Researchers challenge popular decision-making theory

Researchers in the Department of Psychology at Carnegie Mellon University have completed a study challenging a popular theory that claims bodily states can guide decision-making when conscious knowledge isn’t available. The paper, written by doctoral student Tiago V. Maia and James L. McClelland, the Walter Van Dyke Bingham Professor of Psychology and Cognitive Neuroscience, will be published online next week in the Proceedings of the National Academy of Sciences.

The study examines the somatic marker hypothesis, which states that when an individual faces a decision, each alternative elicits a bodily state – a somatic marker – that corresponds to an emotional reaction. According to the hypothesis, these markers influence decision-making and can guide the individual to make an advantageous choice even in the absence of conscious knowledge to guide the decision. The somatic marker hypothesis was proposed by neurologist Antonio Damasio in his best-selling book, “Descartes’ Error: Emotion, Reason, and the Human Brain.”

Maia and McClelland found that in testing the hypothesis using a simple card game, Damasio and his colleagues used a test of conscious knowledge that was not sensitive enough to detect everything the participants knew about the game; thus, individuals may have been guided by their knowledge, rather than their bodily states. Maia and McClelland also reviewed other evidence used to support the somatic marker hypothesis, and found that, in all cases, recent results suggest alternative interpretations for that evidence.
“It is important to note that our results and review of related work do not prove that the somatic marker hypothesis is wrong; however, they do undermine virtually all sources of support for it. If the somatic marker hypothesis is to remain viable, new evidence to support it will be required,” Maia and McClelland said.

McClelland is the co-director of the Center for the Neural Basis of Cognition, which is run jointly by Carnegie Mellon and the University of Pittsburgh. The Department of Psychology is one of eight departments in the College of Humanities and Social Sciences, the second-largest academic unit at Carnegie Mellon. The college emphasizes interdisciplinary study in a technologically rich environment, with an open and forward-thinking stance toward the arts and sciences.