February 16, 2009

Re-visiting what happens during life-threatening situations

David Eagleman is guest blogging this week.

One interesting direction of transhumanism lies in the possibility of teasing out latent talents buried within us. In its grandest form, the question becomes: what are the possibilities for unearthing some sort of “superpowers”? The detection of exceptional abilities would not only (potentially) improve the human condition, but also give us stunning new data to draw from for our biological theories.

The search for hidden powers is by no means new, of course. Artists have long used drugs to enhance creativity, and students around the globe are pounding energy drinks to optimize their cognitive abilities.

But my interest, in particular, is in time perception, and so my next three posts will be about issues I’m chewing on in that domain. As George covered earlier, a few years ago I set out to address our capacity to perceive the world in slow motion. We have all experienced (or heard described) that time seems to “slow down” during a car accident, or during other high-adrenaline situations. So my laboratory performed experiments to directly address this, and, to my slight disappointment, we could find no evidence that people could really see in slow motion. Instead, they all seemed to believe that a scary event lasted longer—but only when they were reconstructing the event retrospectively. This suggested that the duration expansion during fear was a trick of memory. During a frightening event the emergency control centers in your brain quickly come online and lay down memories on a secondary memory track. Under normal circumstances, your memory is quite leaky; in frightening situations, memories tend to stick better. The end result is that we are not actually able to see in slow motion like Neo in The Matrix, but instead that consciousness seems to be postdictive, that is, constructed in retrospect. So much for the seeing-in-bullet-time superpower. Bummer.

However, since the publication of that study, I have received dozens of emails from people describing their life-threatening experiences. Despite our negative results in the slow-mo domain, there are clearly interesting things going on in the moment of an accident. I’ve noticed a few patterns. First, it seems that the duration dilation is reported only when someone sees the event approaching, as in sliding on the ice toward a truck. When a person is blindsided, there seems to be something like a loss of time: everything is over before you know what happened. So the duration dilation seems to require anticipation. This is consistent with the need for the emergency control centers to kick into gear.

The second thread in virtually all the descriptions is a total calmness about the life-threatening event as it takes place. As a historical example, in 1843, the African explorer David Livingstone was sprung upon by a lion. The lion shook Livingstone in his jaws the way a dog shakes prey. When someone else raised a rifle, the lion dropped Livingstone and went after him instead. As a result of the event, Livingstone lost power in his left arm for the rest of his life. But the extraordinary thing was that Livingstone reported that he had felt “no sense of pain nor feeling of terror, though quite conscious of what was happening.” Similarly, it is commonplace for a soldier to not notice wounds, even mortal wounds, until after the battle is over. This appears to be the result of what’s known as “stress-induced analgesia.” All the body’s resources are marshaled for fighting (or running) one’s way out of a situation, not for tending to wounds. This analgesia depends on the release of chemicals in the brain called endorphins. So that’s good news for humans who end up in bad situations. As Livingstone interpreted it, it is “a merciful provision by our benevolent Creator for lessening the pain of death.”

What’s a bit stranger, and unaddressed in the literature, is that this calmness is often accompanied by a bizarreness of thought. For example, one man reported that while he was sliding along the asphalt after being thrown from his motorcycle, he composed a little song to the tune of his helmeted head bouncing against the asphalt. No fear, no panic, just a calm little tune. And I experienced something similar when I was younger and fell from a roof. As I plummeted toward what was likely to be my death, I was calmly thinking how similar the fall was to Alice’s fall down the rabbit hole in Alice in Wonderland. No fear, no panic, just a crystal clear thought about a moment from a children’s book.

The final commonality is that people claim to have made very good decisions, especially as regards motor actions—as in “I decided to jump onto the approaching car hood,” or “I darted out of the way with no hesitation.” Of course, there is no way to assess the subjective impressions of those who made the wrong decisions, because they can’t tell us; this leaves open the possibility that the survivors who write to me are those who enjoyed a bit of luck, and their brains retrospectively construct a good story about the potency of their decision-making.

At this stage, there’s one more thing I want to look into, if I can figure out a way to do it scientifically. I’d like to better understand the common claim that “my life flashed before my eyes.” Does this really happen? It is difficult to know, at first blush, whether the statement is metaphorical. At least in some cases, the statement becomes something people say when they are trying to be clear that an event was extremely frightening. It becomes a linguistic equivalent of “that was really scary”, in the same way that saying “I was on cloud nine” is not meant to really imply something about levitation or cumulonimbi. The question is whether it is being used metaphorically in some cases, or in all cases. Take this example from another motorcycle accident victim:
…it was at this stage that I started to think of some of the people I had gone to school with in both Primary and Secondary School. I thought of the names of teachers and students that I hadn’t thought of or remembered in years and could see their faces and the school yards as vividly as if it were only a few days ago. I could hear their voices in my head and was saying their names out loud.
The challenge for brain researchers is to understand whether there is a nugget of something real at the heart of these claims, something that would force a change of our views about the capacity of memory, the potential speed of running through recall, and the power of calcified memories to suddenly shoot up to consciousness. Not surprisingly, these questions have not been addressed because of the difficulty in setting up a safe and meaningful experiment. Are there any ideas about what’s happening in these situations, or how to address these in an experiment? I’ll be very interested to hear readers post their own experiences or hypotheses.

In my next two posts I’ll address some different aspects of slow motion and the speed of perception…

David Eagleman is a neuroscientist and a writer. His book of literary fiction, Sum, debuted internationally this month.

16 comments:

Anonymous said...

I think there might be some hidden superpowers in the way the conscious mind can access visual information. When people close their eyes they can't see real images, like people pictures as vividly as when the image is in their front, although i believe this could be possible. When i was smoking marijuana back in the days, i could sometimes close my eyes and see real images as if they were open.

Eric said...

Hi - interesting stuff. Hopefully you will consider this idea, even though it isn't very compatible with the neuroscience perspective. I am a pretty advanced meditator who has achieved some of the lower levels of fruition, i.e. experiential knowledge of the end of the illusion of the separate self. Basically, when one investigates very carefully, one discovers that consciousness isn't centered in the mind or body. So, during these highly stressful events, our awareness can become primary over the usual confusion of mind/body. It certainly has many of the super-calm, detached, and highly aware aspects that near-death (that you see coming) often does.

Machine.Elves said...

Hi David,

Fascinating article. In regards to the memory recall, the literature on 'Near-Death Experiences' seems to show fairly conclusively that it is not meant metaphorically in at least some cases. It seems to be a common facet of the shock of imminent death. To go with it is the interesting facet of 'reliving' of a number of these memories in 3D panorama - somehow in a split second - and being 'shown' how certain actions impacted upon others.

The calmness in the face of death also shows up as a regular part of the overall phenomenology of the NDE - see the work of Swiss geologist Albert Heim (from more than a century ago) on the experiences of falling climbers.

Thanks for the interesting thoughts!

Matthew said...

I always thought notion of your life passing in front of your eyes was just a metaphor. But when I read your description of the motorcyclist recalling his school days, I thought maybe there is some kind of emergency response in action. There is no time for normal association of the imminent danger with a particular memory or course of action. So instead a whole rash of memories are induced. It is like throwing the filing system on the floor in the hope of seeing an appropriate course of action, and not sorting through everything labeled emergency.

Anonymous said...

My sister was driving the Pacific Highway (Australia) with me as the only passenger, and we came off the road. Luckily for us there was a very wide grassy strip between us and the oncoming traffic on the other side. We went into a big slide, and I remember feeling calm and almost relaxed as I said to her, "Go slow" meaning not to slam on the brakes in case we went into a spin. Then we were sliding across this big paddock of a median strip (it was a bit wet, too, so very slippery). It seemed to take forever to stop, and we eventually bumped into the guard fence on the opposite side.

It probably took a long time to stop because the grass was so slippery and maybe she took my advice a bit too much, breaking very gradually, but it felt like a sensation of 'timelessness' - not like a high-speed, adrenaline-fueled, near-death experience. We could have hit a tree, spun back into traffic, gone through the guard rail into oncoming traffic (many semi-trailers driving that highway) but all I remember feeling was detached calm - and afterward my sister said she'd noticed that in my voice. It was only after we got out of the car and looked back at the long skidding trail behind us (and the damage to the car) that we started to feel angry and upset (and incredibly relieved). It was such a calm experience, even though fully aware during it that we could have any kind of impact, including fatal, and that it could happen at any moment. Maybe it helps to try and remember not to panic in an accident situation, but I'm not sure if that was due to my conscious effort or some 'other' part of my brain. Very surreal, anyway.

Zarthon said...

"We have all experienced (or heard described) that time seems to “slow down” during a car accident, or during other high-adrenaline situations. So my laboratory performed experiments to directly address this..."

the experiment involved "The Suspended Catch Air Device (SCAD) diving tower at the Zero Gravity amusement park."

i'm sorry, but this experiment doesn't prove anything. the subjects knew they were going to fall, knew they were going to land safely... etc. and so wasn't really any kind of "life-threatening" situation.

to test what really happens in a life-threatening situation, anything short of actually threatening some one's life doesn't cut it.

i would suggest this is just about impossible to test in any sort of ethical context.

Anonymous said...

Is “my life flashed before my eyes" an idiom, or does it exist in other languages? If it's an idiom, more metaphor, I would think. If it transcends English language and culture, there may be some truth to it.

Anonymous said...

another thought to ponder much like the meditation guy touched on is that our cognitive sense is much slower in everyday events just so it can process much more. In the case of life threatening events you shed the burden of other thought processes which can "free" up your cognitive senses. This can make it seem as if you are thinking faster than your senses are inputting data.

Anonymous said...

cansudiwhat is origin of expression "My life flashed before my eyes." Earlist use recorded?

junking said...

Isn't this the body's endorphins kicking in, as a natural protection in a precarious situation?

People who deliberately cut themselves as a habit are after this stress-relieving out-of-it effect.

Edward said...

Funny, I've been in a few motorcycle crashes...the first one was low-speed cornering; I ended up somehow dropping the bike and standing up on my two feet. Another notable one was cornering at a typical speed, where I was wondering if I should stop or go, decided to go, and ended up going asphalt surfing.

marshallbarnes said...

I want everyone to know that if you feel that David Eagleman is wrong about duration dilation, then here's your proof -
http://www.speakersite.com/profiles/blogs/david-eagleman-phd-baylor

I did a study of his experiment and its history, and it is one of the worse examples of bad science on record. Since he appeared earlier this month on Coast To Coast AM and was talking about it, I felt that I needed to come forward and be a bit more forceful in reporting my findings. Now that I see that he admits here that people were emailing him saying he was wrong - and he still insists his experiment was correct, I am convinced that just how flawed his thinking, methodology and experimental results are, needs to be exposed so that this farce can stop being promoted to the scientific community and the public.

Trevt said...

I remember many times having a 'slow motion' moment while playing sports. I played runningback in football, and on a lot of occasions, I had those moments where everything seemed to go in slow motion. Oddly enough, it was almost always when I made a really good play. I had several teammates and friends who played sports that described similar situations. I used to say that when things slow down like that is when you're having a good game, and when things happen too fast, you're not having a good game. There definitely seemed to be a heightened sense of awareness during those slow motion moments that weren't just an anomaly of your memory remembering the event in slow motion.

Big Dixter said...

I'm interested in the loss of cognitive ability during a life threatening situation. I paraglide and number of accidents that have been investigated are characterised by a significant delay before flight correction or deployment of the reserve parachute. Often the correction required is simple and well within the capability of the pilot but their responses appear to slow down. I had assumed this was just panic. Any other ideas?

anon said...

I would argue that these perceptions that have been noted are only "forensic reconstructions" of the mind, after the fact; similar to how we have the idea of "secondary elaboration" when recalling a dream. This makes the matter nearly non-researchable in any purely scientific sense.

The biological "Fight or Flight" effects of pure adrenaline dumped into the bloodstream could probably provide insight.
However, it would be completely unethical to literally inject someone with these glandular chemicals just to study their psychological "recollection" of having epinephrine in their body.
It would be nearly equivalent to a near-death experience in a biological sense, however; but would be so uncomfortable to a "test subject" that whomever tried to administer the experiment would belong behind bars.

It is, therefore, and insoluable problem, and we can only rely on forensic interview of involuntary "test subjects" in order to ever prove or disprove any theory on the matter.

gardenman13 said...

Recently, Mr. Welsh (of Weezer) somehow perceived [then commented upon] and then self-co-ordinated the time-line/tapestry of his own death. His prediction supposedly emanated from within a dream sequence, as opposed to the above-referenced article which references sudden, escaped-death scenarios. Other than that: I venture that he Tweeted what he did- and then simply followed through with a suicide/murder or a faked suicide gone wrong -to amuse and astound. That's just a possibility.

Yet preferentially, the way I view "the world"/"time" is from a post-dictive referential point. (And this would explain how Mr. Welsh could have dreamed his end). That is precisely how I seem adept at "reading people" and their (re-)actions (which has been noted and discussed before). That is, this means that what we believe as 'time' 'moving' 'forwards' is illusory, and that it is actually something like quite just the opposite- but not quite; and, conjointedly, we have full access to awareness of the ending [or, all the 'moments of direction'] since time is being created from backwards to forwards, from end to beginning, and thusly post-dictively. It is almost as if we are seeing [or reading or feeling or believing] a mirror in the fourth dimension. So, it is only when events occur ("life flashing before my eyes") that jar us out of normalcy, which then afford us to be witness to so-called 'predictive' moments. If we really knew everything and saw it, it wouldn't be any fun, would it? And it would drive you absolutely insane.