Week 2- trauma Flashcards
What is type 1 trauma?
Single incident trauma, single event
What is type 2 trauma?
Repetitive trauma. e.g. ongoing abuse, hostage taking.
What are the two responses to threat?
Freeze- distant or inescapable threat
Flee- threat escapable or nearby.
What is tonic immobility?
You freeze if you think you are going to die. Its not a conscious decision. Especially occurs when there is direct physical contact with predator/aggressor.
Name some features of tonic immobility?
Decreased vocalisation Rigidity and paralysis Muscle tremors in extremities Chills Unresponsive to pain
Why does tonic immobility enhance survival?
Evidence that predators are less likely to attack immobile prey.
If they do attack- immobility causes them to loosen grip increasing the chances of escape.
Some attackers lose interest if the victim is immobile.
What does increased proximity to a predator cause in the brain?
Shifts brain activation from prefrontal cortex to the midbrain, specifically the superior colliculi and periaqueductal grey (PAG). These are the regions responsible for active and passive stress responses.
What is PTSD said to be due to?
A deficiency in top-down modulation of amygdala activation by the pre-frontal cortex.
What is defence activation made up of?
Three looping systems
What makes up the first loop of the defence activation?
Midbrain/brainstem origin (periaqueductal grey and superior colliculi)
What makes up the second loop of the defence activation?
Mesolimbic-dopamine system
What makes up the third loop of the defence activation?
Stimulus response learning system.
Describe the changes in cortisol levels in PTSD
Acute stress causes increase in cortisol levels, however patients with PTSD have the lowest rise in cortisol levels. (cortisol acts to stop the stress response via negative feedback).
Chronic PTSD has low serum cortisol levels.
NOTE on PTSD
For some patients, a small amount of trauma is enough to cause PTSD because they are susceptible to it. However there are also some traumas so significant that you don’t need to be susceptible to it to develop PTSD.
What psychological reactions may happen after trauma?
Depression Grief reactions Panic attacks Agoraphobia Alcohol/drug dependence Brief hypomania Specific phobias PTSD
