The effect of sex and humor in the Iowa gambling task: A behavioral and electrophysiological study

Abstract

The Iowa Gambling Task (IGT) is a popular method for examining real-life decision-making. Research has shown gender related differences in performance, in that men consistently outperform women. It has been suggested that these performance differences are related to decreased emotional control in women compared to men. Given the likely role of emotion in these gender differences, in the present thesis, we examine the effect of a humor induction on IGT performance and whether the effect of humor is moderated by gender. The first study was entitled “Humor improves women´s but impairs men´s Iowa gambling task performance” it was a behavioral study. IGT performance and parameters from the Expectancy Valence Model (EVM) were measured in 68 university students (34 men; mean age 22.02, SD = 4.3 and 34 women; mean age 22.3, SD = 4.1) during a 100 trial-IGT task. Participants were exposed to a brief video before each of the IGT decisions available; one half of the samples (17 men and 17 women) was exposed to 100 humor videos, while the other half was exposed to 100 non-humor videos during the task. We observed a significant interaction between gender and humor, such that under humor, women’s performance during the last block (trials 80–100) improved (compared to women under non-humor), whereas men’s performance during the last block was worse (compared to men under non-humor). Consistent with previous work, under non-humor, men outperformed women in the last block. Lastly, our EVM results show that humor impacts the learning mechanisms of decision-making differently in men and women. Humor impaired men’s ability to acquire knowledge about the payoff structure of the decks, and as a consequence, they were stuck in suboptimal performance. On the other hand, humor facilitated women’s ability to explore and to learn from experience, improving performance. The second study was behavioral and electrophysiological (event related potentials) and was entitled “The effect of gender and humor on the neural mechanisms associated with the Iowa gambling task” the objective was to assess experimentally the effect of gender and humor on decision-making, and to explore the neural correlates underlying this effect. Method: We recorded the EEG response of 60 participants (30 men and 30 women) while conducting the Iowa Gambling Task (IGT). We randomly assigned participants to either an experimental Humor Condition (Hc) or a control non-humor condition (NHc). Results: Women in the Hc had higher performance than women in the NHc during the performance stage of the IGT. Men in the Hc had lower performance during the learning stage, and higher performance during the performance stage, than men in the NHc. Conclusion: The mechanisms underlying the effect of humor in decision making differs by gender. And finally, the third one was entitled “The effect of humor and gender on theta and beta oscillatory activity and its relationship with IGT decision-making performance”. In this study we used humor to modulate the emotional response of subjects performing the IGT. Our behavioral and oscillatory results demonstrate that participants solve better the IGT applying either less cognitive effort or less top-down control. Ultimately, the way participants control their IGT performance is modulated by gender and condition. Women apply less cognitive effort under the humor condition and men use less top-down control under the non-humor condition.