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Aim. The somatic marker hypothesis is an influential model of human decision‐making postulating that somatic feedback to the brain enhances decision‐making in ambiguous circumstances, i.e. when the probabilities of various outcomes are unknown. The somatic feedback can be measured as autonomic responses, which are regulated by the amygdala. The failure to evoke this somatic feedback, which occurs in patients with amygdala lesions, impairs decision‐making. The purpose of this study was to investigate the decision‐making behaviour of mesial temporal lobe epilepsy patients with pre‐ and post‐epilepsy surgery to ascertain whether the decision‐making abilities of groups can be explained by means of the generation of somatic feedback responses. Methods. The preoperative group comprised 32 patients with mesial temporal lobe epilepsy due to hippocampal sclerosis, while the postoperative group comprised 23 patients who had undergone anterior temporal lobectomy. The age and gender‐matched control group consisted of 30 healthy participants. Decision‐making performances were assessed and skin resistance responses were measured simultaneously. Results. The findings of this study reveal that the decision‐making performance of preoperative patients with unilateral mesial temporal lobe epilepsy was impaired under conditions of ambiguity, i.e. they did not generate somatic feedback responses before making decisions around ambiguous outcomes, and produced significantly poor scores overall based on a decision‐making task. In addition, the resection of epileptogenic limbic structures positively affected the generation of somatic feedback responses, as demonstrated by the significant difference between the magnitudes of autonomic responses of the pre‐ and post‐operative groups. Conclusions. The findings of the study validate the contribution of mesial temporal lobe structures to decision‐making behaviour, and also point to the importance of examining the connectivity patterns between the neural structures involved in the decision‐making network.

Objective: In present study, age related changes in decision-making behavior of healthy participants through the years beginning from adolescence and through later maturity as assessed by Iowa Gambling Test and performance differences between gender and age groups were examined and were compared in a cross-sectional design. Considering the confounding effects of participants' executive functions and their impulsivity levels decision-making performances, the correlations with these variables were also investigated. Method: Decision-making behavior of 157 healthy participants with age ranges 13-80 were divided into 4 groups (13-17, 18-35, 36-60, 60 and above). Executive functions were assessed by Wisconsin Card Sorting Test and impulsivity was assessed by Barratt Impulsivity Inventory. Results: Between-subjects effects revealed that both gender and age had significant effects on decision-making performance. According to paired comparisons, 18-35 age group had significantly higher total net scores than the 13-17 age group. Male participants had significantly higher total net scores than the female participants. Despite each group increased their IGT scores within themselves throughout the test, 13-17 and 60 above groups did not achieve the levels of other groups' scores. No significant correlations were found between impulsivity and decision-making performance, a weak significant correlation was found between perseverative errors and total net scores of decision-making test. Discussion:As expected, an inverted U-shaped developmental pattern of decision-making behavior, which was characterized by an increase in performance that became evident in adolescence and proceeds through early adulthood and which was subsequently followed by a decrease in performance through late maturity was determined in this study.

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