Is PTSD a Survival Mechanism in Overdrive?

Disturbing experiences don't actually heighten our perceptions. In fact, according to new Weizmann research, in adverse conditions we're more likely to experience slightly different sights or sounds as being the same. The scientists think that this lumping together of similar sensory stimuli may be behind post-traumatic stress syndrome. The experiments showed that volunteers learning to distinguish between similar tones had much more trouble telling them apart when these were associated with a shockingly bad smell. Dr. Rony Paz explains that this blurring of our perceptions may have helped our long-ago ancestors to survive in the real jungle, when instinctively running away at any sound that even remotely resembled the rustle of a top predator may have made sense. But in our modern sensory jungle, that same tendency could make any loud noise evoke the same gut reaction as gunfire, or any building seem ready to fly apart in a fresh disaster.


image: Schuyler Shepherd, wikimedia commons

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I'm sorry, I must have missed the punchline. It seems to me that you were implying that PTSD was brought about by loud noises? Me thinks that the pansy in you needs to experience some real stress in order to truly evaluate PTSD. Come at me with some volume induced stress disorder and you're likely to end up with a five finger imprint on the right side of your cheek (from my perspective, I don't expect you to be some religious turn the other cheek nutcase).

The study shows that during a bad experience, our senses become less sharp -- that is, stimuli that we can normally differentiate become identical to us when we're in an adverse situation. The implication is that this tendency might contribute to PSTD. So the loud noises are just a trigger -- not a cause.

You absolutely DID miss the punchline, Jonesy. But good job spazzing out anyways.

I have PTSD, I'm on disability as a result of that (and a few other problems)

My experience is not that my perceptions are blurred so much as that they become selective. Think of a sort of tunnel vision - the center, what you focus on, becomes extremely sharp, sharper than normal, while the surrounding areas become fuzzed out.

Not that this is a visual phenomenon, I'm just trying to construct a metaphor. For example, I can be standing in line at a fast food joint and while everyone else is concentrating on what they're going to order, my attention is suddenly on two people outside across the parking lot in a tense discussion that looks like it's about to turn into a fistfight. Everyone else around me is oblivious.

As for sound, I tend to sleep in the day and be awake at night because daytime is just too stressful for me, too active, too many sounds. Part of that is likely due to partial hearing loss which leaves me unable to identify and locate the source of sounds, which makes it impossible for me to "ignore" sounds other people hear until I consciously identify the source. One good ear and one bad means I can't tell what direction sound comes from.

Could the "senses becoming less sharp" thing be a form of dissociation? My memories of the many traumatic events I experienced are not normal memories. Most is lost while I was "away," and the full memory is replaced in a sense by a single snapshot feeling and image.


Jones, you ought to become a licensed therapist.

"Mental problems? Let me give you some real problems. With /violence/."

Jafafa Hots, thank you for sharing your experience with us. I hope you find healing with time.

I've been in several life threatening situations (eg: high speed car crashes). On every occasion, time has appeared to slow down to a crawl, kinda like Neo dodging bullets in the Matrix. I know I'm not the only one this happens to and the conventional wisdom is that it happens because your brain goes into overdrive trying to process the situation. I've never heard of anyone experiencing that kind of "time dialation" due to a bad smell.

In other words does a bad smell really induce the stress response of a life threatening situation, or is it just a powerfull sensory distraction?

An acquaintance saw the word 'cullud' in a poem from 1898 and conflated this dated slang with memories of being segregated 70 years ago in New Orleans because of skin color. This might support the Weizmann hypothesis.

By simpleton (not verified) on 16 May 2011 #permalink

Dr. Rony Paz explains that this blurring of our perceptions may have helped our long-ago ancestors to survive in the real jungle, when instinctively running away at any sound that even remotely resembled the rustle of a top predator may have made sense.

Fascinating. I too suffer from PTSD and find that in situations that bring it on (they are spectific), I am frozen by fear and my senses blur in what feels like an effort to pick out the threat from amoungst myriad signals. Its as if my entire sensory being merges and radiates to cover my current world in a grid of hyper-sensitive radar, alert to every nuanced particle of information. I think each PTSD sufferer unconsciously scans his/her world for the threat they are sensitized to: if it's loud noises, then loud noises will set it off; if it's a certain movement, then that movement will set it off. These triggers are unconscious survival programs that alert our otherwise preoccupied minds to danger. Unfortunately for those of us who suffer, our systems have become so finely programmed, usually by repeated antagonisms, that they react often and loudly. Where that we could heal ourselves.

I think that our distant ancestors had intense but brief encounters with danger: their brain/body reacted by producing chemicals just as ours do, but the crucial difference is that the altered state didn't last. Danger over, the body returned to "normal." Otherwise, they would have been in constant non-functioning states; not good for survival. Can we really imagine our ancestors all trying to cope with PTSD? Modern people endure different types of stress, much of it self-inflicted; we go over and over our experiences verbally; we keep our bodies in agitated and uncomfortable states. We cultivate stress. I am in no way saying that PTSD does not exist; I think it not only arises due to initial trauma, but is created by societal behavior (sending individuals off to kill strangers in horrific wars, expecting them to behave in ways utterly contrary to their values) and then by denial when soldiers come home - people just don't want to confront what they've done to their sons, daughters and neighbors by sending them off to endure war. The occasional stress of encountering danger in the environment, such as our ancestors encountered, in no way compares to protracted wars that expose humans to chronic stress and brutal conditions.

Thanks for playing. By the way, "peer review" on the internet means people making fun of you for not being able to follow the last set of valid criticisms levied in the attempt to refute them.