Thanks to the signals from our assorted senses, which combine with our past life experiences, each of us perceives the world differently to one another. We all exist in our own unique reality. “Perception is not a passive process of merely seeing, hearing, feeling, tasting or smelling,” says Moheb Costandi, a London-based neuroscientist and writer who discusses Alice in Wonderland syndrome in his book Body Am I. “It is an active process. The brain acts upon incoming sensory stimuli, based on our past experiences and biases. The way we perceive things influences how we act, and how we act influences what we perceive.”
But, at times our perception can become disordered, such as when people suffer from hallucinations, illusions or distortions. When the perception of ourselves and the world we live in is distorted, we risk losing our sense of self and suffer from depersonalisation. We might even end up experiencing the world itself as being unreal, a process known as derealisation.
In the past, Alice in Wonderland syndrome has been commonly dismissed as a largely harmless condition that doesn’t require medical intervention. Some degree of symptoms are reported in the general population, with up to 30% of adolescents reporting mild or transient experiences of the syndrome. Certain cough medicines and illicit hallucinogenic substances are also known to trigger it.
Sometimes, however, changes in our perception of the world are triggered by something else underlying them. A wide range of causes have been suggested for Alice in Wonderland syndrome in both children and adults, including strokes, brain tumours, aneurysms, viral infections, epilepsy, migraines, eye diseases and psychiatric disorders such as depression and schizophrenia. It has also been associated with some infections such as Lyme disease, H1N1 influenza and Coxsackievirus B1. One study even identified it as a manifestation of Creutzfeldt-Jacob Disease (CJD), a fast-developing and often fatal neurodegenerative disorder.
Jan Dirk Blom, a professor of clinical psychopathology at Leiden University in the Netherlands, who is one of the few researchers who has dedicated himself to studying Alice in Wonderland syndrome, emphasises the need for doctors to take patients describing these symptoms seriously.
Blom says that diagnosis and recognition of Alice in Wonderland syndrome has barely improved over the past few decades. “That is a real challenge,” he says. This often means it can be missed in patients for years.