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Table linked from theysaid discussion in 2004
Mellie's description of origins from theysaid 2/15/08:
Under high stress conditions such as fear, the entire Sympathetic Nervous System (SNS)
is activated, producing a “fight or flight” response: this is an immediate,
widespread physiological arousal response. The fear-related stress hormone -- epinephrine (commonly called adrenalin) -- causes physical, cognitive, behavioral,
performance and heart rate changes. After the danger passes, nor-epinephrine
returns the body to a balance, but because the body has had such a profound
change in response to the adrenalin, a backlash often follows.
Many of you probably know this parasympathetic crash. You've probably
felt it following prolonged stress
arousal during an intense fire season. The parasympathetic system symptoms include profound exhaustion, even nausea, vomiting,
dizziness, and depressed heart rate and blood pressure. Nerd on the Fireline
once wrote about this on Familysaid- about
grumpy firefighters after the season is over. She had a good graphic
too... (Safety Expert Dr. Gordon Graham -- the "Predictable is
Preventable" guy -- spoke on this topic several years ago at the R5
Chiefs meeting.)
The numbers on the table are ballpark heart rate numbers related to the
SNS stress response. There are potentially large individual differences in
heart rate relating to physiological arousal and other cognitive, physical,
performance and behavioral responses to the stress hormone. Let me be clear, I'm not talking about
increased heart rate due to exercise. That's different. Lots of athletes
perform optimally when their heart rates are elevated; with conditioning
and practice they can perform well physically and cognitively and their stress hormones
may not be greatly elevated. However, if they become stressed (fear or
performance fear, demands exceed their ability to cope, etc.) their heart
rate increases and their performance falls off. The inverted u-shaped
arousal :: performance curve was described by Yerkes and Dodson in a very old publication
in the early 1900s, if I recall correctly. (OK, here's a description:
Yerkes-Dodson Law.)
Also note that people can have high heart rate unrelated to SNS stress. Older people
often have higher resting heart rates and may be more reactive to stress and
slower to recover than younger people who are better conditioned.
The topic of stress and fight/flight grabbed my attention in a deep way
in about 1990 in conjunction with Carnegie Mellon University/ U Pittsburgh
post doc program on stress. A bunch of us with different areas of interest
(some were involved in cardiovascular stress research at Pitt,
dang, can't remember the name of great stress and cardio researcher) were
brainstorming correlations between fear-induced stress, different kinds of
functioning -- both macro and micro -- and heart rate. A bit later I read a
lot of Bob Sapolski's work (Why Zebras Don't Get Ulcers; Stanford
University) and Bruce McEwen (The Hostage Brain; Rockefeller University) who
looked at the effects of hormones on brain function/fight or flight/ and
also the HPA stress axis.
They were part of a MacArthur Foundation Working Group on Stress and Health
that I had the good fortune to interact with.
The MILITARY ended up being where the rubber hit the road for this
kind of research, because they had lots of [willing?? (grin)] subjects and
could see some real benefits to studying the psychology of combat [like staying alive
and surviving re-entry into the non-war world]. That's where some
of the cutoff numbers coalesced: with Dr. Dave Grossman's and Bruce Siddle's
research with the military in the mid-90s. Siddle wrote
Sharpening the
Warrior's Edge. Some really good books by Lt Col Grossman are
On Killing and
On Combat, the Psychology and Physiology of Deadly Conflict in War and
in Peace (this last book with Loren Christensen). (On Killing was nominated for
a Pulitzer. Grossman did a lot of lecturing to Police and Military, taught
at West point; I think his lecture I heard, the Bulletproof Mind, turned
into On Combat. He's a very fine lecturer, dynamic like Gordon
Graham.) It's fascinating stuff, Dave lays out a stress related psychomotor physiological aspect of
"human factors"
that influences decision making and performance.
(Whenever soldiers, police or firefighters are criminally charged, I
always pray for a person like Dave Grossman to take their side and put their
actions into perspective. It's not black and white. People simply do not
know how altered human function, physiology, cognitive performance,
reasoning etc are when adrenalin kicks in.)
Bruce, I don't know if Siddle was first to publish or
if Grossman was. They may have done the research together. I don't know which journals their original work is
published in, maybe it was only available to the military, but their work is important and profound. Good luck with
sorting out the table. I wrote it as kind of an off the cuff response to some
question on theysaid. Maybe read On Combat first. Wow, look what I
just found: Grossman has a website:
Killology Research Group His publications are listed there. Mellie |
