Panic - Split from overweight thread

[northen diver]

The onset of panic is very well understood and easily avoided.

The Role of the Amygdala in Fear and Panic

Doug Holt

The definition of fear has proved to be an elusive mystery plaguing scientists. While there is much agreement as to the physiological effects of fear, the neural pathways and connections that bring upon these effects are not well understood. From the evolutionary standpoint, the theory is that fear is a neural circuit that has been designed to keep the organism alive in dangerous situations (1). How does it all work? Learning and responding to stimuli that warn of danger involves neural pathways that send information about the outside world to the amygdala, which in turn, determines the significance of the stimulus and triggers emotional responses like freezing or fleeing as well as changes in the inner workings of the body's organs and glands (1). There are important distinctions to make between emotions and feelings. Feelings are "red herrings", products of the conscious mind, labels given to unconscious emotions (2) whereas emotions are distinct patterns of behaviors of neurons. Emotions can exist of conscious experiencesas well as physiological and neurological reactions and voluntary and involuntary behaviors (3). But the components of fear goes beyond feelings and emotions. It is also the specific memory of the emotion. After a frightful experience, one can remember the logical reasons for the experience (e.g. the time and place) but one will also "feel" the memory, and his body will react as such (i.e. increased heart and respiration rate, sweating). In one recent case, after a near drowining incident, the victim could not only vividly remember each detail, but when doing so, his body reacted as though he were reliving the experience. These feelings of memory are stored in an almond shaped structure in the brain known as the amygdala.

. In the amygdala region alone, there is much controversy surrounding the nuclear subgroups, resulting in classifications that range between 5 and 22 different groups within the amygdala itself. Despite all of this, there are four main groups that have been universally agreed upon. These are the Basolateral, Lateral, Central, and Basomedial nuclei. The amygdala is considered to be the key component to the limbic system, a term that has also been regarded with much recent controversy by researchers in the field of emotions. When selectively electrically stimulated, the amygdala suppresses these behaviors and causes freezing. Freezing is a robust index of learned fear (16).
What is known about the amygdala is that it has a dual sensory input system. Both inputs run from the eyes, ears, and other sense organs to the thalamus. At that point the inputs diverge. One pathway leads directly to the amygdala while the other first passes through the cortex. Each input causes a distinct and specialized behavior. The amygdala is specialized for reacting to stimuli and triggering a physiological response, a process that would be described as the "emotion" of fear (2). After this, the stimuli of the activation of the amygdala is transmitted to the cortex. This is a distinct difference from a conscious feeling of fear. Feelings are thought arise from the second, slower pathway that travels from the sensory input first to the higher cortex and then to the amygdala. Its physiological effects are similar to the initial stages of fear. By having the body ready for action, the second circuit can then take a moment to analyze the signal in its entirety to determine whether or not the threat is real or perceived. If the threat is real, then the body is already on the go, if perceived, than nothing has been lost. But there are problems associated with the double wiring between the higher cortex and the amygdala. Unfortunately the neural connections from the cortex down to the amygdala are less well developed than are connections from the amygdala back up to the cortex. Thus, the amygdala exerts a greater influence on the cortex than vice versa. Once an emotion has been turned on, it is difficult for the cortex to turn it off (2).
Through the usage of fear conditioned rats in laboratory settings, researchers have been able to effectively map out the "fear circuit". The fear circuit is stimulated in rats by means of placing the animals in metal boxes and subjecting them to foot-shocks associated with an auditory signal. This method effectively conditions the rats to fear both the metal boxes in which they had experienced pain and the corresponding auditory signal. After experiencing these stimuli, the rats, when exposed to the auditory signal, react with fear. Occasionally, there can be debilitating problems associated with hyperactivity of the amygdala. Being the storehouse for the memory of fear, it can misinterpret signals from the body and cause inappropriate actions. This can lead to panic. Panic is a heightened stage of anxiety and fear feeding itself in a positive feedback loop and jumping to faulty conclusions, which focus on impending danger, madness, harm, or death. Physically, the body undergoes many changes that ready it for extreme action. There is a marked secretion of glucocorticoids and catecholamines which increases the blood glucose levels. Also, increase production of epinephrine and norepinephrine, which has the effect of vasodilation of blood vessels in skeletal muscles. Other symptoms of the sympatho-adrenergic stimulation involve modifications of breathing, increased temperature, localized sweating, decreased motility of the stomach, bowels, and intestines, constrictions of sphincters in the stomach and intestines, as well as piloerection (20). But the question of what generates panic attacks still remains essentially unanswered at the moment. There are many theories accorded to panic, the most prominent are:
Clark's theory on catastrophic interpretations (1988) sees panic attacks as a result of maladaptive and faulty interpretation of body signals. Beck's theory proposes a similar model, but based on predisposing and precipitating factors. Elhers' theory explains panic attacks as a result of panicogenic interoception. Barlow's theory proposes that panic attacks are modified "fight or flight" mechanisms in the absence of danger (20).
The limbic system, especially the amygdala, has long been considered to be directly implicated in anxiety and fear stages.

Fortunately, there are methods of reducing fear and inhibiting the fear response. Through testing with laboratory animals, it has been determined that when attention is shifted away from the anxiety-provoking stimulus, less fear is observed. When a novel stimulus is presented slightly before or at the same time as a well-trained condition stimulus, the condition response will be disrupted (18). This effect has been described using many methods but the neural mechanism is not well understood at this time. Another method of inhibiting the fear circuit is through conditioning. In a typical conditioned inhibition procedure, conditions are arranged such that one stimulus, denoted A, predicts shock, while another stimulus, denoted X, predicts absence of shock. The result of this procedure is that A comes to elicit a fear reaction when presented alone, but not when it is accompanied by X, the conditioned inhibitor (17). This is a similar method of treatment that is used for people with phobias. This method is inhibiting the emotional response produced by the amygdala during a threatening situation. The patient still remembers that he used to be afflicted by his phobia, but no longer has the emotional response attached to it (3). There is much correlation between the emotional states of fear. Anxiety, distress, and fear are closely related negative emotional states associated with physical or psychological harm. These three emotions can be differentiated by the temporal relationship between the feeling and the potential threat. Anxiety is characterized by the anticipation of being harmed in the future, where as fear is characterized as the anticipation of being harmed in the present. Distress is characterized by the awareness of being harmed at this particular moment. The three emotions can diffuse into one single diffuse state (5).

 

[Storm]

The onset of panic is very well understood and easily avoided.

Ease is a relative thing Walter.

A little anecdote my old days in the army;

I watched recruits my fellow in the diving tower muster up their nerve in the blink if an eye and take the plunge, except for one fellow; he took more than a few minutes to think his way through it. This same recruit, thought absolutlely nothing about hanging his backside over the repelling tower and descending on the rope.

Generally speaking, the recruits on my course overcome their apprehension of the diving tower much easier than the repelling tower (the fact that one has a soft landing and the other usually means broken bones on a hard landing might have something to do with it) but this particular fellow was just the opposite. (Point in fact he hated having his head pushed underwater and he had to overcome that fear beofr he could take the plunge).

My point? Quite simple. When you state imperically what you believe, it stems from your own point of view/experience and from your own anecdotal evidence. What YOU state IS easy stems from the fact that YOU find it easy and the same act may in fact be extremely difficult or impossible for someone else.

In a way I think this is what NetDoc was also alluding to. Not everyone has the mental discipline to control their emotions and think logically through panic situations. While many can develop this control, some just aren't wired that way, and expecting them to suddenly become so because some one wrote a paper on how panic starts, and how to avoid it, is just plain wrong.

 

[Web Monkey]

Go ahead, but it is a crutch.

It also helps reduce the stress level of the boat crew.

Terry

 

[TSandM]

I think it's likely that we all have a point of stress at which we will panic. In fact, it's not too difficult to see panic as an adaptive response, in the sense that, if all the reasonable things you have tried have failed to work, being completely irrational and violent might, in rare circumstances, succeed in saving your life, and therefore be something that was evolutionarily conserved.

But you can push that point further and further away with training. Recognizing the signs of increasing agitation and stress is important. If you don't see it coming, it may be beyond your ability to stifle by the time you even begin to recognize what's happening. Preparing for various scenarios by doing dry runs, or even being taught strategies for handling them, can help reduce the anxiety when something happens. (For example, when, on my third OW dive, I ended up on my back alone in 45 feet of water, my first reaction was, "Oh, buddy separation, I've been taught a protocol for this.") Becoming enured to stress also delays on the onset of panic. We used to say about the second year of surgical residency that, by the end of the year, your panic button had been pushed so many times it didn't work any more. And there was a lot of truth to that. As far as I can tell, training in technical diving has a big component of this.

But if you start out with a little apprehension, add stress (overweighted, perhaps choppy water, unfamiliar gear, strange site) and you don't have any training in recognizing or managing spiralling anxiety, panic can come on fast, and once it's too intense to inhibit, the person is truly out of control, and those people are scary to be around, whether in the water or not.

 

[freediver]

The onset of panic is very well understood and easily avoided.

I would agree to an extent.
When you consider panic, you must first understand that panic rarely occurs instantaneously. First, the person is subjected to various stresses that, if unrecognized, may result in a panic. Accidents are rarely caused by a single factor but are instead the consequence of several factors unrecognized and when they aren't identified, they lower the control of the situation; resulting in panic. So the mechanism is well understood.
The problem with panic being easily avoidable is the fact that the stress that may induce panic is such a personal feature. It will vary from person to person based on the extent of perceived risk. If confronted with a risk greater than a person can manage then the negative stress would likely result in panic.
The neat thing is that nobody is born with stress. It is learned through an educative process! If you take an infant and place them in the water they immediately start to breast stroke and hold their breath for about 40 seconds! This is what they will do until they start to walk. There is no perceived risk. With that being said I think a person can (to a large degree) be taught/trained to recognize perceived stresses and maintain control of the situation before it reaches a stage of panic.

 

[lmorin]

The onset of panic is very well understood and easily avoided.

If you think so, you need to do further reading. See Panic Attacks (Mayo Clinic site). It says, in part,

It can happen anytime, anywhere — when you're alone, with others, at home, in public, even awakening you from a sound sleep. Suddenly, your heart begins to race, your face flushes and you experience shortness of breath. You feel dizzy, nauseated and out of control. Some people even feel like they're dying.

The causes of panic attacks are not known. And, they are more common in women.

 

[The Chairman]

One of the funniest things I have ever seen, is someone trying to reason with a person about their phobia. They try to use reason on an unreasonable fear. I used to be scared of sharks. It took a setermination on my part and plunging myself into the situation in order to defeat it. Logic had very little to do with it.

If the onset of this panic is due to a sudden environmental change, then there may be no time to detect it's onset. This is especially true if we add in any physiological factors.

 

[dumpsterDiver]

My personal observations with regard to panic:

I have experienced a panic response that occured instantaneously and left me COMPLETELY paralyzed. Before this incident, I never really believed that people really can "freeze-up" when presented with a certain stimulus.

My terrifying incident occured when I lived alone and an intruder entered my house and ripped back the shower curtain while I was covered in soap and showering. I happened to see the hand enter the shower and watched as the hand pulled back the curtain. I was so terrified of the unexepected intruder (who I was sure was going to stab me with a large knife) that I completely froze and was too terrified to even look up into the face of my apparent attacker. I just stood there screaming hysterically while my girlfriend (who had driven 50 miles and wanted to surprise me) just kept screaming that "it's only me". I was completely frozen, totally defensless and unable to even look up and fully comprehend the demise that I was irrationally assuming would be occuring in seconds. I was completely incapacitated in a "life-or-death" situation for at least 10 or 12 seconds by my panic response.

I have been presented with other unexpected scary situations, like when a german shepard lunged at me from some hedges while I was jogging on a dark night. Under this stimulus, I was equally surprised of my response, when I leaped into the air, assumed an instinctive defensive posture when my feet hit the ground and then immediately proceeded to scream and attack the dog with kicks and punches before I even fully realized what was happening.

I am not prone to panic attacks, but from my personal experience it seems impossible to make someone completely immune to falling victim to a panic attack in all situations. Apparently panic can occur almost instantaneously in certain situations.

 

[freediver]

One of the funniest things I have ever seen, is someone trying to reason with a person about their phobia. They try to use reason on an unreasonable fear. I used to be scared of sharks. It took a setermination on my part and plunging myself into the situation in order to defeat it. Logic had very little to do with it.

I take this to mean that you don't believe a fear can be unlearned using reason or logic? You weren't born with a fear of sharks. I would say that by using reason and logic you lowered the perception of risk that the sharks instilled upon you creating less stress on you while in the water.

If the onset of this panic is due to a sudden environmental change, then there may be no time to detect it's onset. This is especially true if we add in any physiological factors.

Yes and the physiological factors we attempt to control. The sudden environmental change may very well lead to the panic but again this is a learned fear. We may not always be able to detect the onset of stressors that may lead to panic but if we could identify/recognize them, we can always control our response to them.

 

[The Chairman]

I take this to mean that you don't believe a fear can be unlearned using reason or logic? You weren't born with a fear of sharks. I would say that by using reason and logic you lowered the perception of risk that the sharks instilled upon you creating less stress on you while in the water.

Without the proper motivation, logic has no way of changing anything. Trying to rationalize an irrational fear is an exercise in futility.

Yes and the physiological factors we attempt to control. The sudden environmental change may very well lead to the panic but again this is a learned fear. We may not always be able to detect the onset of stressors that may lead to panic but if we could identify/recognize them, we can always control our response to them.

Not all fears are learned. There are many atavistic fears that we have little control of.

It is truly easy for those who have few to no fears to judge those who do. The bottom line for most fears and almost ALL phobias, is that they are irrational: ie beyond reason. Quite often, those who have these irrational fears never really conquer them completely. Rather, they only suppress them. Like a restrained spring, the repressed fear needs only a small opening to escape and to create panic in an instant. Only the diver in question can determine what their level of stress is before the panic spring escapes. While training may ameliorate the onset of panic, nothing can fully prevent it from happening.