The aptly-named Alice in Wonderland syndrome is a weird condition that distorts your perception of yourself and the world around you. It takes its name from the Lewis Carroll character because, like Alice in the story, people with the syndrome often misperceive themselves as very tiny or our surroundings as hugely oversized. It can also impact the perception of time, making it seem that people are moving in slow motion, and include other visual and aural hallucinations such as seeing people's faces changing into monsters or hearing speech as unnaturally fast. From BBC Future:
Gillian Harris, from Pulborough, West Sussex, in England, was only diagnosed with Alice in Wonderland Syndrome six years ago at the age of 48, despite suffering with it from a young age. "As a child, at times, I felt as if things were further away from me and when I was a teenager, I also became aware my limbs were huge, with my arms being absolutely massive," she says. From the age of about 16, she was diagnosed and treated for epilepsy[…]
In children, encephalitis caused mostly by Epstein-Barr virus is the most common cause of Alice in Wonderland syndrome, whilst it is most often associated with migraines among adults.
Brain imaging is also offering some insights too. These suggest that Alice in Wonderland syndrome may be caused by a dysfunction of a region of the brain called the temporo-parietal-occipital junction, where visual and spatial information are combined with signals about touch, body position and pain. Changes in this key meeting point of sensory information caused by lesions, neurological damage or swelling may alter how the brain interprets the signals.
