If you rub your closed eyes, you’ll “see” a virtual rainbow of colors, shapes, squiggles, and lines. Those are called phosphenes, and the eye and the brain work together to create these weird little visual blips.
Phosphenes occur when there is no external visual stimulus. That can happen when you close your eyes or when you’re focused on scenery with little to no input as to depth or changes, such as a dark highway at night.
People who spend long periods of time in sensory deprivation or meditation often report seeing visions, which can be chalked up to the appearance of phosphenes.
The presence of physical stimulus to the eye, like pushing on the eyeball, will create temporary phosphenes, and more traumatic events like head injuries can create permanent squiggles.
In these cases, phosphenes are present because the visual centers of the brain are active without the presence of external visual stimuli.
For example, when conscious patients undergoing brain surgery had different areas of their brains electrically stimulated, they reported seeing phosophenes.
In studies of blind people, it’s been found that the appearance of phosphenes happens in different areas along the sight pathway between the eye and the brain, depending on what part of the visual system has been damaged.
Humans aren’t the only ones who can see these dancing bits of light and color—the phenomenon has been observed in animals as well.
I invented the trident and a laser beam once…
Tumblr Tuesday: Monkeys!
The Fauna Foundation is Canada’s only chimpanzee sanctuary and it serves vegan sweet potato poutine to its heartbreakingly sensitive guests. We held and petted a Capuchin monkey this weekend. It reached out its tiny hand and wrapped it around one of our fingers.
An Unnatural History
Possibly the world’s only collection of vintage monkey and ape photographs, some of which are of Capuchin monkeys, the kind that we held and petted this weekend. We cried three times afterward, moved by the experience itself and dizzy over the fact that our life had led to this. An Unnatural History is definitely Tumblr’s best source for monkeys hanging out with dogs.
Monkeys in Art History
Could this diverse selection of monkey-centric art actually be the work of a single, spectacularly talented primate? We hadn’t considered the possibility until we saw our own reflection in the eyes of a Capuchin monkey this weekend. An ageless wisdom was writ into its expression, and in that moment our two species felt closer than we had ever thought possible.
Photos by a primatologist, which is something you’ll wish you majored in after holding and petting a Capuchin monkey. We majored in Classics and assumed we would live a solitary life of the mind. Children were never a part of this picture…but to hold this fragile life in our hands, we were suddenly filled with a love too big for one heart to contain. Primatography includes special bonus shots of sloths and other mammals.
Primate a riffic!
Tiny tiny tiny!
News flash! Even I cannot out-run death…!
Well, that pretty much sums up the internet!
Everyone loves scientific illustration! These beauties, from T. Wingate Todd, were published in Human physiology, especially adapted for dental students, by R. G. Pearce, from 1916. The volume is from Columbia University Libraries and is part of the Biodiversity Heritage Library.
Picture: JULIAN GHAHREMAN-RAD/CATERS NEWS (via Animal photos of the week - Telegraph)
Stop n smell the smelly things
Cracking good time
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