Alice in Wonderland syndrome

AliceSyndrome.png“‘What a curious feeling!’ said Alice; ‘I must be shutting up like a telescope.’” “’Curiouser and curiouser!’ cried Alice (she was so much surprised, that for the moment she quite forgot how to speak good English); ‘now I’m opening out like the largest telescope that ever was!’”
Lewis Carroll, ‘Alice’s Adventures in Wonderland’

There are many illnesses and issues that can cause the sensory anomalies, but one of the most interesting is Alice in Wonderland Syndrome (AIWS). The typical symptoms for AIWS are Micopasia (objects appear small) and Macropasia (objects appear large). In addition, body parts sometimes seem to be larger or smaller. Individuals with AIWS often describe their perception of the world like looking through the wrong end of a telescope.

AIWS was identified by British psychiatrist John Todd in 1955, as a “singular group of symptoms intimately associated with migraine and epilepsy, although not confined to these disorders.” Todd named the syndrome after Lewis Carroll’s book, Alice’s Adventures in Wonderland. Carroll (Charles Lutwidge Dodson) reported “bilious headache” (migraine) in his diaries, and the effects of AIWS: “… experienced, for the second time, that odd optical affection of seeing moving fortifications, followed by a headache.”

Here’s some of what we know about AIWS.

  • Cause: AIWS is not considered optical problem or hallucination. It is likely caused by an issue (such as blood flow) in the parietal lobe where perception of the environment is processed.
  • AIWS triggers: infections, migraine, stress and drugs (some cough medicines), brain injury are some of the more common.
  • AIWS in Children: Studies show that between 6 and 10 percent (perhaps a bit more) of children have an onset of AIWS at an average of 8.5 years of age with many growing out of the syndrome in adulthood. In 65% of cases AIWS occurred in children under 18 years of age.
  • Migraine is the first cause of AIWS in adults (27.6%) and the second in children (26.8%).
  • Symptom spectrum: Micopasia (objects appear small) and Macropasia (objects appear large) are the most common distortions caused by AIWS, but other symptoms include a perception that body parts are larger or smaller, that the individual is falling through or merging with the floor. In addition, other senses such as odor and taste are sometimes distorted.
  • Other symptoms reported in AIWS: kinetopsia, auditory hallucinations and verbal illusions, hyperacusia/hypoacusia, dyschromatopsia, zoopsia, and complex visual hallucinations.

In a study of 166 cases of AIWS the most common causes were:

  • Migraine – 27.1%
  • Infections – 22.9%
  • EBV – 15.7%
  • Brain lesions – 7.8%
  • Medicament – 6%
  • Drugs – 6%
  • Psychiatric disorders – 3.6%
  • Epilepsy – 3%
  • Peripheral nervous system disease – 1.2%
  • others – 3%

There’s some speculation that AIWS may have provided inspiration to some of the arts such as writing and painting. A host of artists are known to have suffered from migraines including Carroll, Picasso, Emily Dickinson, Vincent Van Gogh, Thomas Jefferson, and Gustav Mahler.

Web Applications
None

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Field of View

Field of view is the angular extent of what can be seen with the eye. Various animals have different visual fields. Predators generally have more forward facing with binocular oriented vision, whereas prey have side facing visual fields with greater range (for defensive vision). Eyes positioned on the sides of the head is common in prey species, and increases an animal’s total field of view, but it’s often at the expense of sharper binocular vision.

A deer’s field of view can reach 280 degrees, a Rabbit’s field of view can be 360 with just a small blind spot for a short distance behind their head, but with limited binocular vision. A cat has a 200 degree field of view, but with an amazing 140 degrees of binocular vision. Nature has evolved and found advantage in many variations.

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Human’s have general static view of about 135 to 180 degrees horizontally, with about 120 degrees of binocular vision. Ho ever, with eyeball rotation (about 90 degrees) the field of view extends to 270 degrees. In addition, vertical field of vision for humans is about 50 degrees in the upper visual field and 70 degrees in the lower visual field.

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Peripheral vision is a part of vision that occurs outside the very center of gaze. There is a broad set of non-central points in the visual field that is included in the notion of peripheral vision.

In addition field of view is, in a way, limited by the fovea, the part of human eye responsible for sharp central vision (the only part of the retina that permits 100% visual acuity), which is only about two degrees of field. Our wide, 120 degree field of view for binocular vision is the basis for stereopsis and is important for depth perception, he remaining peripheral 60–70 degrees does not provide binocular vision.

Web Development Application

Currently the applying knowledge of field of view for Web development is only of minimal importance, understanding the limits of a foveal view is more important. But as our use and understanding of virtual technology increases, it will doubtless require a significant understanding of field of view.

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