Updating vs. exposure to modify responses to traumatic stimuli: an experimental study, 2014

Pile, Victoria (2017). Updating vs. exposure to modify responses to traumatic stimuli: an experimental study, 2014. [Data Collection]. Colchester, Essex: UK Data Archive. 10.5255/UKDA-SN-851654

Data description (abstract)

Experimental data resulting from study investigating methods to reduce the conditioned fear response, intrusion frequency and Post-Traumatic Stress Disorder (PTSD) symptoms after viewing trauma films. The research used an experimental design that combined conditioning and trauma film paradigms. All participants underwent the same fear conditioning paradigm where trauma film stimuli (unconditioned stimuli) were paired with neutral stimuli (conditioned stimuli). Participants were randomly allocated to one of three US devaluation groups: ‘update’, ‘exposure’ and ‘control’. Exposure and updating techniques are frequently used as components of psychological therapy for PTSD but their relative effectiveness is unclear. This study aimed to compare the effects of updating the meaning of the trauma films (update group), further exposure to the trauma films (exposure group) and viewing non-traumatic films of related content (control group) on the reduction of the conditioned fear response and analogue PTSD symptoms. This study also investigated whether individual differences in fear conditioning are associated with the development of PTSD symptomatology.

Overall, the findings suggest that adding a cognitive update to a US devaluation process significantly reduces subjective distress ratings to fear conditioned stimuli as well as intrusion frequency and PTSD symptoms. Adding a cognitive update to US devaluation increased skin conductance response to the conditioned stimulus compared to further exposure to the films. In this study, having a larger conditioned acquisition response predicted higher intrusion frequency and distress and more PTSD symptoms.

Data creators:

Creator Name	Affiliation	ORCID (as URL)
Pile Victoria	King's College London

Sponsors:

N/A

Topic classification:

Psychology

Keywords:

Post-traumatic stress disorder, fear conditioning, early intervention, memory consolidation

Date published:

17 Nov 2017 19:01

Last modified:

17 Nov 2017 19:01

Coverage and Methodology

Collection period:

Date from:	Date to:
5 February 2007	31 August 2007

Geographical area:

London

Country:

United Kingdom

Data collection method:

Participants:

Participants were recruited by poster or email advertisements. One hundred and fifteen participants met inclusion criteria and completed the experimental task: 28 males and 87 females. Two participants did not complete the follow-up questionnaires so were excluded from these analyses. All participants gave informed consent and were paid for their participation. Ethical approval was obtained from King’s College London to complete the study and to share the data in the UK data Archive.

Procedure:

The study consisted of a screening stage, experimental session and a one week follow-up period. The experimental session comprised two consecutive phases (1) acquisition and (2) US devaluation. During acquisition, all participants underwent a Pavlovian discrimination fear conditioning paradigm and then participants were randomly allocated to one of three US devaluation groups. Questionnaires were administered in the screening stage and at one-week follow-up.

In the experimental session, subjects were instructed to pay attention to the computer screen and to try to work out the meaning of the CS+ and CS-. Trauma film stimuli were used as the US, a circle (0.5 inches in diameter) as the CS+ and a square (0.7 inches in length) as the CS-. At pre-determined points during the task, the CS+ and CS- appeared in the right hand corner of the screen for two seconds. The participant’s physiological and subjective responses to the CS+ and CS- were measured before and after each phase.

All participants took part in the acquisition phase. During acquisition, participants watched a series of six short film clips with introductory narratives and the CS+s embedded within them. The films contained real-life footage of humans and animals in distress. Each film contained an introductory voice-over which gave a narrative and context for the film. The CS+ was inserted into the films to signal the most distressing part of the film. The length of the film clips ranged from 76 to 150 seconds, with a mean length of 108.5 seconds (SD=33.09). After watching the six trauma films, participants viewed an intensive presentation phase in which the image and sound bite from the parts of the films previously paired with the CS+ (the worst moments) were presented again with the CS+. In this phase, the CS- was paired with neutral images. The CS+ was presented 10 times and the CS- presented 6 times during this phase. The US was displayed for 3 seconds.

In the US devaluation phase, participants were randomly allocated to one of three US devaluation groups: (1) update group (n=37): participants viewed the same films again but the introductory passage was elaborated to contain additional information about what happened to the protagonists in the films. (2) Habituation group (n=41): the trauma films with the introductory passages were viewed again by participants. (3) Neutral (n=37): participants viewed non-traumatic films of related content. Reinforced CSs were not presented in this phase.

In the week following the experimental phase, participants were asked to complete an intrusion diary to record any spontaneously occurring memories that they experienced related to the film clips and to complete the follow-up questionnaires.

Detailed documentation available in the thesis and paper listed below.

Observation unit:

Individual

Kind of data:

Numeric

Type of data:

Experimental data

Resource language:

English

Access and Administration

Data sourcing, processing and preparation:

Skin conductance response (SCR) Skin conductance response (SCR) signals were amplified with a BrainVision Quickamp with 22-bit A/D conversion and a resolution of 71.5 nV (range7150 mV) and digitised at a rate of 125 Hz. SCR was recorded through an auxiliary channel. Electrodermal activity (EDA) was measured as skin conductance response (SCR) in constant voltage technique using the GSR module produced by Brain Products, which applied a constant voltage of 0.5 V. Sintered silver-silver chloride (Ag-AgCl) cup electrodes were attached to volar surfaces of the medial phalanges of the second and third finger of the non-dominant hand, using MedCaT skin conductance electrode paste (0.05M NaCL saturation) as electrolyte. The electrodes were metal discs set in cylindrical plastic cases that were filled with electrode gel and fixed to the skin using double-sided adhesive circular collars (Boucsein et al., 2012). A bandpass filter of 0.0Hz to 2.00Hz was applied. EDA data were segmented into 2 second epochs (beginning 2 seconds pre-stimulus) and 8 second epochs (beginning post-stimulus). SCR amplitude was calculated as the difference between the mean SCR level for the 2 seconds preceding stimulus onset and the highest SCR value during the 8 seconds following stimulus onset, as has been done in recent studies (e.g. Pineles, Orr, & Orr, 2009). Statistical Analysis A two-tailed significant level of α=0.05 was used throughout analysis. For baseline characteristics, differences between the groups were analysed using Chi-squared analysis for categorical variables and a combination of one-way ANOVAs and their non-parametric equivalent for age, screening questionnaires, CS+ACQ (SCR and distress ratings) and SCR during the films and diary compliance. To compare the changes in SCR amplitudes and distress ratings across the experimental paradigm, individual difference scores (response following US devaluation minus response following acquisition) were calculated. Only non-reinforced trials of CS+ were included in the analysis in order to assess response to the CS+ alone separate from unconditioned responses to the trauma films. Kruskal-Wallis tests were used to compare the difference scores for the SCR amplitudes and distress ratings for each group and Mann-Whitney tests were used to follow up these findings by comparing each of the groups. A multivariate analysis of variance (MANOVA) was used to compare intrusion frequency, intrusion distress and IES-R scores for the three groups. Separate univariate ANOVAs were then conducted for each dependent variables and found significant differences between the groups on intrusion frequency and IES-R scores. Independent t-tests were then used to examine individual group differences. A multivariate analysis of covariance (MANCOVA) was used to analyse the relationship between an individual’s conditioned acquisition response, trait anxiety and maladaptive responses to memories of the trauma films and their intrusion frequency, intrusion distress and PTSD symptomatology.

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