By Tom Geoghegan
BBC News Magazine
What's it like waking up after 10 years "asleep"? After a New York fireman who barely said a word for a decade began talking profusely, what are the experiences of people who wake up from comas and vegetative states after long periods?
"I want to talk to my wife," was Donald Herbert's first sentence in a decade.
The 43-year-old then began speaking at length to loved ones, who feared he would never recover after a roof collapsed on him in 1995. He was initially in a coma, then he regained consciousness, but his speech was slurred and his vision unclear, with no memory of relatives.
Another American, Terry Wallis, who came round in 2003 after a 19-year coma, still thinks it is 1984 and has severe memory problems.
There is a fascination with this deep state of unconscious, a "twilight zone" between life and death and a place few of us ever explore.
Even fewer have lived to tell their stories, but two women in the UK who recovered after weeks in a coma give a rare insight.
WHAT IS A COMA?
It comes from the Greek word "koma", meaning deep sleep
It is a state of deep unconsciousness, in which an individual is unable to respond to external stimuli. The eyes are usually closed and there is no speech.
In a vegetative state, the eyes may open and close and individuals may respond to visual and aural stimuli.
When minimally conscious, patients may track objects, grasp things and respond to words
Julie Bridgewater, 56, from north London, suffered severe head injuries after being hit by a car in 1988. She was in a coma for three-and-a-half weeks and unusually, she does have some recollection of it.
"During that time, something occurred that I had a sense of, it's a sort of lost time-and-space thing," she says. "It's not like I was very aware of what I was doing, as I am now.
"I was looking at myself from a great height, observing myself but not necessarily knowing that was myself or my unconscious or subconscious. I can't define it as conscious intelligence."
Some noises like bleeps on television hospital programmes take her back: "It's burned in my body somehow, hardwired in my body."
Ms Bridgewater also remembers making a choice to live rather than die: what she calls a "contract with myself".
Events going on around her while she was in the coma also registered, like the woman Christine in the bed next to her who, she already knew, had died. And Ms Bridgewater's first words were in Farsi, a language she had learnt many years before, as if her brain was retrieving knowledge long forgotten.
Although her physical recovery has been good, mentally it feels like the Body Snatchers have planted her in someone else's body, she says. And there are more personal changes too.
"On some level, I'm wiser, stronger, harder, but on another level extremely vulnerable and volatile. A grumpy old woman sometimes too.
"I was happy in myself pre-injury, but post-injury, it's like an alien landing on a planet without a map to show your way around. Or seeing the deep sea for the first time."
This feeling of having no purpose or niche still persists, she says. "It's an odd experience and I still feel like that a lot of the time. One tries to be out there, in amongst it all, but there's necessary sanctuary time and disconnectedness as well."
She has suffered from depression, but not to the point of ending it all because of the promise she made to herself to live.
This experience contrasts with that of Sarah Kemp, 26, who was in a coma for six weeks after a horse-riding accident in 1999. At first, doctors said it would be a miracle if she lasted 12 hours and in the following days they gave her parents the option of switching off the life-support machine because they feared the brain damage would be so severe.
Sarah went back on the saddle (pic courtesy of the Kidderminster Shuttle)
"For me it was crystal clear, it was like waking up from a night's sleep, clicking your fingers and being fully there," she says. "I looked at my dad and I knew I couldn't speak so I indicated to him. I don't know how I knew I couldn't speak and I didn't attempt to but I must have heard."
Ms Kemp also had picked up on things around her - she knew what had happened to her, that it was her 21st birthday in two weeks and that her two best friends were coming back from the US in a week.
Four months later, she had made a full recovery after hard work to recover her movement - learning how to eat, drink and speak again - although intense fatigue prevents her working full-time.
Doctors are stunned that even her memory is good despite the fact that, as she puts it, "50% of my brain is just mush". But there was a social gap in her knowledge.
"I had forgotten how to be in the real world. I gave one-word answers to 'How are you?' and it wasn't until I went to the brain injury charity Headway that I learnt how to be me again, socialising and helping people out."
Her chatty personality returned and her appreciation of natural beauty has been enhanced ever since.
Although Ms Kemp's success shows the resilience of the brain and its ability to re-route signals around damaged areas, some injuries can change personalities, says Rebecca Watson of Headway.
"They could become a complete stranger to a friend or partner and can change personality. They could become violent and aggressive or go the other way and become passive."
Some people need prompt cards to help them shop, or help dealing with crowds. Depression is also a problem for the injured and their carers.