Sunday, January 31, 2010

Startle Reflex

How many times have you been sitting there minding your own business when some sound brings you up out of your chair? Or maybe some quick movement past you stops you dead in your tracks. Even a sound such as an explosion or fireworks or a moment in a song could ignite something deep within you. It could be a flash of light or about anything but whatever it is, you stop and try to determine what is going on.

What Is The Startle Reflex / Startle Response
The startle reflex is something everyone knows about. We've all felt it at one time or another. It is the response of our mind and our body from a sudden unexpected stimulus. It could be a sound, a flash of light, some event, a touch or a quick movement around us. There are many ways we are startled.

When started, our bodies go through many physical changes including contraction of muscles of the arm and leg, blinking, increase in blood pressure, respiration and breathing rate. While the muscles contraction responses generally resolve themselves in a matter of seconds, it often takes our breathing, respiration and blood pressure much more time to normalize.

Startle Response and PTSD

If there is an exaggerated startle response, it is called hyperplexia and is often seen in people with PTSD (Post Traumatic Stress Disorder).

Startle Response Video

Here's a great video depicting what happens in a person when a startle response is encountered. The video is about self protection but the beginning of it really shows in a simplistic way, just what the startle response does.

My Startle Reflex Experience
One of the things I am learning through the Evolutionary Healing Institute with Dr. Paul Canali is just how important the "startle reflex" is to the healing of trauma. Through pendulation of the autonomic nervous system, one is able to begin moving through trauma that is stored in the body without becoming overwhelmed and shutting down. The startle reflex is one of the ways used to do this because the startle reflex kicks the system up into sympathetic mode and once dissipation has been allowed to complete, the body can then come back down into a more relaxed or resting mode (parasympathetic). By doing short bursts of stimulation and rest, the person is able to move through much more than if they were just brought into the trauma stimulus full force. Of course, it greatly helps the person going through this to be safely supported by someone that is able to be there in a grounded way without judgment.

One good way to measure the state of the nervous system is by use of a pulse meter. I use the one pictured to the left. There are times that a person feels one way but when you measure the pulse, you can quickly see if the person is in sympathetic or parasympathetic mode. If the pulse is going high and not dropping down, you are still in sympathetic and there is still arousal or stimuli within the body. Until that arousal or stimuli is released, the body will not be able to go completely into parasympathetic mode. This of course may not happen all at once and may take time to go further and further into it. With the pulse meter, there is no guess work as to what is going on in the body. The pulse of the body is real where what one may experience may not be truly what is going on.

Other Sources of Information

1) Wikipedia - Startle Reaction

2) Evolutionary Healing Institute: Autonomic Nervous System

3) US National Library Of Medicine - National Institutes Of Health: Fear Appears Fast

4) How Stuff Works: Startle Response

5) Trauma, Biology And Hyperarousal

6) Hope And Possibility Through Trauma

*For more articles, check out the Mind Body Thoughts Blog


  1. So why are some people so jumpy then? My dad, and even me to some extent, jumps at the littlest thing! (And then proceeds to get mad but that's another story!)

  2. Often the nervous system is revved up to a point where the slightest thing can make you jump. Consider if you were in the jungle being hunted by a tiger and you stepped on a branch that crackled and popped. You would jump and most likely the tiger would jump as well. Our bodies react much in the same way. Even though there is no "known" threat, our bodies are still reacting to something that happened at some point. If you want to read more on this, check out Peter Levine's book - check out the following post on that.

    Anger is just the final part of the startle - it is the nervous system being so revved up, that the energy (reaction) has to go somewhere.