Guest Posted February 7, 2011 Posted February 7, 2011 Then you might find this interesting, Chris. I had read his before but I thought it fit what you described observing. http://rspb.royalsocietypublishing.org/content/276/1664/1949.full "With regard to the functions of eye movements in the natural habitat, chimpanzees and humans may possess different strategies for processing scene information. Given that in humans, close or direct fixation is typically necessary to identify objects in scenes and to perceive their visual details (Henderson & Hollingworth 1999b), the more frequent and wider rotation of eyes that characterizes chimpanzees may represent a strategy for more quickly and widely retaining scene information." http://www.nature.com/news/2007/071203/full/news.2007.317.html "The work doesn't mean that chimps are 'smarter' than humans, but rather they seem to be better at memorizing a snapshot view of their surroundings — whether that be numbers on a screen or ripe figs dangling from a tree. Humans may have lost this capacity in exchange for gaining the brainpower to understand language and complex symbols, says Matsuzawa."
Guest Posted February 8, 2011 Posted February 8, 2011 Just as there are only a few times during the year when the sky is fully illuminated by a full moon, there are only a few times during the year when the sky is really totally black, and even then there are the stars, which to most of us is as good as being inky black, but then we humans are almost never without light now; either electric light or firelight, and so perhaps BF, while functionally nocturnal, might not need any really special adaptations with biochemicals or physiologic changes, and are simply comfortable and used to operating in the dark, and would more acurately be described as 'crepuscular'. After all, seeming to be almost superhuman compared to how modern humans behave in the woods as we stumble around making noise and smellin' up he joint, wouldn't really take much of a superman.
Guest ChrisBFRPKY Posted February 8, 2011 Posted February 8, 2011 Great finds Jodie! Thanks. Since Chimpanzees seem to be better at memorizing a snapshot view of their surroundings, I think it's a safe bet that our larger hairy friends may possess and be using the same mechanism. It's funny to think we may have had a similar ability in the past, but it seems a shame to lose it in order to understand language and symbols. That would seem to lead to another question. If our large hairy friends still possess this ability to process snapshots of their surroundings,(as for me, I'm sure of it) makes me think that language may not be or at least is less likely to be present. Interesting. Chris B.
Guest Posted February 8, 2011 Posted February 8, 2011 They theorize that we lost it, but you know a human hunter will see more in a glance than I will in the woods. I think it's an unlearned trait rather than something we lost. Consider this, they tested people who grew up in a modern world. They might have had different findings if they had tested a Bushman in Africa against a chimp. I guess they didn't think of that when they did their studies.
Guest ChrisBFRPKY Posted February 8, 2011 Posted February 8, 2011 That's a good point. A trained eye would probably test better than average I would think. Chris B.
Guest ajciani Posted February 8, 2011 Posted February 8, 2011 Yes, it is an unlearned trait. I was actually working on my own internal thought processes to re-learn it, and have had some success. Memory of objects and scenes is based on a retention of the description, rather than a "pixel" based image. Humans tend to formulate memories as words, which takes time to process. We also pay attention to details, so we end up looking at something to study and memorize it. Chimpanzees retain a set of objects or a geometric "feeling" for a short time. Humans actually use the same visual processes as the chimps, but take it further. For a human looking at a blue laundry basket containing a blue shirt, a green shirt, and a pair of dark pants, the process is: "pixel" image -> blue grid + blue blob + green blob + dark blob -> blue basket + blue shirt + green shirt + dark pants -> "blue laundry basket containing a blue shirt, a green shirt, and a pair of dark pants" The chimpanzee stops after identifying the objects. It may also retain the "pixel" or geometric image a little longer. The scene is never converted into words: chimps don't use them. So in the memory games that Matsuzawa uses, the humans try to remember the grid as "two", "four", "three", "six", "nine", "eight", "one", "seven", "five". The chimps remember 2 4 3 6 9 8 1 7 5 Humans actually "see" like chimps when they are looking for something. For example, if you are looking for your keys, you don't stare at the counter to ID and memorize a list of the objects sitting on it. You simply glance across it looking for a keys-shaped object. As for the eye shine. Humans do have eye shine, and it is red (reflected from the retina). Their pupils are usually too constricted to see it. As I said, go from 7 mm to 10 mm, and twice the light goes through. My Siamese cat lacks a tapetum lucidum, and his eyes shine (or glow) red, also reflected from the retina. It is only noticeable when his pupils are fully dilated, which happens to be about 10 mm. If his eyes catch the light just right in a dark room, it is a very eerie glow. I have tried to photograph it several times, but he never cooperates.
Guest Posted February 8, 2011 Posted February 8, 2011 (edited) I think I understand now what Vilnoori was talking about when she said she could make her way home by memory in the dark. I do the same thing when I french braid my hair in the back.I've done it so long by feel it messes me up to try to use two mirrors to see what I 'm doing. It's the same thing with checking a laboring patient to see what position and direction the baby's head is in as it rotates down. I can only do that by feel to get my mental map. So with training, I bet you can relearn how to gather info differently. There may be some truth to that old saying, "A picture is worth a thousand words." Edited February 8, 2011 by Jodie
Guest ChrisBFRPKY Posted February 8, 2011 Posted February 8, 2011 ajciani, that's a great post, but I've yet to see a human with eyeshine myself. Maybe it's possible under certain conditions or certain lighting? I don't know. All I know for sure is the white light spots we use will show no eyeshine on a human, but show very bright red eyeshine on a creature. Chris B.
Guest ajciani Posted February 9, 2011 Posted February 9, 2011 Well, if you ever get some drops to force the pupils to dilate open, you might be able to get some eye shine from a human with that spotlight.
17x7 Posted February 9, 2011 Posted February 9, 2011 Genetically altered pentachromatic humans would be able to see through walls, find heat signatures for natural disaster victims at night, all kinds of useful things. Unfortunately, they would have to wear sunglasses during the day just like you do when you get your eyes dilated. I can't see through walls, but I do have extremely good night vision. I also wear sunglasses almost always because of the brightness of normal daylight. I wouldn't have mentioned any of that except that my eyesight doesn't change when my eyes are dilated. I see everything that bright all the time. My ophthalmologist tells me that the size of my pupils is at the upper limit of human range. For a normal eye exam, he doesn't dilate my eyes as there is no point. Sitting in the exam chair, my pupils are as large as most people's after dilation. The only change to my vision when dilated is that my peripheral blurs. 17x7
Guest vilnoori Posted February 9, 2011 Posted February 9, 2011 Another factor is familiarity. These creatures are at home in the forest. They know every path, every tree, every low branch, every bush. They are in it all day, every day, and all night, every night. When we enter the forest it is all unfamiliar territory. I don't turn on the lights to go to the bathroom at night, do you? I know how to get there without turning on the light.
bipedalist Posted February 9, 2011 BFF Patron Posted February 9, 2011 (edited) A Russian researcher's musings on this topic: http://alamas.ru/eng/publicat/Tracht12_e.htm http://alamas.ru/eng/publicat/Shining_add_e.htm http://alamas.ru/eng/publicat/Yowie_red_eyes_e.htm (Yowie) Edited February 9, 2011 by bipedalist
Guest Posted February 9, 2011 Posted February 9, 2011 Another factor is familiarity. These creatures are at home in the forest. They know every path, every tree, every low branch, every bush. They are in it all day, every day, and all night, every night. When we enter the forest it is all unfamiliar territory. I don't turn on the lights to go to the bathroom at night, do you? I know how to get there without turning on the light. I don't think your analogy works. The forest areas that a bigfoot would travel are immense compared to the path to your bathroom.
Guest Posted February 9, 2011 Posted February 9, 2011 (edited) I can't see through walls, but I do have extremely good night vision. I also wear sunglasses almost always because of the brightness of normal daylight. I wouldn't have mentioned any of that except that my eyesight doesn't change when my eyes are dilated. I see everything that bright all the time. My ophthalmologist tells me that the size of my pupils is at the upper limit of human range. For a normal eye exam, he doesn't dilate my eyes as there is no point. Sitting in the exam chair, my pupils are as large as most people's after dilation. The only change to my vision when dilated is that my peripheral blurs. 17x7 That is pretty cool. I got my test done and they think I am a tetrachrome just based on those "find the figure in the dot cards". I can't see anything at night at all. There seems to be a big variation just in regular human eyesight beyond just being near sighted or far sighted. Just out of curiosity, do your eyes reflect light at night if someone shines a flashlight in your eyes? I think someone said that would be the case if you did that to someone with dilated eyes. I don't personally think that's true, but I was just curious if you would take a moment to try it out for us. Better yet, just go outside and sit in the dark awhile and ask a family member or friend if they see your eye shine. Edited February 10, 2011 by Jodie
Guest ajciani Posted February 10, 2011 Posted February 10, 2011 That's chemically dilated eyes. If you shine a flashlight in a person's face, their pupils will normally contract very rapidly. So rapidly that you wouldn't be able to notice the shine. Also, the normal fully dilated diameter (about 7mm) is probably too small to get any shine with a flashlight. Now a camera flash works pretty well. It is usually a good 10 times brighter than the flash light, and is over so quick that the pupil can't respond. Now, here's a shot of my cat in a dim room (sans flash). The bright spots in his eyes are some hanging lamps in another room. He wasn't cooperating all that well, so that's the best shot I could get. At the right angle, his eyes can look about 3 times brighter, and even more red. The pupils are dilated 11 to 12 mm (which allows about 2.5 to 3 times more light through than a human pupil).
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