Fear Paralysis Reflex: An important consideration for sensory processing and emotional regulation Blog #10

I have always been jumpy to loud noises and have even been startled by the movement of my own shadow in my peripheral vision.

I remember gasping, jumping and the feeling of tingling in my fingertips. This could be triggered by seeing the shadow of my own car as it moved slowly. 

I asked my mentor at the time to teach me about the fear paralysis reflex. After the gentle testing technique she said that my reflex expression was very active. 

Recall from our initial blog on reflexes that reflexes are like the software code in your cellphone. It gets updated as you get older but if you are running on software 1.0 that has not been updated or is over-active then you might start responding abnormally to sensory input. 

For me that meant that instead of an appropriate adult startle reflex (blinking and slight muscle contraction) I had a big “jump out of your pants” reaction to small sounds or visual stimulus even if that stimulus was my own shadow. 

Many adults and kids can have the fear paralysis taking over in response to touch as well.

These children would cry at the sight of a toy that made sounds. The “Elefun” game was one of those toys (arguably that loud elephant blowing “butterflies” into the air was unusual and terrifying). 

I have also noticed that this reflex is often overly active with the kids that I see that have a tendency to lash out at others physically. 

This can come unexpectedly and from the kids who otherwise wouldn’t hurt a fly. 

See the blog on touch processing for more on why touch can be perceived as pain. 

A few signs that the Fear Paralysis Reflex is not integrated or working well are:

• overwhelming fears/ anxiety
• difficulty managing stressful situations
• avoidant behaviors
• dissociation (feeling disconnected from self)
• insomnia 
• fatigue (1)

The reflex serves to protect us by “freezing our bodies” and, “inhibiting movements.” This Reflex turns into the Startle Reflex in adults (1)(8).

The Startle Reflex is a protective response that includes a muscle contraction through head trunk and legs.

The startle reflex or response is thought to be a combination of reflexes, one of which is the acoustic startle reflex which occurs with sounds over 80 decibels (10). 

The response can be measured using the contraction of the muscles that cause blinking in response to auditory stimulation. 

One research article found a significant correlation between increased anxiety the intensity of the adult startle response (acoustic startle response) in 111 young women (4). 

These women completed the State-Trait Anxiety Inventory (STAI) and were exposed to noises with their eye blink measured by an EMG on the orbiculares oculi muscle of each eye.(4). 

The women that had the largest movement in eye blink also reported the largest anxiety scores.   (This was more significantly observed in the left eye more than the right interestingly)(4).

Another study measuring the startle response from 60 civilians found that people’s increased reports of physical or sexual abuse were significantly correlated to increased startle on compared to those with low abuse (p<.01) (5).

Several sources cite the hormones connected to the hypothalamic-pituitary-axis (HPA) and the amygdala as modulating this reflex (4)(5)(8).

An increased startle response is a symptom included as a cardinal sign in the DSM V (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) for PTSD. Several studies have found that the blink response to sound is significantly greater in veterans than civilians (6). 

One study found that the increased startle was only associated with PTSD and not the history of corporal punishment or current intimate partner aggression in 52 women (7).

This area continues to be researched and it will be interesting to see what comes out of further studies on the topic. 

I would argue that these increased startle responses are tied to the integration of the Fear Paralysis Reflex. 

Fear Paralysis and Moro Reflex

There is some debate as to the connection of the Fear Paralysis reflex to the Moro Reflex. 

One differentiation is that the Moro reflex is “dynamic” and paired with movement of the body. It is stimulated by vestibular input (8). 

Another differentiation of the Moro and Fear Paralysis Reflex is the position of the arms in abduction and external rotation in the Moro reflex (8).

Comparatively, the fear paralysis reflex is about inhibiting movement in response to auditory, visual or tactile input (1).

For some people maybe the Fear Paralysis Reflex never got integrated. Even if it did, physical traumas and emotional traumas can change the responsiveness of a reflex. 

I imagine this behavior of reflexes acting like a body guard that was sleeping in the background awakened and easily put into over-drive. This happens when someone experiences stress, physical harm or a traumatic event.  

Trauma is an “unbearable” or “intolerable” event according to Bessel Van Der Kolk author of the seminal book The Body Keeps The Score: Brain, mind, and body in the healing of trauma.

What defines a traumatic event is highly individual to the person experiencing the event.

So for children or anyone it may be something very personal and possibly even imperceivable as trauma to anyone other than the person experiencing the event.

Physiological quality of the Fear Paralysis Reflex:

The Fear Paralysis Reflex can also affect posture as the body may prepare to withdraw to protect itself. Abdominal muscles contract, limbs abduct, and the person may hold their breath. There may also be fluttering eye lids and blinking and an audible gasp (1)(8).

 This reflex can also help mitigate pain and discomfort and should disappear when the triggering stimulus is removed. 

When this reflex is not working well (unintegrated) children have an especially hard time focusing.  The slightest inputs from the environment can set them off. 

These kids may seem to be the ones that are trying to control the environment and can be the noise police (despite being loud themselves). 

They may be completely distracted by the sound of a telephone ring or an alert from your phone. 

For kids I see, working on this reflex is one important piece of the emotional regulation puzzle. 

As part of a comprehensive plan the ones that were lashing out are now handling their emotions and no longer hurting themselves or others. It is also helping with the kids I see with anxiety as well. These kids are having fewer episodes of paralyzing fear and meltdowns are decreasing from daily to weekly. 

Finally, I find that reflex integration activities are assisting with the processing of touch input both personally and for my clients. 

Personally since this last year I realize that I have not felt needlessly scared or startled. 

Considerations for working with people with unintegrated Fear Paralysis Reflex:

1. Do not deliberately scare them and make sure family members don’t use scaring someone as play- this response is described as highly uncomfortable.
2. Do not deliberately tickle them- This can be very uncomfortable and arguably traumatic for people with tactile sensitivity.
3. Approach children who may be anxious to visual stimulation from the front.
4. Default to using slow firm or heavy pressure touch at first and ask how it feels (some people like light pressure touch but it is good to ask!) 
5. Don’t overwhelm someone. When someone is having a negative experience of shock or fear give them space and time. Decrease the sensory inputs and demands until you know they are feeling good again. 
6. When you have developed a better understanding and relationship with a client you can play with using sound, touch and visual input in a way that is safe for them starting with having them be in charge of changing the sensory input. E.g. encouraging them to play with progressively louder toys or less familiar toys for example. 

I will be posting a free handout on one mindset and emotional regulation activity I use in conjunction to fear paralysis integration so make sure you subscribe to our resource updates below.

And always, it's best to get medical professional evaluation and advice before applying any techniques to children or yourself. 

Thanks for the read! See you in our next post. 

Jasmine the OT

References:

1)Shackleford P, Roy V, Ortego L, Marks T, et al. (2017) Flood Trauma Survival and Recovery Using MNRI Reflex Neuro-Integration Therapy – Scientific Figure on Research Gate. Available from: https://www.researchgate.net/figure/Fear-paralysis-reflex_fig3_322068235 

2)Sherin JE1, Nemeroff CB (2011) Post-traumatic stress disorder: the neurobiological impact of psychological trauma. Dialogues Clin Neurosci 13: 263-278. 

3) Van Der Kolk, B. A. (2014). The body keeps the score: Brain, mind, and body in the healing of trauma. Viking.

4) Poli E and Angrilli A (2015) Greater general startle reflex is associated with greater anxiety levels: a correlational study on 111 young women. Front. Behav. Neurosci. 9:10. doi: 10.3389/fnbeh.2015.00010
https://www.frontiersin.org/articles/10.3389/fnbeh.2015.00010/full

5) Jovanovic, T., Blanding, N. Q., Norrholm, S. D., Duncan, E., Bradley, B., & Ressler, K. J. (2009). Childhood abuse is associated with increased startle reactivity in adulthood. Depression and anxiety, 26(11), 1018–1026. https://doi.org/10.1002/da.20599
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2852033/

6)Morgan, C. A., 3rd, Grillon, C., Southwick, S. M., Davis, M., & Charney, D. S. (1996). Exaggerated acoustic startle reflex in Gulf War veterans with posttraumatic stress disorder. The American journal of psychiatry, 153(1), 64–68. https://doi.org/10.1176/ajp.153.1.64
https://www.researchgate.net/publication/14659100_Exaggerated_acoustic_startle_in_Desert_Storm_Veterans_with_post_traumatic_stress_disorder

7)Medina, A. M., Mejia, V. Y., Schell, A. M., Dawson, M. E., & Margolin, G. (2001). Startle reactivity and PTSD symptoms in a community sample of women. Psychiatry research, 101(2), 157–169. https://doi.org/10.1016/s0165-1781(01)00221-9

8) Masgutova S. (2015). Reflex Integration for Post-Trauma Survival and Recovery. Svetlana Masgutova Educational Institute® for Neuro-Sensory-Motor and Reflex Integration, SMEI (USA)
http://masgutovamethod.com/_uploads/_media_uploads/_source/Scientific-Research-Behind-MNRI-02.18.15.pdf

9)Fletcher, Mary Ann (1998). Physical Diagnosis in Neonatology. p. 472. ISBN 978-0397513864.

10) Rammirez-Moreno, David. “A computational model for the modulation of the prepulse inhibition of the acoustic startle reflex”. Biological Cybernetics, 2012, p. 169