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What causes sleep paralysis? © Getty Images

What causes sleep paralysis?

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Asked by: Mary Smith, London


During rapid eye movement (REM) sleep, our body is paralysed to stop us from acting out our dreams. When sleep paralysis occurs, features of REM sleep are continuing into our waking lives. In particular we are unable to move and sometimes experience hallucinations.

Both genetic and environmental factors are at play. Circadian genes might be important, although more research is needed to specify which genes are involved. As for environmental influences, it appears that anything that might disrupt our sleep – including stressful life events and alcohol use – can be a risk for sleep paralysis.


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Alice is a Professor of Psychology at Goldsmiths. She has contributed to several diverse research areas, including the longitudinal associations between sleep and psychopathology, behavioural genetics, sleep paralysis and exploding head syndrome. In addition to her scientific contributions she also excels in the public engagement of science. She has published two popular science book (Nodding Off, Bloomsbury, 2018 and Sleepy Pebble, Nobrow, 2019). She regularly contributes articles to the media and has had her work published in outlets including the Guardian, GQ UK, Sud Ouest, Slate Fr, Independent.


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