Predator Vision Project

For this project we had to Create a virtual experience that explores and is inspired by the perceptual world of another life form. This experience should be immersive, complete (scripted for presentation – so have a score or script and be automated or have a team who deliver it).

From the shapeshifter intro we had with Mike Blow we discussed a lot of ideas that we wanted to do for the project but the front runner was to create an experience that gave the participant the sight of a snake.

After watching Planet Earth 2 we were fascinated by the scene that featured the Galapagos snake chasing the Marine Iguana hatchling. This led to extraneous research about that particular to snake to find out about it’s senses and how it was able to hunt the prey. In the scene you can see that the snake is unable to see the iguana when it is still, this is because it can only see animals when they are moving.  

We later found out that the Galápagos racer is a Colour Blind snake (Thomas, 1997) . Most of colour blind snakes have pure-cone retina which allows them to see in photopic vision (Underwood, 1970). This is the vision of the eye under well-lit conditions. In humans and many other animals, photopic vision allows colour perception, mediated by cone cells, and a significantly higher visual acuity and temporal resolution than available with scotopic vision.

With most snakes only able to hunt prey when they are moving we decided to create an experience that would demonstrate this using a frame differencing sketch in arduino that outputted it into greyscale, as the Galagos racer snake is colour blind we believed that using a greyscale sketch would would be more impactful. The way that the frame differencing sketch works is that when a person is moving you can see the outline of them but when they are completely still you are not able to see anything.

We could of found a processing sketch that would of been in colour but there are only 3 different types of snakes that can detect heat which are the boa, python and rattlesnake. These snakes all “have holes on their faces called pit organs, which contain a membrane that can detect infrared radiation from warm bodies up to one metre away. At night, the pit organs allow snakes to ‘see’ an image of their predator or prey — as an infrared camera does — giving them a unique extra sense.” (Fang, 2010)

By interpreting a snake’s eyesight in a black and white frame differencing sketch we have researched the umwelt of the snake and identified it’s “perceptual cues among all the stimuli in its environment and to build up the animal’s specific world with them” (H. Schiller, 1934)  The image below show’s the black and white frame differencing sketch. img_6166-1

To enhance the project, we decided to use virtual reality to fully immerse the participant so that their natural sight was lost and they could only see by the vision of a snake, this was done by combining the frame differencing sketch with a Ketai camera sketch that enabled the code to be programmed for use with the Samsung gear vr. Add code picture

One fascinating piece of information that arose when researching about Snakes what that snakes lack outer ears unlike humans and have inner ears impacting on the sound they hear; they receive sound through their jaws. “Snakes would therefore be expected to have very poor pressure hearing and generally be insensitive to airborne sound, whereas the connection of the middle ear bone to the jaw bones in snakes should confer acute sensitivity to substrate vibrations. “(Christensen, et al., 2012) Hearing in snakes is needed to be at a high level as it “provides vital information about the surrounding environment in most vertebrates, and so sound detection and auditory scene analysis are utilized by animals in many different ways to navigate, avoid predators, find prey and communicate” (Webster et al., 1992).

The sense is that is the most predominant in snakes is their excellent sense of smell, that makes up for the lack of eyesight and limited hearing. “Snakes do their best sniffing, not with their conventional nose (though they do smell through their nostrils, too), but with a pair of organs on the roof of their mouths called the Jacobson’s or vomeronasal organ. To smell through their mouths, snakes rely on tongue-flicking. ” (Bryner, 2016)

References

Bryner, J., 2016. Livescience. [Online] Available at: http://www.livescience.com/32235-can-snakes-smell-anything.html [Accessed 8 December 2016].

Christensen, C. B., Christensen-Dalsgaard, J., Brandt, C. & Teglberg Madsen, P., 2012. Hearing with an atympanic ear: good vibration and poor sound-pressure detection in the royal python, Python regius. Journal of Experimental Biology, pp. 331-342.

Collins, J. & Seigel, R., 1993. Snakes : ecology and behavior. New York: McGraw-Hill. Ficken, R., Matthiae, P. & Horwich, R., 1971. Eye Marks in Vertebrates: Aids to Vision. SCIENCE, 173(4000), pp. 936-939.

Fang, J. (2010) Snake infrared detection unravelled. [Online] Available from: http://www.nature.com/news/2010/100314/full/news.2010.122.html [accessed 15 December 2016]

Goldsmith, S. K., 1986. Feeding behaviour of an arboreal insectivorous snake (Opheodrys aestivus) (Colubridae). 29 ed. London: Southwest Nat.. Henderson, R. W. & Binder, M. H., 1980. The ecology and bahavior of vine snakes (Ahaetulla, Oxybelis, Thelotornis, Uromacer): A review, Milwaukee: Milwaukee Public Museum.

H. Schiller, C. (1934) A stroll through the woods of Animals and Men. New York: International Universities Press, inc. [Online] Available from: https://dle.plymouth.ac.uk/pluginfile.php/625371/mod_resource/content/0/Kruger%2C%20T.%2C%20%282006%29%20Nonsense.pdf [accessed 15 December 2016]

Repérant, J., Rio, J.-P. & Lemire, M., 1992. Comparative analysis of the primary visual system of reptiles. In: C. Gans & P. S. Ulinski, eds. Sensory Integration: Biology of Reptilia . Chicago/London: The University of Chicago Press, pp. 175-240.

Underwood, G., 1970. The Eye. In: S. Thomas, ed. Biology of the Reptilia, Morphology B. New York: Academic Press, pp. 1-98.

Walls, G., 1942. The Vertebrate Eye and Its Adaptive Radiation. New York: Hafner. Webster, D., Fay, B. & Popper, A., 1992. The Evolutionary Biology of Hearing. New York: Springer-Verlag.

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