CTSS Neurobiological Impacts of Trauma 2 — Questions and Answers
Question 1: Polyvagal theory, developed by Stephen Porges, proposes that the social engagement system supporting safety and connection is primarily mediated by which structure?
- Sympathetic chain ganglia
- Vagus nerve (cranial nerve X) (Correct answer)
- Trigeminal nerve (cranial nerve V)
- Glossopharyngeal nerve (cranial nerve IX)
Correct answer: Vagus nerve (cranial nerve X)
Porges' polyvagal theory identifies the myelinated ventral vagus nerve as the pathway for social engagement behaviors, including facial expression and vocal prosody, that signal safety in the environment.
Question 2: Epigenetic changes resulting from trauma exposure primarily affect biological functioning by:
- Permanently altering the physical DNA sequence of chromosomes
- Changing blood type and immune cell markers
- Modifying gene expression without altering the underlying DNA sequence (Correct answer)
- Affecting only somatic cells, never reproductive cells
Correct answer: Modifying gene expression without altering the underlying DNA sequence
Epigenetic mechanisms such as DNA methylation and histone modification alter how genes are expressed in response to trauma without changing the DNA sequence itself, and these changes can persist and potentially be transmitted.
Question 3: Which stress hormone, when chronically elevated due to repeated trauma exposure, is most strongly associated with hippocampal volume reduction?
- Oxytocin
- Dopamine
- Cortisol (Correct answer)
- Melatonin
Correct answer: Cortisol
Chronically elevated cortisol exerts neurotoxic effects on hippocampal neurons, inhibiting neurogenesis and promoting dendritic atrophy, which is why smaller hippocampal volume is a neuroimaging finding in chronic PTSD.
Question 4: The clinical concept of 'window of tolerance' describes the neurobiological state in which a trauma survivor:
- Has learned to tolerate traumatic memories without emotional response
- Can process trauma material without shifting into hyperarousal or hypoarousal (Correct answer)
- Tolerates the maximum dose of trauma-focused medication safely
- Enters a dissociative state that protects from further trauma exposure
Correct answer: Can process trauma material without shifting into hyperarousal or hypoarousal
The window of tolerance, described by Daniel Siegel, is the optimal arousal zone where the nervous system remains regulated enough for the cortex to process and integrate traumatic material effectively.
Question 5: In trauma neurobiology, peritraumatic dissociation is most closely associated with which nervous system mechanism?
- Hyperactivation of the norepinephrine system causing amygdala flooding
- Increased prefrontal cortex control over the amygdala
- Dorsal vagal shutdown resulting in decreased arousal and disconnection (Correct answer)
- Elevated cortisol sustaining prolonged HPA axis activation
Correct answer: Dorsal vagal shutdown resulting in decreased arousal and disconnection
According to polyvagal theory, when fight-or-flight fails, the ancient dorsal vagal pathway produces a shutdown/dissociative response characterized by immobility, numbness, and reduced awareness.
Question 6: Intergenerational trauma transmission at the biological level is primarily explained by which mechanism?
- Direct DNA mutation passed unchanged to offspring
- Epigenetic modifications affecting gene expression patterns in subsequent generations (Correct answer)
- Hormonal changes that permanently alter blood chemistry before conception
- Cerebrospinal fluid transfer of stress proteins during birth
Correct answer: Epigenetic modifications affecting gene expression patterns in subsequent generations
Research on intergenerational trauma shows that epigenetic modifications to stress-response genes (such as methylation of glucocorticoid receptor genes) can be transmitted to offspring, altering their HPA axis reactivity.
Question 7: Somatic experiencing therapy targets which primary neurobiological system to resolve trauma symptoms?
- Declarative memory and hippocampal reconsolidation pathways
- Procedural and implicit memory within the autonomic nervous system (Correct answer)
- Explicit verbal processing through Broca's area activation
- Frontal lobe executive function and cognitive reappraisal networks
Correct answer: Procedural and implicit memory within the autonomic nervous system
Somatic experiencing, developed by Peter Levine, works with the autonomic nervous system's procedural and body-based implicit memory to complete interrupted defensive responses and restore nervous system regulation.
CTSS Neurobiological Impacts of Trauma 2
Polyvagal theory, developed by Stephen Porges, proposes that the social engagement system supporting safety and connection is primarily mediated by which structure?