Use of a Psychophysiological Script-driven Imagery Experiment to Study Trauma-related Dissociation in Borderline Personality Disorder

Our study was approved by the Ethical Committee at the Ulm University. All investigation proceedings were non-invasive and conducted in accordance with the guidelines for good clinical practice and the Declaration of Helsinki.

1. General procedures for the preparation of the psychophysiological experiment

1. Obtain ethical approval for the protocol and written informed consent from all participants after giving them detailed information (including information about the possibility of earlier termination without any negative consequences).
2. Prepare the introductory instruction for the experimental procedure and the participant tasks over the course of the experiment, record it, and save it in the appropriate format within the stimuli presentation software.
   NOTE: Here is an example how to formulate the initial instruction: "This measurement records your physiological activity while listening to scripts about personal events. This happens through the electrodes attached to your forehead, shoulders, and hand. Try to take a comfortable position in the chair. Your room is closed to shield noises. I can see you through the window, just as you can see me. If something is not right, you can always give me a sign and I'll be right next to you. It is important that you sit still during the measurement and do not move. There are regular breaks in which you can move. Overall, the investigation will take about half an hour. Each script presentation consists of four consecutive 30-second periods: rest condition, script listening, imagination, and relaxation. Please listen carefully to each script, and try to vividly imagine the illustrated experience in chronological order, both during the script presentation and afterwards, until you hear a new instruction. Each script is displayed totally three times. The measurement starts from now in about one minute, as soon as your physiological readings have reached a stable level. So you can relax first."
3. Proceed similarly for the relaxation and self-report instruction that will be presented between each two scripts.
   NOTE: Here is a possible formulation of such an instruction: "Please relax. If you want, you can now move a little bit. Fill the questionnaire in by marking the answer options that best describe your feelings during the imagination of the event. Afterwards, try to find again a comfortable position, try to sit still again and continue to relax. Soon you will hear another script. Please listen carefully to it and try to imagine as vividly as possible and in chronological order the illustrated experience until you hear the next instruction."
4. For the presentation of auditory instructions and scripts, use a stimulus computer and a scripting language-based computer software. Play back each script three times and insert four sequential 30-s periods within each script presentation as follows:  resting baseline, read (listening to the spoken script), imagery (imagination of the described experience), and recovery (see Figure 2). In-between two script presentations, reserve a period of 1 – 2 minutes for filling the self-report measures in.
5. Use an appropriate recording computer and software to collect physiological data during the experiment. Depending on the software for recording physiological data, prepare the necessary channels for the recording of physiological parameters (SC and HR).
6. Set up markers or use separate channels for the depiction of the time course of the instructions and script presentations.
   1. To subsequently facilitate the removal of artifacts from the physiological data, incorporate the possibility to flag movements. Save this recording set-up to allow its availability for all planned measurements.

2. Participant selection

NOTE: For the selection and recruitment of the clinical study participants, available standards were considered (Sullivan-Bolyai et al., 2007)²⁵.

1. If possible, recruit clinical participants from a clinical setting for obtaining reliable information regarding the inclusion and exclusion criteria. Review medical records and clinical files, consult clinical-therapeutic staff (if possible), and ask participants to ascertain relevant information for the participant selection.
2. Select clinical participants according to the following inclusion criteria: (a) ICD-10 diagnosis F60.31; (b) no medication (ask participants to abstain for 1 week prior to the laboratory experiment from any psychotropic medication or medication with potentially confounding autonomic effects, e.g. anticholinergic, α- or β-adrenergic blockers, digitals, and GABA-(A)-receptor-agonists including benzodiazepine); (c) legal competence, sufficient cognitive function, sufficiently stable psychological state, language proficiency; and (d) informed consent after detailed explanation of the objectives and procedure as well as answers to all the potential questions.
3. Exclude potential clinical participants if the following criteria apply: (a) internal, neurological, musculoskeletal or endocrinological disorders; (b) acute suicidal ideation, history of schizophrenia-type disorders or bipolar disorder, substance abuse within the last week.
4. Select control subjects with trauma histories, but without trauma-related or other psychological disorders and match those to the BPD group on age, gender, and education.
   NOTE: If BPD participants are recruited from a clinical setting, it is possible to select controls by approaching stuff and trainees from the same institution. Since most people experience at least one threatening event during their lives, it is not difficult to find healthy subjects with trauma histories.

3. Clinical assessment

1. Carry out an extensive evaluation of the psychological status of all participants with a focus on dissociative phenomena by clinically experienced investigators. Plan enough time for clinical assessment sessions (1 – 2 sessions of 60 – 90 min in length for each patient). Employ the following instruments (or equivalent ones):
   1. Approach potential clinical participants and, after informed consent (see above), hand over self-report questionnaires and instruct the participant appropriately.
   2. Obtain information on age, graduation, marital and occupational status.
      NOTE: In case study participants are recruited from a clinical setting, obtain sociodemographic from the documentation system of the clinic or routine data sets, if available.
   3. Inquire active substances consumed within the last weeks.
   4. Hand over the following instruments to the clinical participants.
      1. Use the Childhood Trauma Questionnaire (CTQ)²⁶, a 28-item questionnaire composed of five subscales, each containing 5 items (emotional abuse, emotional neglect, physical abuse, physical neglect, and sexual abuse) and one response bias subscale, the minimization and denial scale including three items; the items consist of statements to be rated by choosing one of five response options: (1) "never true," (2) "rarely true," (3) "sometimes true," (4) "often true," and (5) "very often true."
      2. Use the Life Event Checklist²⁷ for the further assessment of traumatic exposure.
      3. Use the Peritraumatic Dissociative Experiences Scale (PDEQ)²⁸, a 10-item self-report questionnaire measuring the extent of dissociation during the traumatic event and in the subsequent minutes and hours, accompanied by the instruction to fill in the questionnaire relating to their most severe traumatic event from the Life Event Checklist; score items on a 5-point Likert scale from 1 (not at all true) to 5 (extremely true).
      4. Use the initial questions from the Structured Clinical Interview for DSM-IV-TR Axis I Disorders and the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-I and SCID-II)^29,30 administrated as a self-rating screening instrument allowing a reduction of the number of domains to be evaluated for the diagnosis of Axis I and personality disorders.
      5. Use the Borderline Symptom List (BSL)³¹, a 99-item self-report instrument assessing the severity of borderline symptoms within the previous week on a 5-point Likert scale, with the following answer possibilities: "not at all," "a little," "rather," "much," and "very strong"; it contains the following scales: self-perception (19 items), affect regulation (13 items), self-destruction (12 items), dysphoria (10 items), loneliness (12 items), intrusions (11 items), and hostility (6 items).
      6. Use the Dissociative Experiences Scale (DES)³², a 28-item questionnaire to screen for dissociative symptoms; items assess the intensity of dissociative experiences from 0% of the time (never) to 100% of the time (always).
      7. Use the Symptom Check List-90-Revised (SCL-90-R)³³, a 90-item self-report instrument evaluating a broad range of psychological problems and symptoms; it contains nine scales (Somatization, Obsessive-Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Hostility, Phobic Anxiety, Paranoid Ideation, Psychoticism) and provides an index of symptom severity as the summary of the test; Construct items on a 5-point Likert-scale, from 0 (not at all) to 4 (very strong).
2. Proceed similarly for the self-report assessment of the control subjects, except for the following: (a) do not hand any SCID-I and SCID-II questions to control participants (see below in the clinical interview section); (b) for reasons of effort-reduction, employ only a short SCL-version instead of SCL-90-R (namely SCL-14)³⁴.
3. Arrange an appointment soon for the clinical interview, making sure that the participant can fill in all self-report measures by then.
4. At the beginning of the clinical Interview session, make sure that the participants filled in all self-report items in the first place, clarify unresolved items, and ask supplementary questions if necessary.
5. Discuss in-depth the items of the CTQ and Life Event Checklist by asking questions about the type and time of the inquired experiences; if necessary, correct the reports accordingly.
6. Use clinical standardized interviews for a differentiate diagnosis of both groups, as follows.
   NOTE: For reasons of effort reduction, use less extensive, but equivalent diagnostic instruments, to screen for mental disorders within the control group.
   1. Employ a broader battery of clinical diagnostic interviews for the clinical group: (a) the Clinician Administered PTSD Scale (CAPS)³⁵ for the diagnosis of PTSD; (b) the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D)³⁶ for diagnosing dissociative disorders; and (c) SCID-I and SCID-II interviews. Within the SCID interviews, conduct detailed inquiries only of the domains indicated by the self-report screening questions.
   2. Administrate only the Mini-International Neuropsychiatric Interview (M.I.N.I.)³⁷ to control participants. Based on this short structured clinical interview that allows diagnosis of psychiatric disorders according to both DSM-IV and ICD-10 criteria, ascertain the absence of mental disorders as well as the report of at least one past traumatic experience for the inclusion in the control group.

4. Procedures for the preparation of the psychophysiological experiment for each participant

1. At the end of the clinical interview section, ask the participant to specify and vividly describe the following three types of events: a traumatic one (in case of several traumatic experiences, instruct the participant to choose the one perceived as the worst), as well as two further individual experiences, a neutral one (e.g., cleaning the house, getting up early, or accomplishing other usual, slightly unpleasant everyday duties) and an everyday moderately positive event (e.g., enjoyable, relaxing or fun activities).
2. Within the event descriptions, inquire objective happenings (i.e., time, place, and context) as well as subjective information (i.e., emotions, sensory perception); take detailed notes allowing subsequent draft of the three verbal scripts (neutral, negative, and traumatic/aversive), which will be used as individualized emotional cues.
3. Make an appointment for the psychophysiological experiment within the next few days. Instruct the participant not to use any hand lotion or cream before the experiment.
4. Shortly after the clinical interview, compose verbal scripts of ca. 30 s duration that portray the three recalled personal experiences in the first person singular, present tense and register them on a voice recorder. Stick as much as possible to the individual formulations of the participants when describing their experiences (see Figure 1 for an example of traumatic script).
   1. Save them as audio files in the appropriate format and transfer them in the software program on the stimulus computer, serving to present the recorded auditory scripts.
5. Randomize the order of the script presentation. Adopt and save the resulted order of the scripts in the presentation program and put it on record, to account for it during data analyses.
6. Transfer and save the scripts in the resulting order into the presentation program. Use a scripting language based computer program which sends simultaneously auditory stimuli to a headphone and marker signals to the psychophysiological recording device at millisecond accuracy.
   NOTE: To avoid overstraining severely traumatized persons, use a pseudorandomized script sequence by beginning with the presentation of either a neutral or positive script and not leaving any consecutive presentations of the traumatic script. Based on our experience, we cannot confirm the participation of severely traumatized persons in such experiments as being potentially stressful in any way. For this reason, we regard the randomization of scripts under these constraints as only optionally.
7. Prepare the sheets and a pencil to collect subjective evaluative judgments of affective states during the script-driven imagery tasks. Employ a battery of visual analog 9-point Likert scales: (a) the Self-Assessment Manikin (SAM)³⁸ to evaluate the degree of arousal and dominance of the imagery; (b) similarly constructed scales to assess a set of other discrete emotions (e.g., fear, disgust); and (c) a short version of the scale Dissociation Tension Scale-acute (DSS-4)³⁹ to measure the state dissociation.
   NOTE: There are also other instruments assessing responses to trauma-related memory. We also suggest the use of the Responses to Script-driven Imagery (RSDI)⁴⁰ that additionally assesses re-experiences and re-experiencing and avoidance.
8. Prepare receipts of monetary compensations as well as the corresponding amount of money.
   NOTE: Our participants received 20 Euros.

5. Psychophysiological experiment

NOTE: Experimental set-up: The experiment followed the guidelines of psychophysiological measurements for the measurement of reactions to emotional cues⁴¹.

1. Conduct the psychophysiological experimental session in a sound-attenuated and temperature- and humidity-controlled laboratory connected via wires and window to an adjoining portion of the laboratory in which the experimental equipment is located.
2. Reserve enough time for conducting the physiological assessments (ca. 60 – 90 min per participant).
3. Once the participant arrived at the laboratory, show him/her the facilities and the recording instruments and explain their function.
4. Seat the participant in a comfortable chair and allow a period of adaptation to the recording environment while explaining again the procedure from the informed consent and answering any further questions.
5. Ask participants whether they used any hand lotion in advance and, if necessary, ask them to clean and dry their hands. Clean the required contact skin areas with alcohol solution pads. Attach physiological monitoring devices.
   1. Use adhesive, pregelled, 279 AgAg/Cl snap electrodes with circular contact areas, filled with an appropriate electrode gel: (a) for the SC measurement, place electrodes on the palmar surface (hypothenar and thenar eminence of the non-dominant hand); (b) for HR recording, use a Lead II configuration of three electrodes (two electrodes placed on the chest below the left and the right shoulder and reference electrode placed e.g. on the forehead). Apply headphones for the presentation of the instruction and scripts.
6. Perform a test run of the measurements to make sure that the participant hears the instructions and the physiological recordings are running well.
7. Begin the assessment approximately five minutes later in order to allow physiological readings to stabilize.
8. Pay attention to any movements of the participant during the experiment and, depending on the software, press a key/take notes to mark artifacts when necessary.
9. At the end of the experiment, remove all devices and clean the skin areas if requested. Provide monetary compensation and receipts. Offer the participant the opportunity to show and explain the physiological recordings. Ask whether the participant needs to share thoughts and experiences or to receive any further assistance.
10. Clean the electrodes with cold water to allow the removal of any gel rests.