Monday, December 17, 2012

Fear Conditioning.

by The Evil Dr. Schmitt-Rottluff.

The intertwined dance of aggressor and victim reveals the social complexity of the encounter. Does fear ever go away?

This phenomenon has been studied in an emotional spin on good old Pavlovian conditioning in a variant called fear conditioning. An unsuspecting laboratory animal is introduced into a dimly lit cage, which is equipped with a speaker and wired with a floor grid. In the initial session, an unfamiliar but otherwise innocuous tone beeps into the chamber for a minute or two.

The mildly curious rodent pads around the cell, sniffing its environment, but is otherwise unconcerned by the noise. In the second session, “the fun begins.” When the beeping starts, so does a mild electric shock to the feet of the animal. The creature crouches and trembles, its cardiovascular system ratcheting up into overdrive. It only takes a few sessions, sometimes as little as a single session, and the connection between the tone and the painful electric jolt is firmly cemented in the creature’s mind.

Very quickly the sound alone is enough to elicit the fear response; and the rodent freezes in place, heart rate racing, blood pressure soaring to three or even four times the values observed in the initial pain-inducing sessions.

What is even more striking about this research, the associations between fear and environment are so strongly forged that many researchers believe they may be permanent.

“A period of safety illustrates this lingering power of conditioned fear. If the tone sounds many, many times without the shock, the intensity of the rat’s fearful response slowly decays, neurobiologists call this deceptive calm extinction. But the connection between fear and sound hasn’t dissolved; it has merely retreated underground. One shock—or even the rat equivalent of an overwrought Monday morning—and the fear circuit is reactivated,” according to Debra Niehoff, Ph. D. “The rat cowers in a corner of the cage, clearly anticipating the long-ago shock. The brain has not erased the fearful memory, it has simply created…a fragile detour that can be blasted away by stress or familiar environmental cues.”

The briefest exposure to stress can have profound results on behaviour. In a procedure known as time-dependent sensitization, (as described in the previous chapter,) a mouse was placed in one chamber of a two-room test cage. Ten seconds later, a light was flashed and a door revealed to reveal a nice, inviting, dark escape hole. When they darted in, they received a stiff shock.

For the next six weeks, the mice were returned to the lighted chamber for one minute every week. The door was kept closed, but the animals were periodically reminded of their previous experience. With each reminder, these stress-sensitive mice became more and more fearful. They jumped higher and faster at sudden noises, when placed in a maze, they exhibited symptoms of fear, some crouching in corners and others racing from wing to wing of the maze. Of the original thirty animals, twenty-five never completed the experiment, having killed each other in episodes of vicious fighting.

The neurons, the neural pathways regulating fear turn out to be very similar to those regulating aggression, and can be kindled by the same stimuli.

The response to stimuli can change over time, and the initial response to the first incident of harassment can be quite muted. Reports from veterans dating back to WW I, plus more recent work into PTSD has shown veterans, as well as adult survivors of physical and sexual abuse during childhood, had significant deficits in short-term memory. This is especially true for the recall of verbal information.

But even hardened and objective researchers were taken aback by the results of MRI (Magnetic Resonance Imaging) scans in a group of twenty-six veterans with PTSD and a carefully matched control group of twenty-two other subjects.

Patients with PTSD had clear evidence of a structural defect, an average eight per cent reduction of an area on the right side of the brain in the region of the hippocampus; and the greater the area reduction observed, the greater the memory deficit. High levels of stress and threat over a long period of time, cause structural and functional changes in the brain.

Simply put, a single spouse with dependent children undergoing harassment will suffer long term effects, even after the situation is resolved. “Harassment is the gift that keeps on giving.” The children will also suffer long-term effects. In a recent editorial in a community newspaper it was stated, “The children of broken homes cause huge costs for society.”

“Trauma not only leaves visible marks we can observe on the outside, imaging studies suggest that it also leaves marks we can observe on the inside,” according to a well-known researcher, John Krystal.

Whether trauma is the result of violence in combat, a criminal act, or parental rage, brain imaging demonstrates that one reason victims can’t “just get over it,” is that the violence has been almost literally “seared into their brain.”

Adrenaline is well known for its ability to crank up heart rate, respiration and metabolism in the face of an emergency. But it is the sympathetic nervous system and norepinephrine, the chemical precursor of adrenaline that alerts the adrenal glands in the first place, this triggers the heart, lungs, vasculature, (e.g. increased blood flow), stomach, and muscles. Thus the familiar symptoms of emotional arousal.

The perception of threat is a brain process. Alarming events, disturbing thoughts, even the apprehension caused by the arrival of an envelope from a lawyer or the income tax people; wakes up the sympathetic nervous system and triggers defensive responses.

This is the neural aspect of the flight or fight decision-making process.

Painful to remember, trauma cannot be forgotten. Symptoms like flashbacks and intrusive memories are part of emotional memory, the darker side of a neural process that can also remember in exquisite detail every aspect of the birth of a child.

So are the intense feelings of fear, rage, and panic that survivors experience when confronted with even the most trivial similarities between events in the present and violent events or traumatic events in the past. Their bodies continue to react to certain physical and emotional stimuli as if there were a continuing sense of annihilation. Fear conditioning stimulates the startle reflex in humans. Researchers at the National Centre for Post-traumatic Stress Disorder reported that eye blink responses to a blast of white noise were significantly higher in Desert Storm veterans suffering from PTSD and women who had suffered childhood abuse, compared to otherwise normal test subjects.

The consequences of violence, the terror of seconds suspended between life and death, do not vanish, for they have been burnt into our memory banks. Impossible to erase, they are all too easily reawakened.


(Photo: white rat in sleep deprivation experiment. If he falls asleep, he gets wet. Jean-Etienne Poirrier.)

The Evil Dr. Schmitt-Rottluff also appears in 'On the Nature of the Gods,' available from Amazon and other fine online retailers. This links to the paperback version.

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