Temporal Dynamics of the Defense Cascade

dc.contributor.authorNackley, Brittany B.en
dc.contributor.committeechairFriedman, Bruce H.en
dc.contributor.committeememberOllendick, Thomas H.en
dc.contributor.committeememberJones, Russell T.en
dc.contributor.departmentPsychologyen
dc.date.accessioned2020-09-18T17:06:23Zen
dc.date.available2020-09-18T17:06:23Zen
dc.date.issued2020en
dc.description.abstractUnderstanding physiological responses to threat can inform therapeutic interventions for phobias, anxieties, and PTSD. The defense cascade is reviewed as a theoretical model that predicts behavioral and physiological responses to threats. Nineteen undergraduates (five male), average age 19.4 experienced a novel virtual reality (VR) threat scenario while their physiology was measured. The Subjective Units of Distress Scale (SUDS) was used as a self-report indicator of distress in the research setting. Averaged SUDS reports suggested that the VR stimulus was experienced as threatening for most participants, but their autonomic response patterns did not fit those predicted by the defense cascade. Participants who had scored high on adaptive response questionnaires tended to show uncoupled ANS activation during baseline, but varied across the stimulus condition. Nearly all participants showed either coactivation or reciprocal activation during the stimulus period except those reporting the most dissociative trauma experiences, who mostly showed uncoupled ANS activation.en
dc.description.abstractgeneralThe more we understand about how people’s bodies and their energies act when they feel threatened, the better we can find help for folks who struggle with anxiety, trauma or other challenging conditions. This research uses a theoretical model called the defense cascade to explore how people respond mentally and physically to threatening situations. Nineteen undergraduates went through a virtual reality (VR) experience that was designed to feel threatening while their body and its energy systems were measured. A scale was introduced called the Subjective Units of Distress Scale (SUDS) and was used to help the researchers understand how distressed people felt while they were in the VR experience. Averaged SUDS reports suggested that the VR stimulus was experienced as threatening for most participants, but their body response patterns did not fit those predicted by the defense cascade. Participants whose questionnaire responses suggested they were not anxiety-prone or traumatized, tended to show bodily activation that uncoupled their two autonomic bodily systems during a baseline period before the threatening stimulus. However, their autonomic responses during the stimulus period varied. Nearly all participants showed either both autonomic systems acting together or only one system acting in a mutually exclusive way to the other system during the stimulus period. This was the case for most participants except those reporting the most trauma involving dissociative experiences. This latter group mostly showed uncoupled autonomic bodily patterns.en
dc.description.degreeM.S.en
dc.format.mediumETDen
dc.identifier.urihttp://hdl.handle.net/10919/99987en
dc.language.isoen_USen
dc.publisherVirginia Techen
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivatives 4.0 Internationalen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectdefense cascadeen
dc.subjectphysiologyen
dc.subjectautonomic nervous systemen
dc.subjectsympathetic nervous systemen
dc.subjectparasympathetic nervous systemen
dc.subjecttime seriesen
dc.subjectSubjective Units of Distressen
dc.subjectSUDSen
dc.subjecttraumaen
dc.subjectautonomic spaceen
dc.subjectcardiac autonomic balanceen
dc.subjectcardiac autonomic regulationen
dc.titleTemporal Dynamics of the Defense Cascadeen
dc.typeThesisen
thesis.degree.disciplineBiological Psychologyen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameM.S.en

Files

Original bundle
Now showing 1 - 4 of 4
Loading...
Thumbnail Image
Name:
Nackley_BB_T_2020.pdf
Size:
5.19 MB
Format:
Adobe Portable Document Format
Loading...
Thumbnail Image
Name:
Virginia Tech Mail - Re_ Permission to reproduce Defense Cascade graph.pdf
Size:
67.75 KB
Format:
Adobe Portable Document Format
Loading...
Thumbnail Image
Name:
VT IRB-19-585 Authorization Letter.pdf
Size:
96.29 KB
Format:
Adobe Portable Document Format
Loading...
Thumbnail Image
Name:
(IRB Aprvd) IRB-19-585-Research Protocol (HRP 503)-v3.0-20200113-CLEAN.pdf
Size:
463.67 KB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
Name:
license.txt
Size:
1.5 KB
Format:
Item-specific license agreed upon to submission
Description:

Collections