The Role of Expectations in the Development of Intrusive Memories
- Conditions
- Posttraumatic Stress Disorder
- Interventions
- Behavioral: Negative Expectation ManipulationBehavioral: Positive Expectation Manipulation
- Registration Number
- NCT03950869
- Lead Sponsor
- Philipps University Marburg Medical Center
- Brief Summary
In the experimental study, the well-established trauma film paradigm will be used to investigate the impact of expectations on the development of intrusive memories as a hallmark symptom of PTSD.
- Detailed Description
The study aims to examine the influence of different expectations on the development of intrusive memories by using a well-established experimental paradigm - the trauma film paradigm. In healthy volunteers, intrusion-like symptoms are to be induced with an analogue stressor, i.e., aversive film clip footage (trauma film). After viewing this so-called trauma film, the expectations of intrusions during the following week are manipulated by assigning participants randomly to three different groups. In the first group, negative expectations are induced (experimental group 1), the second group is exposed to positive expectations (experimental group 2) and a third group does not face any kind of manipulation of their expectations (control group). Participants are asked to report occurring intrusions in a diary during the following week and are invited to a subsequent cued laboratory inquiry at follow-up.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 90
- healthy volunteers
- fluent in German language
- history of traumatic experiences (LEC-5)
- presence of a mental disorder (SCID-I according to DSM-IV)
- cut-off in depression screening (PHQ-9)
- current suicidal thoughts/behavior or non-suicidal self-injury behavior (C-SSRS)
- medical history of heart disease or epilepsy
- history of fainting
- work experience in the medical field (e.g., nurses, paramedics, etc.)
- visual impairment
- students of psychology and medicine
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Negative Expectations Negative Expectation Manipulation Expectations on the severity and frequency of intrusions are increased while expectations on the controllability of intrusions are decreased. Positive Expectations Positive Expectation Manipulation Expectations on the severity and frequency of intrusions are decreased while expectations on the controllability of intrusions are increased.
- Primary Outcome Measures
Name Time Method Frequency and severity of intrusive memories: Daily intrusion diary Record of any intrusive memories of the trauma film content for Days 1 to 7 after the experimental manipulation. Participants are asked to complete a pen-and-paper diary 7 days in a row, reporting on intrusive memories in reference to the trauma film. They are asked to state the number of intrusions per day; each day of the diary is labeled and split into three sections (morning, afternoon, evening), and they are asked to mark in a box in the appropriate section when they experienced an intrusion. For each intrusion, they indicate the quality of the intrusion (image, thought or both), the intensity of and distress caused by the intrusion both on a scale ranging from 0 ("not at all") to 10 ("extremely"), the content of the intrusion, and the situation in which the intrusion occurred. Intrusive memory frequency across 7 days are calculated, whilst higher sum scores represent more intrusions. Severity of intrusions are calculated by combining the average score of the intensity and distress scale across all intrusions, whilst higher values indicate higher intensity/distress of reported intrusions.
- Secondary Outcome Measures
Name Time Method Distress caused by the trauma film: Impact of Event Scale-Revised (IES-R) At the follow-up measurement (7 days after the experimental manipulation). Participants are asked to respond 22 items in reference to the trauma film (e.g., "Pictures about the film popped into my mind.") by indicating how often each reaction occurred during the past seven days with respect to the film they watched last week. Items are rated on a 4-point-Likert-scale ranging from 0 ("not at all"), 1 ("rare"), 3 ("sometimes") to 5 ("often"). The IES-R consists of three subscales: "intrusion", "hyperarousal", and "avoidance". The total score (sum score for the total scale comprising the sum scores of all three subscales) is calculated ranging from 0 to 110 with higher values represent a worse outcome, i.e., higher total distress due to the trauma film in the past week. In addition, the sum score for the intrusion subscale is separately calculated ranging from 0 to 35 (Items 1, 3, 6, 9, 14, 16, 20) with higher values represent more intrusions due to the trauma film in the past week.
Laboratory assessment of intrusive memories: Intrusion Provocation Task (IPT) At the follow-up measurement (7 days after the experimental manipulation). In the Intrusion Provocation Task (IPT), participants are presented with a ten-second long neutral still image from each of the film clips. Immediately afterwards for the next two minutes, they are allowed to think freely and report intrusions by raising a finger. The investigator counts how often the participant lifts his finger in the two minutes. The IPT intrusion score is calculated by the total frequency of intrusions, whilst higher values represent more intrusions.
Trial Locations
- Locations (1)
Division of Clinical Psychology and Psychological Interventions, Department of Psychology, Philipps University Marburg
🇩🇪Marburg, Hessen, Germany