Hallucinations – often associated with psychotic disorders – may result from a natural process used by the brain to make sense of the world – say scientists.
Visions and sounds that do not exist can be generated by the brain’s habit of predicting what it expects to experience – filling in missing gaps in reality – the research shows.
It is this ability that allows you to recognise a fast-moving black shape in your living room as the cat even though it was little more than a blur.
Professor Paul Fletcher from the Department of Psychiatry at Cambridge University said: ‘Having a predictive brain makes us efficient and adept at creating a coherent picture of an ambiguous and complex world.
But it also means we are not very far away from perceiving things that aren’t actually there – which is the definition of a hallucination’.