The 24 papers that form this new book are mostly consistent with IGT developmental issues over the past 20 years, such as the application of IGT in clinical scenarios, integrative investigations with combined brain imaging technology and the establishment of new models and theories. However, it is also necessary to continue global investigations and debate with regards to some existing and unresolved issues related to the IGT. For example: (1) What types of brain lesions (mental dysfunction) does the IGT truly measure? (2) Can SCRs be combined with the IGT to form a critical index of somatic markers? (3) Does the IGT measure ability for implicit or explicit learning? (4) Does EV or gain/loss frequency primarily guide decision-making behavior in the IGT? (5) Is it possible to devise a more sensitive data analysis method that can allocate more specific brain responses to the precise behaviors of IGT performance, such as the events of win, loss, and the switching of card decks? We recommend that future studies of IGT consider these questions seriously and provide in-depth investigations and discussions.