Scientific material on how the eyes behave under stress

[poihths]

I'm hunting for scientific papers in refereed journals that describe how the eyes behave in situations of severe stress, such as trigger an intense fight-or-flight reaction.

My understanding is that any human being, on become aware of a deadly threat, focuses both eyes on the threat with the eyes wide open, and that this reaction is not under conscious control, that it's an autonomous response.

However, I'm finding it difficult to find scientific evidence that this is true - studies that have tested it and found that it does indeed happen that way.

If anybody can post a bibliographic citation pointing to such a paper, I would be very appreciative.

Mind you, I'm not just looking for any publication that says it's so. I'm looking for publication of experimental work that demonstrates it's so.

I'm hunting for this re a writing project I'm involved with.

Many thanks in advance for any pointers!

 

[Loosedhorse]

Autonomous response

Autonomic response. Specifically, the response to adrenaline (epinephrine), which acts on the sympathetic nervous system.

You don't need articles: a basic textbook or even wiki will help you out. Adrenaline has many effects.

In the eyes, the main effects are to raise the lids (open the eyes wider) and open the pupils (lets more light in, but can blur things).

However, the most-talked-about effect of stress on vision is "tunnel vision," meant in this context to describe the loss of peripheral vision and dominance of the central vision. It represents a danger to those being attacked, as it makes them less likely to notice additional threats from the side, and must be compensated for by actively searching for additional threats by moving the eyes and head.

It is not clear why tunnel vision happens (whether it's a brain or an eye phenomenon, for example), and it doesn't happen to everyone. But it happens enough to train to compensate for it, if you train for SD at all.

 

[bikerdoc]

Start with.
Opthamology Journals? Local med schools? National eye organizations?

 

[GEM]

Use google scholar or if at a school with access to academic databases - medline, psychinfo.

 

[Fred Fuller]

Something like this, perhaps?

lpl
===

http://www.wjh.harvard.edu/~cfc/Simons1999.pdf

Gorillas in our midst: sustained inattentional blindness for dynamic events

 

[poihths]

Interesting, but not it

Really interesting article but it doesn't address the key thing I'm looking for - under stress, do people pop both eyes wide open, and if so, is that response controllable?

Re the recommendation to try Google Scholar - I've been trying that, but if the material is out there, I haven't been able to hit the right combination of keywords to bring it up.

Re the person who wrote, "You don't need articles: a basic textbook or even wiki will help you out," OK, I don't need an article per se; a respected textbook would do very well, but first I need to find one, and that's the problem! A wiki will NOT do. I need something that's been through an accepted review process and published as accepted scientific literature. Wikis don't meet that expectation, at least not yet. Perhaps they should, but they haven't achieved that level of acceptance yet.

The closest I've come so for is a Marine Corps training document (USMC CMC-30R 24 Feb 2006) which states that the answer to both my questions is yes, but states that as accepted fact without any supporting references. So it's close, but no teddy bear.

 

[Red Cent]

Tachypsychia

 

[Talin342]

Regarding Wiki

A GOOD wiki article should have foot note references, which should link to the appropriate scholarly articles

 

[Fred Fuller]

How about

http://www.ionpsych.com/2011/01/26/stress-improves-perception-but-at-a-cost/

?

lpl (Have you tried finding a librarian who's still working, and not retired and rusty like I am? 8^)

 

[Odd Job]

Poihths, you can get this sorted out by downloading a trial version of EndNote. It has a nice search engine and will get you what you want in terms of article titles and sometimes detailed abstracts from journals (accessing PubMed, Medline and others).

http://www.endnote.com/endemo.asp

 

[Al Thompson]

Just a quick scan, but there seems to be some things here that may be of interest.

http://www.forcescience.org/articles.html

 

[GEM]

Tachypsychia - neuroscientist out of Baylor says it doesn't exist. Perceptions don't speed up but it is a memory effect of having a particular dense memory during recall.

 

[Double Naught Spy]

Tachypsychia - neuroscientist out of Baylor says it doesn't exist. Perceptions don't speed up but it is a memory effect of having a particular dense memory during recall.

That is a bit existential. It doesn't actually happen, but we only recall the event in that manner. If we only recall the event happening in that manner, then how do we know it didn't actually happen? How can a scientist say that time is not perceived slower during an event? How can the scientist know the rate of perception during the event versus what is believe to have been perceived about the event afterwards?

However, this testing indicates information can be taken in quicker during near-death/high stress experiences.
http://www.youtube.com/watch?v=RjlpamhrId8

Which is contradictory to information Eagleman reported later...
http://www.livescience.com/2117-time-slow-emergencies.html

...though they were his tests.

If you go with the premise that the brain is laying down richer memories with more information in more places, then it would stand that more information is being processed at the time of the event and so time is perceived to slow down. His experiments specifically noted that time estimated by participants were about 1/3 longer than reality.

With that said, the visualization test is problematic. Time may be perceived to slow down and slow down as it happens, but that does not mean that superhuman skills materialize. Time may appear to go slower, a matter of perception, but time does not actually go slower and so a person isn't very likely to be able to see things with a speed or clarity that they could not under non-stress circumstances.

 

[Vern Humphrey]

However, the most-talked-about effect of stress on vision is "tunnel vision," meant in this context to describe the loss of peripheral vision and dominance of the central vision. It represents a danger to those being attacked, as it makes them less likely to notice additional threats from the side, and must be compensated for by actively searching for additional threats by moving the eyes and head.

It is not clear why tunnel vision happens (whether it's a brain or an eye phenomenon, for example), and it doesn't happen to everyone

I think the evidence is clear, tunnel vision (as something that happens under stress) is a brain phenomenon.

After retiring from the Army, I worked for many years for Link, which makes training simulators. In making Naval Flight Simulators, you have to have two aircraft carriers -- one with normal proportions, and one that is much longer and narrower than any carrier ever built. The first carrier is used for most simulation -- but for landing, you have to switch to the second carrier, because that's how pilots see the carrier when landing.

Similarly, when studying combat operations, one thing I found was that poorly-trained units will continue trying to do the same thing, even after it's apparent that is the wrong thing to do. That's a kind of "tunnel vision."

A third kind of "tunnel vision" is the rejection of help -- I found that in units under fire, in police departments I studied, and in fire departments.

 

[Loosedhorse]

I think the evidence is clear, tunnel vision (as something that happens under stress) is a brain phenomenon.

Present the evidence, please. It would be helpful.

There is some evidence that visual gray-out (and visual red out) due to G-forces are both retinal phenomena, but the evidence is still suggestive rather than conclusive. And it is not at all clear that visual gray-out and stress-induced "tunnel vision" have the same physiologic mechanism, but they may.

one that is much longer and narrower than any carrier ever built...because that's how pilots see the carrier when landing.

Also interesting. How do we know that pilots see the carrier that way--by their report? Is it known why they perceive it that way--do the carriers seem thin and long due to the pilots' airspeed, or due to their stress?

(I see an advantage to training pilots on "thin" simulated carriers, just so the real thing seems "easy" by comparison--as if it could seem easy.)

Re the person who wrote, "You don't need articles: a basic textbook or even wiki will help you out," OK, I don't need an article per se; a respected textbook

Walsh and Hoyt's Clinical Neuro-Ophthalmology is THE definitive text for the sympathetic nervous system's effects on the eye and lids. And for a whole lot more. There is a smaller, "basic" volume called "Clinical Neuro-Ophthalmology: The Essentials," which is probably all you'd need.