Bornas, X., Gelabert, J. M., Llabres, J., Balle, M., & Tortella-Feliu, M. (2011). Slope of change throughout exposure treatment for flight phobia: the role of autonomic flexibility. Journal of Clinical Psychology, 67(6), 550-560. doi:10.1002/jclp.20780; 10.1002/jclp.20780
This study tested the hypothesis that flight-phobic patients experience change at different rates even when they are receiving identical treatment. Faster within-session rates of change (WSRC) were expected for patients who required fewer exposure sessions. The study also tested the theoretical role of autonomic flexibility on WSRC. High flexibility should be associated with faster rates of change. Thirty-seven flight-phobic patients were successfully treated with a computer-assisted fear of flying treatment. A significant negative correlation was found between total number of sessions and WSRC: The fewer sessions patients attended, the faster their rate of change was. The role of autonomic flexibility was partially supported: A significant correlation between heart rate variability and WSRC revealed that flexible patients improved faster than less-flexible patients. (c) 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1-11, 2011.
Xavier Bornas, Jordi Llabres, Miquel Tortella-Feliu, Miquel A. Fullana, Pedro Montoya, Ana Lopez, Miquel Noguera, Joan M. Gelabert, Vagally mediated heart rate variability and heart rate entropy as predictors of treatment outcome in flight phobia, Biological Psychology, Volume 76, Issue 3, October 2007, Pages 188-195, ISSN 0301-0511, DOI: 10.1016/j.biopsycho.2007.07.007.
In the present study a computer-assisted exposure-based treatment was applied to 54 flight phobics and the predictive role of vagally mediated heart rate (HR) variability (high frequency, 0.15-0.4 Hz band power) and heart rate entropy (HR time series sample entropy) on treatment outcome was investigated. Both physiological measures were taken under controlled breathing at 0.2 Hz and during exposure to a fearful sequence of audiovisual stimuli. Hierarchical regression analyses were conducted to assess the predictive power of these variables in these conditions on treatment self-report measures at the end of treatment and at 6 months follow-up, as well as on the behavioral treatment outcome (i.e. flying at the end of treatment). Regression models predicting significant amounts of outcome variance could be built only when HR entropy was added to the HR variability measure in a second step of the regression analyses. HR variability alone was not found to be a good predictor of neither self-reported nor behavioral treatment outcomes.
International Journal of Clinical and Health Psychology, 2006, 6, 549-563. Changes in heart rate variability of flight phobics during a paced breathing task and exposure to fearful stimuli. Xavier Bornas, Jordi Llabrés, Miquel Noguera, Ana María López, Miquel Tortella-Feliu, Miquel Ángel Fullana, Pedro Montoya, Joan Miquel Gelabert, and Irene Vila
The aim of this experiment was to explore changes in the vagally mediated heart rate variability (HRV) of flight phobics during exposure to feared stimuli. A paced breathing task was included to control for respiration effects. Sixty-one flight phobics (40 women) with a mean age of 39.07 years (SD = 11.24) participated in the study. The root mean of the squared successive interbeat intervals differences (RMSSD) was taken as the time domain measure of HRV. High frequency (HF: 0.15-0.4 Hz) and low frequency (LF: 0.04-0.15 Hz) band power was calculated on the ECG recordings obtained during free breathing baseline (BL), paced breathing (PB), and exposure (E) to fearful stimuli. Heart rate unexpectedly increased from BL to PB, and decreased from PB to E, while no differences were found between BL and E. No changes in the RMSSD were seen across conditions. HF band power increased, as expected, from BL to PB, and a significant decrease was found from PB to E. LF band power, as well as the LF/HF ratio, increased from BL to E. Discussion focuses on (a) the role of the parasympathetic and the sympathetic nervous systems in fear-related situations, and (b) the effects of paced breathing in preparing the system to cope with threat.
Xavier Bornas, Jordi Llabres, Miquel Noguera, Ana M Lopez, Joan Miquel Gelabert, Irene Vila, Fear induced complexity loss in the electrocardiogram of flight phobics: A multiscale entropy analysis, Biological Psychology, Volume 73, Issue 3, October 2006, Pages 272-279, ISSN 0301-0511, DOI: 10.1016/j.biopsycho.2006.05.004.
In this study we explored the changes in the variability and complexity of the electrocardiogram (ECG) of flight phobics (N = 61) and a matched non-phobic control group (N = 58) when they performed a paced breathing task and were exposed to flight related stimuli. Lower complexity/entropy values were expected in phobics as compared to controls. The phobic system complexity as well as the heart rate variability (HRV) were expected to be reduced by the exposure to fearful stimuli. The multiscale entropy (MSE) analysis revealed lower entropy values in phobics during paced breathing and exposure, and a complexity loss was observed in phobics during exposure to threatening situations. The expected HRV decreases were not found in this study. The discussion is focused on the distinction between variability and complexity measures of the cardiac output, and on the usefulness of the MSE analysis in the field of anxiety disorders.
Xavier Bornas, Jordi Llabres, Miquel Noguera, Ana M[feminine ordinal indicator] Lopez, Francesca Barcelo, Miquel Tortella-Feliu, Miquel Angel Fullana, Looking at the heart of low and high heart rate variability fearful flyers: self-reported anxiety when confronting feared stimuli, Biological Psychology, Volume 70, Issue 3, December 2005, Pages 182-187, ISSN 0301-0511, DOI: 10.1016/j.biopsycho.2005.01.002.
Previous research has shown that phobic subjects with low heart rate variability (HRV) are less able to inhibit an inappropriate response when confronted with threatening words compared to phobic subjects with high HRV [Johnsen, B.H., Thayer, J.F., Laberg, J.C., Wormnes, B., Raadal, M., Skaret, E., et al., 2003. Attentional and physiological characteristics of patients with dental anxiety. Journal of Anxiety Disorders, 17, 75-87]. The aim of this study was to evaluate changes in self-reported anxiety when low HRV and high HRV fearful flyers (N = 15) and a matched control group (N = 15) were exposed to flight-related pictures, flight-related sounds or both pictures and sounds. We hypothesized that sounds would be crucial to evoke fear. Also, low HRV fearful flyers were expected to report higher anxiety than high HRV fearful flyers assuming anxiety as their inappropriate response. Decreases on HRV measures were also predicted for a subgroup of phobic participants (N = 10) when confronted with the feared stimuli. Our data supported the hypothesis that sounds are crucial in this kind of phobia. Low HRV fearful flyers reported higher anxiety than high HRV fearful flyers in two out of three aversive conditions. The predicted HRV decreases were not found in this study. Results are discussed in the context of avoidance of exposure-based treatments.
Anxiety, Stress & Coping. Volume 17, Issue 4, 2004, 331-339. Self-implication and heart rate variability during simulated exposure to flight-related stimuli. DOI:10.1080/10615800512331328777. Xavier Bornas, Jordi Llabrés, Miquel Noguera, Ana M. López, Francesca Barceló, Miquel Tortella-Feliu & Miquel Àngel Fullana
In the present study, the relationship between self-implication during simulated exposure to feared stimuli and Heart Rate Variability (HRV) was explored within the framework of the dynamical systems model of emotion regulation proposed by Thayer and Lane (Thayer, J.F., and Lane, R.D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 201–216.). An analogue sample of flight phobics (n=15) and a matched non-phobic control group (n=15) were presented with flight-related pictures, flight-related sounds or flight-related pictures and sounds. Significant differences on self-implication during exposure to flight-related sounds were found between low and high HRV fearful flyers, the former being more self-implied. However, the expected HRV decreases in the phobic participants exposed to feared stimuli were not found. These results emphasize the need to distinguish between high and low HRV fearful flyers in order to make a better use of the simulated exposure treatments.