Mirror writing

Mirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror. It is sometimes used as an extremely primitive form of cipher. A common modern usage of mirror writing can be found on the front of ambulances, where the word "AMBULANCE" is often written in very large mirrored text, so that drivers see the word the right way around in their rear-view mirror.

Some people are able to produce handwritten mirrored text, and Leonardo da Vinci wrote most of his personal notes in this way. Mirror writing calligraphy was popular in the Ottoman Empire, where it often carried mystical associations.

Research suggests that the ability to produce handwritten mirror writing is probably inherited and caused by atypical language organization in the brain. It is not known how many people in the population inherit the ability to write mirrored text, but an informal Australian newspaper experiment identified 10 true mirror-writers in a readership of 65,000. Half of the children of people with the ability inherit it. A higher proportion of left-handed people are better mirror writers than right-handed people, perhaps because it is more natural for a left-hander to write backwards. 15% of left-handed people have the language centres in both halves of their brain. The cerebral cortex and motor homunculus are affected by this, causing the person to be able to read and write backwards quite naturally.

In an experiment conducted by the Department of Neurosurgery at Hokkaido University School of Medicine in Sapporo, Japan, Scientists proposed that the origin of mirror writing comes from damage caused through accidental brain damage or neurological diseases, such as an essential tremor, Parkinson’s disease, or spino-cerebellar degeneration. This hypothesis was proposed because these conditions affect a "neural mechanism that controls the higher cerebral function of writing via the thalamus." Another study by the same university discovered that damage was not the only cause. The scientists observed that normal children exhibited signs of mirror writing while learning to write, thus concluding that currently there is no exact method for finding the true origin of mirror writing.

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Wikipedia