neuroscience of trauma Flashcards
(8 cards)
What are the three main brain regions affected in PTSD and their alterations?
Amygdala: Reduced volume, hyperactivity
Prefrontal Cortex: Reduced volume, exaggerated dACC activity, reduced vmPFC activity
Hippocampus: Reduced volume and activity
What are the three core symptom categories of PTSD?
- Re-experiencing trauma (flashbacks, nightmares, distressing images)
Avoidance of trauma-associated stimuli (loss of interest in social situations, emotional detachment)
Hyperarousal (irritability, hypervigilance, exaggerated startle response)
What are the key characteristics of threat learning in PTSD?
Intact CS-US pairing learning
Main deficits in extinction learning and safety signal processing
Increased threat responses to safety signals
What is the key feature of extinction learning in PTSD?
Inability to learn that cues once linked with trauma are no longer dangerous. Extinction doesn’t erase original fear memory but creates a competing memory that can inhibit fear
What roles do the mPFC and hippocampus play in fear processing?
- dACC: Fear expression and enhances amygdala activity
vmPFC: Inhibits fear via amygdala
Hippocampus: Stores contextual information about fear learning and extinction
How is memory affected in PTSD?
Reduced hippocampal volume and functional activity
Deficits in both trauma and non-trauma related memories
Impaired hippocampal-dependent associations
Relatively preserved item recognition
What are the key principles of the Dual Representation Model in PTSD?
Strengthened emotional content via amygdala up-modulation
Impaired hippocampal function leading to weakened associations between content and context
What characterises threat detection in PTSD?
Hypervigilance and bias towards threatening stimuli
Increased amygdala activity to trauma-related and unrelated emotional material
Slower to disengage from threatening stimuli
