From scary sleep paralysis, to recalling memories that never happened, a new exhibition is exploring the art inspired by human consciousness. Here, we see how artists have interpreted moments from the mind.
Do you dream sweet dreams each night - drifting gently in and out of sleep? Or is the boundary between sleeping and waking a more frightening experience?
It is thought close to 8% of people are prone to experiencing "sleep paralysis" - a condition which can leave sufferers with a temporary inability to move or speak. It is not the same as a bad dream or unsettled sleep.
"You are in a state where you are awake, but your body is paralysed and your breathing is restricted," says Emily Sargent from Wellcome Collection.
"You are aware of your surroundings but are unable to cry out. You may have visual or audible hallucinations. You could feel presence of an imagined malign intruder."
Sleep paralysis is one of a number of conditions on the edge of human consciousness being explored at the Wellcome Collection in London in the exhibition, States of Mind.
"People describe feeling a weight on their chest," says Sargent, "depicted here in monstrous form in this 18th Century drawing by Henry Fuseli."
The woman is also on her back and with her head lower than her body - another hallmark of a sleep paralysis attack.
In some cultures the condition has been enshrined in folklore.
Here, Fudo Myo-o - one of the important deities in Japanese Buddhism - holds a metal chain in his left hand ready to "paralyse" a sleeping enemy.
The next image, of a dissected brain, was drawn by the French philosopher and scientist Rene Descartes.
"We wanted to tease out the voices which have talked about consciousness," says Sargent. "He's known as the father of dualism - the idea that we are made of body stuff and mind stuff - one earthly, the other enduring."
The image shows the grape-shaped pineal gland in the centre, which Descartes believed was the seat of the soul.
"It gives us the principle of a magical ghost in the human machine."
Descartes' thinking - of a separation of body and soul - played well with the world's major religions, including Christianity.
The next image - created for a poem, The Grave by Robert Blair - shows the earthly body of a young man laid out, and his female soul leaving him for heaven.
"I like to think of my memories as a box of old photos which remain true each time I return. But memory doesn't really work like that," says Sargent.
"The brain is doing its best job all the time, but is surprisingly vulnerable to influence."
The exhibition challenges our idea of being able to accurately remember moments from the past - and considers the relative ease of creating false memories.
The next images show a shopping centre - deserted, except for some young children. They were created by artist AR Hopwood, who was inspired by research from American psychologist Elizabeth Loftus.
Loftus and her team demonstrated that you could, through suggestion, persuade about 25% of people that they had been lost in a shopping mall as a child - even though they had not.
Her study in the mid-1990s involved students at University of Washington, and an older relative - often a parent.
The students were asked to recall events from their childhood - details of which were provided by the relatives. But details of one event - getting lost in a shopping mall - were false.
Claire's story is also featured. She has severe amnesia and can't recognise faces.
"The past exists as a space you can't enter or feel, and the future as a space you can't imagine," she writes.
She was left with the condition after developing a serious brain lesion following an infection.
When she left hospital she had to be told who her children were.
To try to combat the effect of her memory loss, Claire wears a device called a SenseCam around her neck - which takes photos throughout her day.
These images were taken on a visit she made to St Kilda, 40 miles (64km) west of North Uist in the Western Isles.
"Claire can look back at the photos at the end of the day," says Sargent, "and they will trigger memories for her which would be otherwise inaccessible."
What could happen to you when you are made unconscious clinically?
Could a mischievous group of tiny blue men jump on you - armed with a hammer, callipers and miniature musical instruments? No.
But what the next image does do is bring to mind a patient's feeling of mistrust when they are under anaesthesia.
"Consciousness under anaesthetic is not like going to sleep, it's more like a coma," says Sargent.
"Patients are assisted with breathing, and there are no sleep-wake cycles."
Even though sometimes, eyes remain open.
But there have been accounts of patients being awake but immobile - in a disordered sense of consciousness - when they were supposedly under anaesthesia.
The images come from a 2005 film by Israeli artist Aya Ben Ron, in which she shows the moments from operating theatres when patients fell unconscious under general anaesthetic.
Between 2009-11, the same artist looked at the treatment of young patients in persistent vegetative states - who received care at the Reut Medical Center in Tel Aviv.
"Patients in a PVS show no response to stimulae, but they do have sleep-wake cycles," says Sargent. "Eyes will open, but they won't track when you shine a light."
She explains how the exhibition looks at the long-term work of British neuroscientist Adrian Owen, who is trying to unlock that world.
"How do you get into the brain of someone who doesn't respond to anything?"
Owen scanned the brains of PVS patients in the UK and Canada - and spoke to them during the procedure.
He asked them to think about two things - walking around their own homes and playing tennis.
In normal circumstances - thoughts of spatial navigation, and moving arms back and forth - would register certain brain activity.
Owen found that 20% of those patients tested were able to respond to his commands - using the two imagined tasks to communicate.
"While there was a response from just a minority of those tested," says Sargent, "in some cases patients were forming new memories."
All images subject to copyright.
States of Mind: Tracing the Edges of Consciousness is at Wellcome Collection, London, until 16 October 2016.