Peripheral physiological changes during emotion

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Chapter 1 endnote 26, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

Where emotions and the autonomic nervous system are concerned, four significant meta-analyses have been conducted in the last two decades, the largest of which covered more than 220 physiology studies and nearly 22,000 test subjects. None of these four meta-analyses found consistent and specific emotion fingerprints in the body. Instead, the body’s orchestra of internal organs can play many different symphonies during happiness, fear, and the rest.

In 2000, a meta-analysis covering 22 studies concluded that emotions such as anger, sadness, fear, and disgust did not have distinct fingerprints in the autonomic nervous system.[1] The measurements of each variable (e.g., heart rate) varied so greatly within an emotion from experiment to experiment—sometimes increasing with the emotion, sometimes decreasing—that it did not make statistical sense to average them. For example, on average, studies of anger reported greater increases in both diastolic blood pressure (DBP) and heart rate relative to studies of fear, but these factors varied so greatly from study to study that these averages are meaningless. Also, in general, DBP increases when people feel threatened, and heart rate tends to increase more when people feel motivated to meet a challenge, offering alternative explanations for these findings.[2][3] No other averages delivered clear and distinguishing patterns that could diagnose the presence or absence of each emotion.[4] At best, measurements of the autonomic nervous system distinguished patterns for pleasant vs. unpleasant feelings.

In 2004, a second meta-analysis assessed the consistency and specificity of physiological changes in 15 studies of anger and fear, eight of which appeared in the first meta-analysis.[5] Substantial variation (i.e., little evidence of consistency) was observed for all physiological changes. On average, studies of fear and anger differed in a number of physiological changes, including respiration rate,total peripheral resistance, cardiac output, facial temperature, and DBP, but not heart rate. Nevertheless, the author focused on the averages—but ignored the substantial variation around those averages—and concluded that he had found evidence for autonomic fingerprints for anger and fear.

In 2011, a third, larger meta-analysis covered over 100 studies.[6] (Technically, this meta-analysis included 687 studies, but only 109 of them were physiology studies. The total number of subjects was about 50,000.) This meta-analysis reported that emotions can be effectively induced in the lab, and that bodily changes can be measured effectively in these experiments, but the changes do not conform to any specific, consistent, or predicted patterns. Even so, the authors concluded that their data supports the classical view, and the paper is often cited for that support. For this to be true, however, one must demonstrate both consistency and specificity: that a given emotion, such as happiness, consistently produces the same pattern of response, and is the only emotion to produce that pattern. Their meta-analysis showed, however, that the same emotion produced a variety of bodily responses. Their conclusions are a classic example of a preconceived notion—belief in emotion fingerprints—influencing the experimenters’ interpretation of the data.[7]

Members of my lab, led by my former graduate student Erika Siegel, conducted a fourth meta-analysis in 2013, the largest to date, including 223 physiology studies and nearly 22,000 test subjects.[8] We sampled a broader range of experiments measuring autonomic physiology than the first meta-analysis published in 2000, but the findings were basically the same: There was so much variation in physiological responses for each emotion across different studies that it was impossible to detect any emotion-specific fingerprints.

This degree of variation should not be surprising. The autonomic nervous system, which controls your body's organs, did not evolve for you to have emotions: it evolved for you to move your body. Effective action is tied to the context and will vary as you experience emotions in different situations, depending on which actions are required.

See also

Notes on the Notes

  1. Cacioppo, John T., Gary G. Berntson, Jeff T. Larsen, Kirsten M. Poehlmann, and Tiffany A. Ito. 2000. "The psychophysiology of emotion." In Handbook of Emotions, 2nd edition, edited by Michael Lewis and Jeannette M. Haviland-Jones, 173-191. New York: Guilford Press.
  2. Blascovich, Jim, and Wendy Berry Mendes. 2010. "Social psychophysiology and embodiment." In The Handbook of Social Psychology, 5th edition,  edited by Susan. T. Fiske, Daniel T. Gilbert, and Gardner Lindzey, 194-227. New York, NY: John Wiley & Sons.
  3. Quigley, Karen. S., Lisa Feldman Barrett, and S. Weinstein. 2002.  "Cardiovascular patterns associated with threat and challenge appraisals: Individual responses across time." Psychophysiology 39: 1-11.
  4. Quigley, Karen S., and Lisa Feldman Barrett. 2014. "Is there consistency and specificity of autonomic changes during emotional episodes? Guidance from the conceptual act theory and psychophysiology." Biological Psychology 98: 82-94.    
  5. Stemmler, Gerhard. 2004. "Physiological processes during emotion." In The Regulation of Emotion, edited by Pierre Philippot and Robert S. Feldman, 33-70. Mahwah, New Jersey: Lawrence Erlbaum & Associates.
  6. Lench, Heather C., Sarah A. Flores, and Shane W. Bench. 2011. "Discrete emotions predict changes in cognition, judgment, experience, behavior, and physiology: a meta-analysis of experimental emotion elicitations." Psychological Bulletin 137 (5): 834-855. 
  7. Lindquist, Kristen A., Erika H. Siegel, Karen S. Quigley, and Lisa Feldman Barrett. 2013. "The hundred-year emotion war: are emotions natural kinds or psychological constructions? Comment on Lench, Flores, and Bench (2011)." Psychological Bulletin 139 (1): 255-263.
  8. Siegel, E. H., Sands, M. K., Condon, P., Chang, Y., Dy, J., Quigley, K. S., & Barrett, L. F. Under review. "Emotion fingerprints or emotion populations? A meta-analytic investigation of autonomic features of emotion categories."