Sexual Assault Prevention and Awareness Center

What is Trauma?

  • Trauma is a deeply disturbing or distressing experience

  • Trauma is both a psychological and physiological response

    • Psychological trauma- damage to a person’s psyche as a result of a deeply distressing event

    • Physiological trauma- injury or damage to a biological organism caused by physical harm from an external source

  • Trauma is interpreted by the body as a life-threatening experience


What happens in the brain during a traumatic event?

  • The HPA axis kicks in- stress and trauma stimulates the HPA axis

    • Hypothalamus

    • Pituitary Gland

    • Adrenal Gland

  • The HPA axis is a hormonal/nervous system connection of these three different structures

    • The hypothalamus acts on the pituitary gland

    • The pituitary gland acts on the adrenal glands

Hypothalamus & Pituitary Gland

  • The hypothalamus is the “Grand Central Station” of the brain

    • Communicates with other structures in the brain, including the pituitary gland

  • The hypothalamus stimulates hormone release from the pituitary gland

Adrenal Glands

  • Hormones released from the pituitary gland stimulates hormone release from the adrenal gland

  • There are 4 main hormones released from the adrenals during a traumatic event

    • Catecholamines

    • Cortisol

    • Opiates

    • Oxytocin

  • This combination of hormones acts as a signal that the body is experiencing a traumatic event and helps the body deal with it

  • All of these hormones are released in increased amounts during a traumatic event

Hormone Soup

  • Catecholamines → fight, flight, or freeze response

    • Many people have heard of the fight or flight response, but during a traumatic event there is also a freeze response

    • The freeze response is a mammalian instinct and it is basically like playing dead

      • Sometimes that is the safest thing to do

    • This freeze response results in tonic immobility (“rape induced paralysis”)

    • The survivor cannot move and is rendered immobile by the traumatic event

  • Cortisol → energy availability

    • Affects the amount of energy the body has available to fight or flee the situation

  • Opiates → Reduces physical pain

    • “Body’s natural morphine”

  • Oxytocin → Reduces emotional pain

    • “Feel good hormone”

    • Promotes positive feelings in the body

Hippocampus and Amygdala

  • The hippocampus and amygdala play critical roles in the processing and encoding of a traumatic event

  • The Hippocampus is the brain structure that processes information into memories

    • Helps to establish long term memory

    • The hippocampus encodes the information and then consolidates it

      • Encoding- organization of sensory information

        • Takes sensory information coming in and organizes it

      • Consolidation- group information and then sorting it

  • The amygdala specializes in the processing of emotional information

    • Traumatic events are harder to process because they are associated with emotional responses

  • The hippocampus and amygdala are very sensitive to the hormone soup mentioned before, making it harder to process, encode, and consolidate information and memories surrounding a traumatic event

How does this affect the survivor?

  • The hormone soup may result in a flat affect (most likely a result of the influence of the opiates)

    • This is often interpreted as a lack of an emotional response, which might make some people believe that the event did not actually happen

  • Fragmented and disorganized memory

    • As a result of the impaired abilities of the amygdala and hippocampus to encode and consolidate memories

    • Survivors may have trouble accurately remembering the assault

  • Emotions may change very rapidly

    • The survivor may exhibit rapid mood swings

Why is this important?

  • Patience is key because the survivor may have difficulty remembering the event and may have unpredictable emotions

  • It is important to know how trauma affects the temperament of the survivor

    • Because the survivor may exhibit a flat affect, it may seem like they are lying, not upset, or don’t care, but this is not true

    • Often times the survivor is also confused as to why they are acting the way they are

  • The survivor may have trouble remembering the event because of the physiological response to trauma

    • Law enforcement officials are often trained that a person may be lying if they can’t “get their story straight”

  • Prevention of secondary victimization

    • Secondary victimization- negative beliefs, attitudes, or behaviors that survivors may experience from others as a result of disclosing about the traumatic event

      • Often experienced as victim blaming or others being insensitive

    • Secondary trauma often exacerbates the effects of the trauma they’ve already experienced

      • It could be a severe as feeling like they are experiencing another assault

    • This can be avoided by educating others about the body’s response to trauma and how it may affect the actions and behavior of the survivor

      • Instead of questioning why they don’t act a certain way or do certain things, try to understand how the traumatic event may be affecting them


This information was largely adapted from Rebecca Campbell’s Webinar on the Neurobiology of Sexual Assault (December 3, 2012) (Retrieved from