Creativity is a key aspect of human cognition, essential for solving novel problems, adapting to change, and driving progress in diverse domains, from daily life to science and the arts. Despite its fundamental role, the cognitive and neural mechanisms underlying creative thinking remain incompletely understood. This thesis aims to clarify the architecture of creative cognition and its disruption in neurodegenerative disease, by investigating the brain systems and cognitive processes that support the production of creative ideas. Based on current theories, we hypothesized that remote thinking, a key aspect of creative cognition enabling the activation of mutually distant semantic elements, relies on two complementary processes: spontaneous remote thinking, shaped by the structure of semantic memory and supposedly supported by the default-mode network (DMN), and goal-directed remote thinking, guided by top-down executive control expected to be supported by the executive control network (ECN). Additionally, we proposed that higher-order executive functions, also relying on the ECN, are required to combine multiple remote associations in coherent, meaningful ways. To explore these mechanisms, we used an interdisciplinary approach combining original cognitive tasks and multimodal brain imaging in both healthy individuals and patients with behavioural variant frontotemporal dementia (bvFTD), a neurodegenerative disease marked by atrophy in brain regions central for creative thinking. Our findings reveal four key cognitive components of remote thinking: the spontaneous activation of remote semantic associations, the Intentional Generation of Remote Semantic, Associations, Cognitive Inhibition of unoriginal ideas, and Verbal Initiation. These processes were found to be dissociable both behaviourally and neurally. Importantly, we found a critical role for the Intentional Generation of Remote Semantic Associations and for goal-directed remote thinking in general of the DMN, particularly the rostromedial prefrontal cortex (PFC), demonstrating the involvement of the DMN in goal-directed aspects of creative cognition. In contrast, spontaneous remote thinking not only involved the DMN but also primarily the ECN, highlighting the involvement of controlled processes in so-called spontaneous associative thinking. We further demonstrated that the rostrolateral PFC, within the ECN, plays a key role in combining remote ideas, thus enabling the generation of meaningful and original responses. These results point to a functional integration within the rostral PFC, which bridges generative and combinatory processes supported by the DMN and ECN, respectively. This integrative role was further supported by our finding of a mediolateral functional gradient within the rostral PFC, connecting and segregating the rostromedial and rostrolateral PFC, and thereby the DMN and ECN. This gradient was found to be essential for creative performance and was disrupted in bvFTD, mediating disease-related creativity impairments. Additionally, we showed that all assessed goal-directed processes were impaired in bvFTD, with Cognitive Inhibition deficits emerging as a primary contributor to reduced creative abilities. By combining cognitive theory, neuroimaging, and lesion data, this thesis provides a comprehensive and mechanistic account of creative cognition. It advances theoretical models and offers translational perspectives for assessing and supporting creativity in clinical populations.
Victor Altmayer (Mon,) studied this question.