Physiological Manifestations in Strategic Decision-Making under Conditions of Uncertainty: Insights from the Iowa Gambling Task

Decision-making is a key topic in cognitive sciences and neuroeconomics. While many studies have analyzed individual performance under conditions of uncertainty within the framework of the Iowa Gambling Task (IGT), few have examined the physiological manifestations during the task and their alignment with participants’ strategies, particularly in the context of healthy dynamics, free from limitations. This study aimed to investigate decision-making under uncertainty in a stress-free environment (free from time constraints or emotional interventions) using a modified IGT. Twenty-eight participants (12 men, 16 women; 21.96 ± 3.82 years) completed the task in five stages, with 50 trials in each stage. Four physiological signals were recorded: Blood Volume Pulse (BVP), temperature, respiration rate, and Skin Conductance Response (SCR). At first, participants preferred disadvantageous cards (A and B) but gradually shifted to advantageous cards (C and D). Initial stages showed a slight increase in body temperature and an LF/HF ratio above one, indicating increased sympathetic activity and physiological stress. As the task progressed, individuals adapted to the rules and adopted more optimal strategies. Stage 4 marked a turning point with significant decreases in SCR and an LF/HF ratio below one, reflecting reduced stress. In the final stage, decreased BVP and an LF/HF ratio of one indicated a balance between the sympathetic and parasympathetic systems. Finally, it can be acknowledged that the task structure was useful in identifying the roles of the cards. Additionally, advancing in conditions of uncertainty through decision-making reflects a dynamic balance between neural systems related to reward and stress.