Psyco 350 Lec #22– Slide 4 DSM-IV Criterion A The person has been exposed to a traumatic event in which both of the following have been present: (1 – The Event) The person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others (2 – Peritraumatic Reaction) the person's response involved intense fear, helplessness, or horror.
Psyco 350 Lec #22– Slide 5 DSM-IV Criteria B-F B. reexperiencing of the traumatic event C. avoidance of stimuli associated w/ trauma and numbing of general responsiveness D. increased arousal E.symptoms present for more than 1 month F.clinically significant impairment in social, occupational, or other important areas of functioning
Psyco 350 Lec #22– Slide 7 DRT: Holmes, Brewin, & Hennesy (2004) Two type of event information 1. Verbally Accessible Memory (VAM) “ordinary autobiographical memory” requires “high-level of conscious processing” 2. Situationally Accessible Memory (SAM) “stores sensory information, mostly… in the form of visual images”
Psyco 350 Lec #22– Slide 8 DRT: SAM on Its Own SAM Retrieval: triggered by exposure to “relevant” cues accessed automatically Reaction to SAM: re-experience event emotion-laden flashbacks strong affective response
Psyco 350 Lec #22– Slide 9 DRT: Further Assumptions VAM blocks SAM: controls & contextualizes SAM-based responses WM-systems & the creation SAMs & VAMS: Verbal WM required for VAMs Visuo-spatial WM required for SAMs
Psyco 350 Lec #22– Slide 10 DRT: Implications Creation of PTSD-evoking representations: Dissociative reactions to traumatic event knocks-out WM capacity necessary for VAM creation SAM encoded regardless VAM-less SAMs PTSD symptoms
Psyco 350 Lec #22– Slide 11 Testing DRT w/ Dual Task Design General Paradigm: Watch horrific film while engaged in either: (a) spatial task (b) verbal task General Predictions: spatial task knock out SAM reduce PTSD symptoms verbal task knock out VAM increase PTSD symptoms.
Psyco 350 Lec #22– Slide 12 The Experiment(s) Participants: Healthy, young adults 20/group Materials: 12.5 min film – actual traffic accidents Instructions: Watch film for later memory test
Psyco 350 Lec #22– Slide 13 The Experiment(s) Concurrent Tasks (between-subjects): Control – no concurrent task Visual-spatial inference – tap out a preseficed pattern on buttons Verbal-interference – count backwards by 3s Main DV: # of intrusive memories recalled in 7-day diary
Psyco 350 Lec #22– Slide 14 The Experiment(s) Expectation: Counting interferes w/ VAM creation Tapping interferes w/ SAM creation Prediction: # intrusive memories: counting > control > interference
Psyco 350 Lec #22– Slide 15 Results: # of Intrusions As predicated: tapping < control
Psyco 350 Lec #22– Slide 16 Results: # of Intrusions As predicated: tapping < control counting > control
Psyco 350 Lec #22– Slide 17 DRT: Discussion DRT correctly predictions intrusion patterns. But: Are these data PTSD-relevant? If so, –How do VAM-less SAMs create PTSD? –How do VAMs inhibit SAM-trigged responses? –PTSD in non-humans?
Psyco 350 Lec #22– Slide 18 The Mnemonic “Model”
Psyco 350 Lec #22– Slide 19 A Memory-based Model of Post-traumatic Stress Disorder: Evaluating Basic Assumptions Underlying PTSD Diagnosis A telling and misleading title. Rubin, Berntsen, & Klindt-Johansen. (2009) Psychological Review
Psyco 350 Lec #22– Slide 21 “most direct evidence for... memory...as a causal agent is that observation that eliminating or enhancing memory in various ways changes PTSD symptom severity” Support for Mnemonic Position
Psyco 350 Lec #22– Slide 22 Amnesia reduces or eliminates PTSD Organic amnesia – traumatic brain injury Pharmacologically-induced amnesia –Propranolol treatment reduced PTSD symptoms in emergency room patients (Pitman et al, 2002) Childhood Amnesia –Before 3: No PTSD –3-to-7: PTSD symptoms increase w/ age –After 7: PTSD unrelated to age Memory & PTSD
Psyco 350 Lec #22– Slide 23 PTSD symptoms , as availability of traumatic memory Method: correlate Centrality of Event Scale (CES; B&R, 2006, 2007 ) w/ PTSD symptom. –CES measures importance of traumatic event: To personal identity As a turning point As a reference point Results: r ’s ranging from.35 to.51 Memory & PTSD
Psyco 350 Lec #22– Slide 24 Is the DSM “model” a strawman? What is required to make the mnemonic “model” a model? Does anyone ever consider the material consequences of traumatic events and their relation to PTSD? Questions