Testing the somatic marker hypothesis in decisions-from-experience with non-stationary outcome probabilities.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Behavioral Economics

Background:

• The Somatic Marker Hypothesis (SMH) proposes that physiological signals (somatic markers) influence experience-based decision-making by tagging options as good or bad.
• These markers are thought to aid in differentiating between advantageous and disadvantageous choices during deliberation.

Purpose of the Study:

• To investigate the role of somatic states in decision-making under conditions of uncertainty and changing probabilities.
• To test the predictive power of anticipatory and outcome-related physiological responses on choice behavior.

Main Methods:

• Two decision-from-experience tasks were conducted with 72 participants in total, involving repeated choices between two unlabeled options with varying win/loss probabilities.
• Skin conductance (SC) was measured to assess emotional intensity, with analyses focusing on pre-choice (anticipatory) and post-choice (outcome) SC.
• Participants' ability to adapt choices following unannounced shifts in optimal outcomes was assessed.

Main Results:

• Participants generally selected optimal options and adapted to payoff changes, though performance decreased after switches.
• Outcome-related skin conductance was higher for losses than wins in one study, and when forgone outcomes were positive.
• Anticipatory skin conductance did not reliably predict optimal decision-making.

Conclusions:

• The findings offer limited support for the Somatic Marker Hypothesis's proposed mechanism in this context.
• The study highlights the necessity of employing diverse methodologies, varied tasks, and large sample sizes for robustly evaluating the influence of somatic states on decision-making.