Abstract
The pupil diameter (PD), controlled by the autonomic nervous system, seems to provide a strong indication of affective arousal, as found by previous research, but it has not been investigated fully yet. In this study, new approaches based on monitoring and processing the PD signal for off-line and on-line “relaxation” vs. “stress” differentiation are proposed. For the off-line approach, wavelet denoising, Kalman filtering, data normalization, and feature extraction are sequentially utilized. For the on-line approach, a hard threshold, a moving average window and three stress detection steps are implemented. In order to use only the most reliable data, two types of data selection methods (paired t test based on galvanic skin response (GSR) data and subject self-evaluation) are applied, achieving average classification accuracies up to 86.43 and 87.20% for off-line and 72.30 and 73.55% for on-line algorithms, with each set of selected data, respectively. The GSR was also monitored and processed in our experiments for comparison purposes, with the highest classification rate achieved being only 63.57% (based on the off-line processing algorithm). The overall results show that the PD signal is more effective and robust for differentiating “relaxation” vs. “stress,” in comparison with the traditionally used GSR signal.
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Andreassi, J. L. Psychophysiology: Human Behavior & Physiological Response. Mahwah, NJ: Lawrence Erlbaum Associates, 2007.
Andren, J., and P. Funk. A case-based approach using behavioural biometrics to determine a user’s stress level. In: ICCBR Workshops, 2005, pp. 9–17.
Beatty, J., and B. Lucero-Wagoner. Handbook of Psychophysiology. Cambridge: Cambridge University Press, 2000.
Begum, S., M. U. Ahmed, P. Funk, and N. Xiong. Using calibration and fuzzification of cases for improved diagnosis and treatment of stress. In: 8th European Conference on Case-Based Reasoning Workshop Proceedings, edited by M. Minor, 2006, pp. 113–122.
Cano-Vindel, A., J. J. Miguel-Tobal, H. Gonzalez-Ordi, and I. Iruarrizaga-Diez. Hyperventilation and anxiety experience. Anxiety Stress 13(2–3):291–302, 2007.
Fellous, M., and M. A. Arbib. Who Needs Emotions? The Brain Meets the Robot. New York: Oxford University Press, 2005.
Field, A. Discovering Statistics Using SPSS (3rd ed.). New York: Sage, 2009.
Gao, Y., A. Barreto, and M. Adjouadi. Monitoring and Processing of the Pupil Diameter Signal for Affective Assessment of a Computer User. Lecture Notes in Computer Science (LNCS). LNCS 5610, 2009, pp. 49–58.
Gao, Y., A. Barreto, and M. Adjouadi. Affective assessment of a computer user through the processing of the pupil diameter signal. In: Innovations in Computing Sciences and Software Engineering, edited by T. Sobh, and K. Elleithy. New York: Springer, 2010, pp. 189–194.
Granholm, E., and S. R. Steinhauer. Introduction: Pupillometric measures of cognitive and emotional processing. Int. J. Psychophysiol. 52:1–6, 2004.
Grewal, M. S., and A. P. Andrews. Kalman Filtering: Theory and Practice Using MATLAB (3rd ed.). Hoboken, NJ: Wiley-IEEE Press, 2008.
Healey, J. Wearable and Automotive Systems for Affect Recognition from Physiology. Ph.D. dissertation, MIT Media Lab, 2000.
Healey, J. A., and R. W. Picard. Detecting stress during real-world driving tasks using physiological sensors. IEEE Trans. Intell. Transp. Syst. 6(2):156–166, 2005.
Hjemdahl, P., U. Freyschuss, A. Juhlin-Dannfelt, and B. Linde. Differentiated sympathetic activation during mental stress evoked by the Stroop test. Acta Physiol. Scand. Suppl. 527:25–29, 1984.
Holmqvist, K., M. Nystrom, R. Andersson, R. Dewhurst, H. Jarodzka, and J. Weijer. Eye Tracking: A Comprehensive Guide to Methods and Measures. Oxford: Oxford University Press, 2011.
Klingner, J. The pupillometric precision of a remote video eye tracker. In: Proceedings of the 2010 Symposium on Eye-Tracking Research Applications (ETRA ‘10). New York: ACM, 2010, pp. 259–262.
Lim, C. L., C. Rennie, R. J. Barry, H. Bahramali, I. Lazzaro, and B. Manor. Decomposing skin conductance into tonic and phasic components. Int. J. Psychophysiol. 24(2):97–109, 1997.
Martini, F. H., and J. L. Nath. Fundamentals of Anatomy & Physiology (8th ed.). San Francisco: Benjamin Cummings, 2008.
Morgante, J. D., R. Zolfaghari, and S. P. Johnson. A critical test of temporal and spatial accuracy of the Tobii T60XL eye tracker. Infancy 17:9–32, 2012.
Partala, T., and V. Surakka. Pupil size variation as an indication of affective processing. Int. J. Hum.–Comput. Stud. 59:185–198, 2003.
Picard, W., and J. A. Healey. Wearable and automotive systems for affect recognition from physiology. Technical report, MIT, 2000.
Raymond, J. C. Dictionary of Psychology. New York: Routledge, 1999.
Shi, Y., N. Ruiz, R. Taib, E. Choi, and F. Chen. Galvanic skin response as an index of cognitive load. In: Proceeding of Computer–Human Interaction conference on Human Factors in Computing System, 2007, pp. 2651–2656.
Siegle, G. J., S. R. Steinhauer, and M. E. Thase. Pupillary assessment and computational modeling of early and sustained processing on the Stroop task in depression. Int. J. Psychophysiol. 52:63–76, 2004.
Sierra, A. S., C. S. Ávila, J. G. Casanova, and G. B. Pozo. A stress-detection system based on physiological signals and fuzzy logic. IEEE Trans. Ind. Electron. 58(10):4857–4865, 2011.
Sierra, A. S., C. S. Ávila, A. Mendaza-Ormaza, and J. G. Casanova. An approach to hand biometrics in mobile devices. SIViP 5(4):469–475, 2011.
Smith, S. W. The Scientist and Engineer’s Guide to Digital Signal Processing. San Diego, CA: California Technical Publishing, 1997.
Steinhauer, S. R., G. J. Siegle, R. Condray, and M. Pless. Sympathetic and parasympathetic innervation of pupillary dilation during sustained processing. Int. J. Psychophysiol. 52:77–86, 2004.
Stern, R. M., W. J. Ray, and K. S. Quigley. Psychophysiological Recording. Oxford: Oxford University Press, 2000.
Stroop, J. R. Studies of interference in serial verbal reactions. J. Exp. Psychol. 18:643–662, 1935.
Sun, F., C. Kuo, H. Cheng, S. Buthpitiya, P. Collins, and M. L. Griss. Activity-Aware Mental Stress Detection Using Physiological Sensors. Silicon Valley Campus, Paper 23, 2010.
Tognetti, S., M. Garbarino, M. Matteucci, and A. Bonarini. The affective triad: stimuli, questionnaires, and measurements. In: Proceeding of ACII’11, Vol. II, 2011, pp. 101–110.
Tourangeau, R., L. J. Rips, and K. A. Rasinski. The Psychology of Survey Response. Cambridge: Cambridge University Press, 2000.
Tsai, S. S. Power Transformer Partial Discharge (PD) Acoustic Signal Detection Using Fiber Sensors and Wavelet Analysis, Modeling, and Simulation. Master’s Thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA, 2002.
Tulen, J., H. P. Moleman, H. G. Steenis, and F. Boomsma. Characterization of stress reactions to the Stroop color word test. Pharmacol. Biochem. Behav. 32(1):9–15, 1989.
University of California-Irvine. Short-term stress can affect learning and memory. ScienceDaily. March, 11, 2008.
Verney, S. P., E. Granholm, and S. P. Marshall. Pupillary responses on the visual backward masking task reflect general cognitive ability. Int. J. Psychophysiol. 52:23–36, 2004.
Weigle, C., and D. C. Banks. Analysis of eye-tracking experiments performed on a Tobii T60. In: Proceedings of the SPIE6809, Visualization and Data Analysis, January, 2008.
Zhai, J., and A. Barreto. Stress detection in computer users through noninvasive monitoring of physiological signals. Biomed. Sci. Instrum. 42:495–500, 2006.
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This work was sponsored by NSF grants HRD-0833093 and CNS-0959985.
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Associate Editor Leonidas D Iasemidis oversaw the review of this article.
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Ren, P., Barreto, A., Huang, J. et al. Off-line and On-line Stress Detection Through Processing of the Pupil Diameter Signal. Ann Biomed Eng 42, 162–176 (2014). https://doi.org/10.1007/s10439-013-0880-9
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DOI: https://doi.org/10.1007/s10439-013-0880-9