, Volume 11, Issue 3, pp 297–308 | Cite as

The Role of Emotion Regulation in Moral Judgment

  • Chelsea HelionEmail author
  • Kevin N. Ochsner
Original Paper


Moral judgment has typically been characterized as a conflict between emotion and reason. In recent years, a central concern has been determining which process is the chief contributor to moral behavior. While classic moral theorists claimed that moral evaluations stem from consciously controlled cognitive processes, recent research indicates that affective processes may be driving moral behavior. Here, we propose a new way of thinking about emotion within the context of moral judgment, one in which affect is generated and transformed by both automatic and controlled processes, and moral evaluations are shifted accordingly. We begin with a review of how existing theories in psychology and neuroscience address the interaction between emotion and cognition, and how these theories may inform the study of moral judgment. We then describe how brain regions involved in both affective processing and moral judgment overlap and may make distinct contributions to the moral evaluation process. Finally, we discuss how this way of thinking about emotion can be reconciled with current theories in moral psychology before mapping out future directions in the study of moral behavior.


Moral judgment Emotion regulation 



Completion of the manuscript was supported by grants AG043463 from NIA and HD069178 from NICHD awarded to K. Ochsner, and grant F32HD081960 from NICHD awarded to C. Helion.


  1. 1.
    Helion, C., and D.A. Pizarro. 2015. Beyond dual-processes: the interplay of reason and emotion in moral judgment. In Springer Handbook for Neuroethics, eds. N. Levy, and J. Clausen, 109–125. Dordecht: Springer Netherlands.Google Scholar
  2. 2.
    Frank, R.H. 1988. Passions within reason: the strategic role of the emotions. WW Norton & Company: New York, NY.Google Scholar
  3. 3.
    Keltner, D., and J.S. Lerner. 2010. Emotion. In The handbook of social psychology, 5th edn, eds. D.T. Gilbert, S.T. Fiske, and G. Lindsay, 312–347. New York: McGraw Hill.Google Scholar
  4. 4.
    Ochsner, K.N., and L. Feldman-Barrett. 2001. A multiprocess perspective on the neuroscience of emotion. In Emotion: Current Issues and Future Directions, eds. T.J. Mayne, and G. Bonnano, 38–81. Guilford Press: New York.Google Scholar
  5. 5.
    Ochsner, K.N., J.A. Silvers, and J.T. Buhle. 2012. Functional imaging studies of emotion regulation: a synthetic review and evolving model of the cognitive control of emotion. Annals of the New York Academy of Sciences 1251(1): E1–E24.CrossRefGoogle Scholar
  6. 6.
    Loewenstein, G., and J.S. Lerner. 2003. The role of affect in decision making. In Handbook of affective sciences, eds. R.J. Davidson, K.R. Scherer, and H.H. Goldsmith, 619–642. New York: Oxford University Press.Google Scholar
  7. 7.
    Kohlberg, L. 1963. Moral development and identification. In Child psychology: 62nd yearbook of the National Society for the study of education, ed. H. Stevenson, 11–33. Chicago: University of Chicago Press.Google Scholar
  8. 8.
    Piaget, J. 1932. The moral judgment of the child. New York: Harcourt, Brace Jovanovich.Google Scholar
  9. 9.
    Greene, J., and J. Haidt. 2002. How (and where) does moral judgment work? Trends in Cognitive Sciences 6(12): 517–523.CrossRefGoogle Scholar
  10. 10.
    Greene, J.D., R.B. Sommerville, L.E. Nystrom, J.M. Darley, and J.D. Cohen. 2001. An fMRI investigation of emotional engagement in moral judgment. Science 293(5537): 2105–2108.CrossRefGoogle Scholar
  11. 11.
    Thomson, J.J. 1976. Killing, letting die, and the trolley problem. The Monist 59(2): 204–217.CrossRefGoogle Scholar
  12. 12.
    Haidt, J. 2001. The emotional dog and its rational tail: a social intuitionist approach to moral judgment. Psychological Review. 108: 814–834.CrossRefGoogle Scholar
  13. 13.
    Ochsner, K.N. 2014. What is the role of control in emotional life? In Social neuroscience and emotion, ed. M. Gazzaniga, 719–730. MIT Press: Cambridge.Google Scholar
  14. 14.
    Knobe, J. 2003. Intentional action and side effects in ordinary language. Analysis 63(279): 190–194.CrossRefGoogle Scholar
  15. 15.
    Schnall, S., Haidt, J., Clore, G. L., & Jordan, A. H. (2008). Disgust as embodied moral judgment. Personality and Social Psychology Bulletin (34), 8: 1096–1109.Google Scholar
  16. 16.
    Nisbett, R.E., and T.D. Wilson. 1977. Telling more than we can know: verbal reports on mental processes. Psychological Review 84(3): 231–259.Google Scholar
  17. 17.
    Schwarz, N. 2012. Feelings-as-information theory. In Handbook of theories of social psychology, eds. P.A.M. Van Lange, A. Kruglanski, and E.T. Higgins, 289–308. Thousand Oaks, CA: Sage.Google Scholar
  18. 18.
    Simon, H.A. 1967. Motivational and emotional controls of cognition. Psychological Review 74(1): 29–39.CrossRefGoogle Scholar
  19. 19.
    Monin, B., D.A. Pizarro, and J.S. Beer. 2007. Deciding versus reacting: conceptions of moral judgment and the reason-affect debate. Review of General Psychology 11(2): 99–111.Google Scholar
  20. 20.
    Crockett, M.J. 2013. Models of morality. Trends in Cognitive Sciences 17(8): 363–366.CrossRefGoogle Scholar
  21. 21.
    Cushman, F. 2013. Action, outcome, and value a dual-system framework for morality. Personality and Social Psychology Review 17(3): 273–292.CrossRefGoogle Scholar
  22. 22.
    Huebner, B. 2015. Do emotions play a constitutive role in moral cognition? Topoi 34(2): 427–440.CrossRefGoogle Scholar
  23. 23.
    Daw, N.D., Y. Niv, and P. Dayan. 2005. Uncertainty-based competition between prefrontal and dorsolateral striatal systems for behavioral control. Nature Neuroscience 8(12): 1704–1711.CrossRefGoogle Scholar
  24. 24.
    Huebner, B., S. Dwyer, and M. Hauser. 2009. The role of emotion in moral psychology. Trends in Cognitive Sciences 13(1): 1–6.CrossRefGoogle Scholar
  25. 25.
    Gross, J.J., and R.A. Thompson. 2007. Emotion regulation: conceptual foundations. In the Handbook of emotion regulation, ed. J.J. Gross, 3–24. New York: Guilford PressGoogle Scholar
  26. 26.
    Ochsner, K.N., and J.J. Gross. 2014. The neural bases of emotion and emotion regulation: a valuation perspective. In The handbook of emotion regulation, Second edn, eds. J.J. Gross, and R. Thompson, 23–42. New York: Guilford Press.Google Scholar
  27. 27.
    Bargh, J.A., S. Chaiken, R. Govender, and F. Pratto. 1992. The generality of the automatic attitude activation effect. Journal of Personality and Social Psychology 62(6): 893–912.Google Scholar
  28. 28.
    Lazarus, R.S. 1991. Emotion and adaptation. New York: Oxford University Press.Google Scholar
  29. 29.
    Todorov, A., and J.S. Uleman. 2003. The efficiency of binding spontaneous trait inferences to actors’ faces. Journal of Experimental Social Psychology 39: 549–562.CrossRefGoogle Scholar
  30. 30.
    Knutson, B., and J.C. Cooper. 2005. Functional magnetic resonance imaging of reward prediction. Current Opinion in Neurology 18(4): 411–417.CrossRefGoogle Scholar
  31. 31.
    Todorov, A., and J.S. Uleman. 2004. The person reference process in spontaneous trait inferences. Journal of Personality and Social Psychology 87(4): 482–493.CrossRefGoogle Scholar
  32. 32.
    LaBar, K.S., and R. Cabeza. 2006. Cognitive neuroscience of emotional memory. Nature Reviews Neuroscience 7(1): 54–64.CrossRefGoogle Scholar
  33. 33.
    Ochsner, K.N., and J.J. Gross. 2005. The cognitive control of emotion. Trends in Cognitive Sciences 9(5): 242–249.CrossRefGoogle Scholar
  34. 34.
    Ochsner, K.N., R.R. Ray, B. Hughes, K. McRae, J.C. Cooper, J. Weber, J.D.E. Gabrieli, and J.J. Gross. 2009. Bottom-up and top-down processes in emotion generation common and distinct neural mechanisms. Psychological Science 20(11): 1322–1331.CrossRefGoogle Scholar
  35. 35.
    Satpute, A.B., J. Shu, J. Weber, M. Roy, and K. Ochsner. 2013. The functional neural architecture of self-reports of affective experience. Biological Psychiatry 73(7): 631–638.CrossRefGoogle Scholar
  36. 36.
    Moors, A., P.C. Ellsworth, K.R. Scherer, and N.H. Frijda. 2013. Appraisal theories of emotion: state of the art and future development. Emotion Review 5(2): 119–124.CrossRefGoogle Scholar
  37. 37.
    LeDoux, J.E. 2003. Synaptic self: How our brains become who we are. New York, NY: Penguin.Google Scholar
  38. 38.
    Clore, G.L., and J.R. Huntsinger. 2007. How emotions inform judgment and regulate thought. Trends in Cognitive Sciences 11(9): 393–399.CrossRefGoogle Scholar
  39. 39.
    Ochsner, K.N., R.D. Ray, J.C. Cooper, E.R. Robertson, S. Chopra, J.D. Gabrieli, and J.J. Gross. 2004. For better or for worse: neural systems supporting the cognitive down-and up-regulation of negative emotion. NeuroImage 23(2): 483–499.CrossRefGoogle Scholar
  40. 40.
    Ray, R.D., K.N. Ochsner, J.C. Cooper, E.R. Robertson, J.D. Gabrieli, and J.J. Gross. 2005. Individual differences in trait rumination and the neural systems supporting cognitive reappraisal. Cognitive, Affective, & Behavioral Neuroscience 5(2): 156–168.CrossRefGoogle Scholar
  41. 41.
    Greene, J.D. 2009. Dual-process morality and the personal/impersonal distinction: a reply to McGuire, Langdon, Coltheart, and Mackenzie. Journal of Experimental Social Psychology 45(3): 581–584.CrossRefGoogle Scholar
  42. 42.
    Shenhav, A., and J.D. Greene. 2010. Moral judgments recruit domain-general valuation mechanisms to integrate representations of probability and magnitude. Neuron 7: 667–677.CrossRefGoogle Scholar
  43. 43.
    Cunningham, W.A., and P.D. Zelazo. 2007. Attitudes and evaluations: a social cognitive neuroscience perspective. Trends in Cognitive Sciences 11(3): 97–104.CrossRefGoogle Scholar
  44. 44.
    Feinberg, M., O. Antonenko, R. Willer, E.J. Horberg, and O.P. John. 2014. Gut check: reappraisal of disgust helps explain liberal–conservative differences on issues of purity. Emotion 14(3): 513–521.Google Scholar
  45. 45.
    Forgas, J.P. 2002. Toward understanding the role of affect in social thinking and behavior. Psychological Inquiry 13(1): 90–102.CrossRefGoogle Scholar
  46. 46.
    Pizarro, D., Y. Inbar, and C. Helion. 2011. On disgust and moral judgment. Emotion Review 3(3): 267–268.CrossRefGoogle Scholar
  47. 47.
    Pond, R.S. Jr., C.N. DeWall, N.M. Lambert, T. Deckman, I.M. Bonser, and F.D. Fincham. 2012. Repulsed by violence: Disgust sensitivity buffers trait, behavioral, and daily aggression. Journal of personality and social psychology 102(1): 175–188.Google Scholar
  48. 48.
    Inbar, Y., D.A. Pizarro, and P. Bloom. 2009b. Conservatives are more easily disgusted. Cognition & Emotion 23: 714–725.CrossRefGoogle Scholar
  49. 49.
    Inbar, Y., D.A. Pizarro, J. Knobe, and P. Bloom. 2009a. Disgust sensitivity predicts intuitive disapproval of gays. Emotion 9: 435–439.CrossRefGoogle Scholar
  50. 50.
    Van Dillen, L.F., R.C. van der Wal, and K. van den Bos. 2012. On the role of attention and emotion in morality attentional control modulates unrelated disgust in moral judgments. Personality and Social Psychology Bulletin 38(9): 1222–1231.CrossRefGoogle Scholar
  51. 51.
    Bonanno, G.A., S. Galea, A. Bucciarelli, and D. Vlahov. 2007. Psychological resilience after disaster: New York City in the aftermath of the September 11th terrorist attack. Psychological Science 17(3): 181–186.CrossRefGoogle Scholar
  52. 52.
    Mehl, M.R., and J.W. Pennebaker. 2003. The social dynamics of cultural upheaval: social interactions surrounding September 11th, 2001. Psychological Science 14(6): 579–585.CrossRefGoogle Scholar
  53. 53.
    Parkinson, C., W. Sinnott-Armstrong, P. Koralus, A. Mendelovici, V. McGeer, and T. Wheatley. 2011. Is morality unified? Evidence that distinct neural systems underlie moral judgments of harm, dishonesty, and disgust. Cognitive Neuroscience, Journal of 23(10): 3162–3180.CrossRefGoogle Scholar
  54. 54.
    Young, L., and J. Dungan. 2012. Where in the brain is morality? Everywhere and maybe nowhere. Social Neuroscience 7(1): 1–10.CrossRefGoogle Scholar
  55. 55.
    Davis, M., and P.J. Whalen. 2001. The amygdala: vigilance and emotion. Molecular Psychiatry 2001(6): 13–34.Google Scholar
  56. 56.
    Sander, D., J. Grafman, and T. Zalla. 2003. The human amygdala: an evolved system for relevance detection. Reviews in the Neurosciences 14(4): 303–316.CrossRefGoogle Scholar
  57. 57.
    Luo, Q., M. Nakic, T. Wheatley, R. Richell, A. Martin, and R.J.R. Blair. 2006. The neural basis of implicit moral attitude—an IAT study using event-related fMRI. NeuroImage 30(4): 1449–1457.CrossRefGoogle Scholar
  58. 58.
    Cunningham, W.A., and T. Brosch. 2012. Motivational salience amygdala tuning from traits, needs, values, and goals. Current Directions in Psychological Science 21(1): 54–59.CrossRefGoogle Scholar
  59. 59.
    Berthoz, S., J. Grezes, J.L. Armony, R.E. Passingham, and R.J. Dolan. 2006. Affective response to one’s own moral violations. NeuroImage 31(2): 945–950.CrossRefGoogle Scholar
  60. 60.
    Nader, K., G.E. Schafe, and J.E. LeDoux. 2000. Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval. Nature 406: 722–726.Google Scholar
  61. 61.
    Treadway, M.T., J.W. Buckholtz, J.W. Martin, K. Jan, C.L. Asplund, M.R. Ginther, O.D. Jones, and R. Marois. 2014. Corticolimbic gating of emotion-driven punishment. Nature Neuroscience 17(9): 1270–1275. doi: 10.1038/nn.3781.CrossRefGoogle Scholar
  62. 62.
    Craig, A.D. 2009. How do you feel–now? The anterior insula and human awareness. Nature Reviews Neuroscience 10(1): 59–70.CrossRefGoogle Scholar
  63. 63.
    Zaki, J., J.I. Davis, and K.N. Ochsner. 2012. Overlapping activity in anterior insula during interoception and emotional experience. NeuroImage 62(1): 493–499.CrossRefGoogle Scholar
  64. 64.
    Sanfey, A.G., J.K. Rilling, J.A. Aronson, L.E. Nystrom, and J.D. Cohen. 2003. The neural basis of economic decision-making in the ultimatum game. Science 300: 1755–1758.CrossRefGoogle Scholar
  65. 65.
    Calder, A.J., J. Keane, F. Manes, N. Antoun, and A.W. Young. 2000. Impaired recognition and experience of disgust following brain injury. Nature Neuroscience 3(11): 1077–1078.CrossRefGoogle Scholar
  66. 66.
    Chapman, H.A., and A.K. Anderson. 2012. Understanding disgust. Annals of the New York Academy of Sciences 1251(1): 62–76.CrossRefGoogle Scholar
  67. 67.
    Lamm, C., C.D. Batson, and J. Decety. 2007. The neural substrate of human empathy: effects of perspective-taking and cognitive appraisal. Journal of Cognitive Neuroscience 19(1): 42–58.CrossRefGoogle Scholar
  68. 68.
    Paulus, M.P., C. Rogalsky, A. Simmons, J.S. Feinstein, and M.B. Stein. 2003. Increased activation in the right insula during decision making is related to harm avoidance and neuroticism. NeuroImage 19: 1439–1448.CrossRefGoogle Scholar
  69. 69.
    Calder, A.J., A.D. Lawrence, and A.W. Young. 2001. Neuropsychology of fear and loathing. Nature Reviews Neuroscience 2(5): 352–363.CrossRefGoogle Scholar
  70. 70.
    Van Veen, V., M.K. Krug, J.W. Schooler, and C.S. Carter. 2009. Neural activity predicts attitude change in cognitive dissonance. Nature Neuroscience 12(11): 1469–1474.CrossRefGoogle Scholar
  71. 71.
    Greene, J.D., L.E. Nystrom, A.D. Engell, J.M. Darley, and J.D. Cohen. 2004. The neural bases of cognitive conflict and control in moral judgment. Neuron 44(2): 389–400.CrossRefGoogle Scholar
  72. 72.
    Amodio, D.M. 2014. The neuroscience of prejudice and stereotyping. Nature Reviews Neuroscience 15: 670–682.CrossRefGoogle Scholar
  73. 73.
    Spunt, R.P., A.B. Satpute, and M.D. Lieberman. 2011. Identifying the what, why, and how of an observed action: an fMRI study of mentalizing and mechanizing during action observation. Journal of Cognitive Neuroscience 23(1): 63–74.CrossRefGoogle Scholar
  74. 74.
    Young, L., and R. Saxe. 2008. The neural basis of belief encoding and integration in moral judgment. NeuroImage 40(4): 1912–1920.CrossRefGoogle Scholar
  75. 75.
    Cunningham, W.A., I.R. Johnsen, and A.S. Waggoner. 2011. Orbitofrontal cortex provides cross-modal valuation of self-generated stimuli. Social Cognitive and Affective Neuroscience 6(3): 286–293.CrossRefGoogle Scholar
  76. 76.
    Cushman, F. 2014. The neural basis of morality: not just where, but when. Brain 137(4): 974–975.CrossRefGoogle Scholar
  77. 77.
    Young, L., A. Bechara, D. Tranel, H. Damasio, M. Hauser, and A. Damasio. 2010. Damage to ventromedial prefrontal cortex impairs judgment of harmful intent. Neuron 65(6): 845–851.CrossRefGoogle Scholar
  78. 78.
    Wendelken, C., S.A. Bunge, and C.S. Carter. 2008. Maintaining structured information: an investigation into functions of parietal and lateral prefrontal cortices. Neuropsychologia 46(2): 665–678.CrossRefGoogle Scholar
  79. 79.
    Browning, M., E.A. Holmes, S.E. Murphy, G.M. Goodwin, and C.J. Harmer. 2010. Lateral prefrontal cortex mediates the cognitive modification of attentional bias. Biological Psychiatry 67(10): 919–925.CrossRefGoogle Scholar
  80. 80.
    Ridderinkhof, K.R., M. Ullsperger, E.A. Crone, and S. Nieuwenhuis. 2004. The role of the medial frontal cortex in cognitive control. Science 306(5695): 443–447.CrossRefGoogle Scholar
  81. 81.
    Jarcho, J.M., E.T. Berkman, and M.D. Lieberman. 2011. The neural basis of rationalization: cognitive dissonance reduction during decision-making. Social Cognitive and Affective Neuroscience 6(4): 460–467.CrossRefGoogle Scholar
  82. 82.
    Rilling, J.K., and A.G. Sanfey. 2011. The neuroscience of social decision-making. Annual Review of Psychology 62: 23–48.CrossRefGoogle Scholar
  83. 83.
    Kringelbach, M.L. 2005. The human orbitofrontal cortex: linking reward to hedonic experience. Nature Reviews Neuroscience 6(9): 691–702.Google Scholar
  84. 84.
    Beer, J.S., O.P. John, D. Scabini, and R.T. Knight. 2006. Orbitofrontal cortex and social behavior: integrating self-monitoring and emotion-cognition interactions. Journal of Cognitive Neuroscience 18(6): 871–879.CrossRefGoogle Scholar
  85. 85.
    Lieberman, M.D., N.I. Eisenberger, M.J. Crockett, S.M. Tom, J.H. Pfeifer, and B.M. Way. 2007. Putting feelings into words affect labeling disrupts amygdala activity in response to affective stimuli. Psychological Science 18(5): 421–428.CrossRefGoogle Scholar
  86. 86.
    Decety, J., K.J. Michalska, and K.D. Kinzler. 2012. The contribution of emotion and cognition to moral sensitivity: a neurodevelopmental study. Cerebral Cortex 22(1): 209–220.CrossRefGoogle Scholar
  87. 87.
    Blair, R.J.R. 2007. The amygdala and ventromedial prefrontal cortex in morality and psychopathy. Trends in Cognitive Sciences 11(9): 387–392.CrossRefGoogle Scholar
  88. 88.
    Moll, J., R. de Oliveira - Souza, P.J. Eslinger, I.E. Bramati, J. Mourao - Miranda, P.A. Andreiuolo, et al. 2002. The neural correlates of moral sensitivity: a functional magnetic resonance imaging investigation of basic and moral emotions. Journal of Neuroscience 22: 2730–2736.CrossRefGoogle Scholar
  89. 89.
    Teper, R., A.M. Tullett, E. Page-Gould, and M. Inzlicht. 2015. Errors in moral forecasting perceptions of affect shape the gap between moral behaviors and moral forecasts. Personality and Social Psychology Bulletin 41(7): 887–900.CrossRefGoogle Scholar
  90. 90.
    Young, L., and R. Saxe. 2009. An fMRI investigation of spontaneous mental state inference for moral judgment. Journal of Cognitive Neuroscience 21(7): 1396–1405.CrossRefGoogle Scholar
  91. 91.
    Cushman, F., L. Young, and M. Hauser. 2006. The role of conscious reasoning and intuition in moral judgment testing three principles of harm. Psychological Science 17(12): 1082–1089.CrossRefGoogle Scholar
  92. 92.
    Harenski, C.L., and S. Hamann. 2006. Neural correlates of regulating negative emotions related to moral violations. NeuroImage 30(1): 313–324.CrossRefGoogle Scholar
  93. 93.
    Hofmann, W., D.C. Wisneski, M.J. Brandt, and L.J. Skitka. 2014. Morality in everyday life. Science 345(6202): 1340–1343.CrossRefGoogle Scholar
  94. 94.
    Gray, K., and D.M. Wegner. 2009. Moral typecasting: divergent perceptions of moral agents and moral patients. Journal of Personality and Social Psychology 96(3): 505–520.Google Scholar
  95. 95.
    Cikara, M., R.A. Farnsworth, L.T. Harris, and S.T. Fiske. 2010. On the wrong side of the trolley track: neural correlates of relative social valuation. Social Cognitive and Affective Neuroscience 5(4): 404–413.CrossRefGoogle Scholar
  96. 96.
    Fiske, S.T., A.J. Cuddy, P. Glick, and J. Xu. 2002. A model of (often mixed) stereotype content: competence and warmth respectively follow from perceived status and competition. Journal of Personality and Social Psychology 82(6): 878–902.Google Scholar
  97. 97.
    Graham, J., J. Haidt, and B.A. Nosek. 2009. Liberals and conservatives rely on different sets of moral foundations. Journal of Personality and Social Psychology 96(5): 1029–1046.Google Scholar
  98. 98.
    Loewenstein, G. 2000. Emotions in economic theory and economic behavior. American Economic Review: 426–432.Google Scholar
  99. 99.
    Nordgren, L.F., J. van der Pligt, and F. van Harreveld. 2007. Evaluating Eve: visceral states influence the evaluation of impulsive behavior. Journal of Personality and Social Psychology 93(1): 75–84.Google Scholar
  100. 100.
    Eibach, R.P., L.K. Libby, and J. Ehrlinger. 2009. Priming family values: how being a parent affects moral evaluations of harmless but offensive acts. Journal of Experimental Social Psychology 45(5): 1160–1163.CrossRefGoogle Scholar
  101. 101.
    Levenson, R.W., L.L. Carstensen, W.V. Friesen, and P. Ekman. 1991. Emotion, physiology, and expression in old age. Psychology and Aging 6(1): 28–35.Google Scholar
  102. 102.
    Decety, J., K.J. Michalska, and K.D. Kinzler. 2011. The developmental neuroscience of moral sensitivity. Emotion Review 3(3): 305–307.CrossRefGoogle Scholar

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© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.Columbia UniversityNew York CityUSA

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