Radwa KHALIL

• Models of cognition-based brain networks and functions are enormous in number and intricate in function. However, it is possible to compare modules of hierarchically segregated models against one another and model them based on a range of empirical data. It is essential to elucidate the neurobiological contribution of executive functions (EFs) to cognitive functions such as decision making (DM) and creative thinking. The prefrontal cortex (PFC) is associated with several EFs. The PFC is part of a deliberate inhibitory control (IC) network; it is also a central node for problem-solving and the creative ideation process. Nevertheless, several cognitive domains for inhibition and flexibility correspond to distinct cortico-frontal networks. An integrated computational–experimental framework could provide insight into the root of EFs. This PhD thesis aims to explore the role of models of cognition-related brain networks and functions. The thesis addresses 1) the computational perspective on decision-making and creative thinking and 2) the experimental perspective on creative thinking, supported by relevant peer-reviewed publications. The computational perspective on DM and creative thinking is concerned with validating computational modeling through spiking neural network (SNN) and connectionist models. The experimental perspective on creative thinking is concerned with the relationships among creative cognition, creative drive, and their associated neuromodulator systems––a subject on which information has, until now, remained scattered and elusive. The experimental study used a non-invasive brain stimulation method (transcranial direct current stimulation [tDCS]) to examine the role of the inferior frontal gyrus (IFG) in divergent thinking (DT) and whether changes in the activity of the IFGs and IC would mediate variations in DT.