7 January 2021 Visual hallucinations in people who have lost their sight can stem from spontaneous activity in the brain’s visual centres, according to a study led by UCL and Weizmann Institute of Science researchers.
The study, published in
Brain, investigated why some people who have lost their eyesight experience vivid hallucinations, a condition called Charles Bonnet syndrome.
The researchers were studying slow, spontaneous fluctuations, which appear unconsciously in our brains when we rest. The research team was seeking to understand whether unprompted behaviours, that occur without any external cause, might be triggered by these spontaneous brain fluctuations.
People experiencing Charles Bonnet visual hallucinations presented the research team with a rare opportunity to investigate their hypothesis. This is because in Charles Bonnet syndrome, the hallucinations appear at random, in a truly unprompted fashion, and the vis