Sunday, April 14, 2013

Psychobiology of Stress, physical and psychological reactions

Defensive Reactions are the cluster of innate reflexive responses (which are autonomic) to environmental threat.

Unconditioned stimuli become conditioned via paired associate learning, and the previously neutral stimulus now elicits a conditioned (and often autonomic response)

Hyper vigilance (scanning) the total environment is autonomic, and causes a great deal of simultaneous, yet erroneous, “accidental” conditioning

Think multi-modal: Behavior-Affect-Sensation-Images-Cognitions-Interpersonal Relationships-Drugs/Biology-Social Systems-Spirituality

To compensate for chronic hyper arousal, traumatized people seem to shut down; on a BEHAVIORAL level by avoiding stimuli reminiscent of the trauma, and on a PSYCHOBIOLOGICAL level by emotional numbing. Numbed responsiveness to the environment, punctuated by intermittent HYPERAROUSAL in reaction to a wide range of conditioned stimuli.

The stimuli that precipitate emergency “flight or fight” response(s) may not be conditioned “clearly” enough, so many “triggers” not directly related to the traumatic experience may precipitate intense and extreme reactions (very difficult to understand-cognition by the client)

The loss of AFFECTIVE modulation is central to understanding (PTSD) or anxiety reactions. Traumatized persons lose (or certainly experience impairment) the capacity to use AFFECT states as signals. Feelings are not any longer used (accurately) as cues to attend to incoming information, and arousal is likely to precipitate an autonomic “fight or flight” response…this makes traumatized persons freeze or over react to seemingly innocuous stimuli or provocation.

Heightened physiological arousal (SENSATIONS) to sounds, images, and thoughts (COGNITIONS) related to specific traumatic incidents is common. Increased heart rate, skin conductance, and blood pressure PAIRED with cognitions and feelings, repeatedly CONDITIONS this erroneous association(s).

Kolb was the first to propose that excessive stimulation of the central nervous system at the time of trauma may result in permanent neuronal changes that have a negative effect on learning, habituation, and stimulus discrimination. CORTISOL is produced when the perception of threat is initiated (Antecedent) to flight or fight. Amygdala-excessive stimulation interferes with hippocampus functioning, which inhibits cognitive evaluation of experiences. Memories are then stored in sensorimotor modalities: somatic sensations and visual images.

Abnormal acoustic startle response (ASR) is a characteristic sequence of muscular and autonomic responses elicited by sudden and intense stimuli. As Cortisol is increased it causes a challenge to the person to habituate, or turn the autonomic response off…so the habituation response is hampered…and the synapses where the (hyper) Cortisol production is occurring begin to “break off” causing permanent conditioning in the brain (like information being burned into the disc of your brain). Tangles of the brain (dendrite-axon) fall away or break.

Extreme stress is accompanied by the release of endogenous neuro-hormones (Cortisol, epinephrine & nor epinephrine, and endogenous opiates). Chronic stress (TYPE II trauma) causes the resting state (the normal level of these neuro-hormones) to be seriously (permanently?) altered. Chronic exposure to stress affects both acute and chronic adaptation; it permanently alters how the person deals with the environment on a day-to-day basis and interferes with coping with subsequent acute stressors.

Catecholamine (nor epinephrine) (increased) precipitated panic attacks in 80% of subjects and 60% of flashbacks.

Serotonin (increase) depression and affect impact-Decreases- increase the probability of impulsivity and aggression. Low levels impact the ability to modulate arousal (hyper-excitability, hyper sensitivity) SSRI seem to be so effective at helping reduce the obsessive thinking of persons with OCD and OCD traits in trauma.

Endogenous opioids, which inhibit pain and reduce panic, are secreted after prolonged exposure to severe stress. Memory is impaired when the person can longer actively influence the outcome of a threatening situation. Freeze-Numbing responses may serve the function of allowing the person to not “consciously experience” or to not remember situations of overwhelming stress (thus also prevent them from learning from he experience.  

State Dependency of the “Learning”: memories (somatic or symbolic) related to trauma are elicited by heightened arousal or otherwise altered state of mind is retrieved more readily when persons are brought back to that particular state of mind. State dependent memory retrieval may be involved in disassociation phenomena in which traumatized persons may be wholly or partially amnesic for memories or behaviors enacted in an altered state of mind (arousal). It also provides the base for re-exposure/recollection/recall work and then either desensitization or critical stress debriefing, or EMDR.

Conceivably traumatic memories emerge not in distorted fashion, but as affect states (FEELINGS) somatic (SENSATION), and/or visual images (nightmares or flashbacks) that are timeless and unmodified (without re-programming) forever. Think about a slide projector, or discs in your computer. Once tuned to that slide al of the affect, cognition, sensations, and physiology associated with that slide are autonomically brought back up.

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