comprehension of reality based on the limitations of our flesh.

For example, our senses may be much less sensitive than the same sense of another animal or completely unable to distinguish something in the same way even utilizing the same sense. Bees, for instance, can see infrared, invisible to the human eye ((1)); owls can see mice 150 feet away from them in very dim light ((7)). Dolphins, bats, and some whales, among other animals, use sound to navigate their surroundings through echolocation of objects ((2)). Dogs can tell the difference between two people based on scent alone; dogs and horses can smell emotions such as fear ((3)). A spider can distinguish between strong wind and a bug trapped in its web based on sense of touch ((5)). While we share these senses with these animals, they are able to glean information that, given the same data, we would be unable to duplicate without technological aid or without using another sense.

Even within the scope of human sensory input capabilities there is variation – humans do not have uniform senses. Those entirely lacking certain normal human sensory perceptions aside (like the deaf or blind), some individuals possess certain genetic abnormalities or variations that allow them heightened or lowered senses in comparison to the average person. For example, the average human has approximately 184 taste buds per square centimeter; however, there are those who can boast 425 taste buds per cm2 and those who can only claim around 96 taste buds per cm2 – supertasters and non-tasters, respectively ((4)); the former group has a greater than normal sensitivity to taste, while the latter has a less than normal sensitivity. Furthermore, some women are tetrachromatic rather than the normal trichromatic (which occurs when X chromosomes do not have identical photopigment genes for green or red so they see both pigments of the color), allowing them a broader color palette than most ((6)). Also, individuals may be born without certain smell receptors, leaving them unable to detect certain scents (such as the odor of a skunk, which is most common); this is known as anosia ((8)).

Because of these variations in sensory receptors, human brains are not always able to process certain data that is detectable to others. Our experiences, then, can be seen as not only completely relative, but also limited. With these sensory inabilities seen within our species and compared to others', why, then, do we think we have such a good grasp of the world around us? If there is so much data that we are unable to process, how can we be certain of any truth? How can we find definiteness when there is so much of which to be unsure?

We usually would understand "reality" to be something that all "normal" people can clearly identify and that they share. However, as reality to humans is based on our interpretations of what our senses show us to be extant, but we do not have uniform sensory analysis, can it be argued that individual humans do not share the same reality? While one may accept that what another tells her is in existence based on faith, she can never verify or experience it for herself; while it may be real to others, it is nothing more than a mental construct for her. Furthermore, as we know that there is sensory data available that human beings cannot interpret, as we lack the proper hardware, could it be said that humans lack the ability to experience reality at all? Human reality is not the same as an earthworm's; my reality is not the same as yours. Can reality really be so relative?

It is, however, overly dramatic to claim that we have no perception of reality just because we cannot experience all of it. Our sensory receptors do an entirely adequate job of allowing our species to propagate and thrive. It is a mistake, though, to think that humans have the world figured out – we have discovered so much, but there is still much more that will likely remain forever beyond our comprehension and thus our reach.



1) Seeing, hearing, and smelling the world , from the Howard Hughes Medical Institute.

2) Echolocation, from the Academy for the Advancement of Science and Technology and the Smithsonian Institution.

3) Olfaction , from Cardiff University.

4) Minutes from Me: Tasting , from the Franklin Institute.

5)A Spider's Sense of Touch, from Compton's Encyclopedia On-Line.

6)Yes, men and women do see the world differently, from connected.telegraph.

7)Sense of Sight , from The Yuckiest Site on the Internet.

8)I Can't Smell a Skunk!, from About Children's Health.



Comments made prior to 2007

Hi, i found the essay; 'Sensory Perception Limitations? Unreal!' by Rhianon Price very interesting as my art and studys deal with these theories, i wondered if there are any other philosophers you could help me find that also deal with the theories of reality and perception? ... Paul Starling, 7 February 2007


A. Abdirahman's picture

Good work!

Good work!

David's picture


Have you not felt and KNOWN there were eyes upon you, and at times just where those eyes were focused?

Have you not KNOWN of a predatory or dangerous threat near about?

To what do you base this unspoken yet experienced perception?

Melinda Lloyd's picture

I found this article very

I found this article very interesting. It gives alot on insight to exaclty what we are missing. I never knew or even begun to realize that about the sipder. Our everyday lives do not allow us to live this peaceful to be able to conjer up these "ideas" to be able to find out on our own. Thank you again Rhianon. God Bless wherever you are.

Anonymous's picture

IB students around the world

IB students around the world studying sense perception thank you with all their hearts.