Cognitive effects of glucose consumption

The role of glucose in enhancing cognitive performance has been a subject of interest, with conflicting findings across various studies. Understanding the circumstances under which glucose administration yields benefits, harms or remains inconsequential for subsequent performance is of paramount importance, given its prominence as the dominant form of carbohydrate in our physiological energy supply. Even the neural processing of each and every word of this thesis will likely be powered by glucose, just as the thoughts that brought such words together. As the role of glucose in our physiology is of fundamental significance for both our body and mind, it also raises critical questions regarding the management of individuals with impaired glucose regulation, such as those with diabetes, spanning from infancy to old age. This doctoral thesis delves into the investigation of the cognitive effects resulting from glucose intake. Study A, B, and C represent the foundation of the overarching research project and are forming the basis of this thesis. Each of these contributions to the underlying body of research serves an empirical and a methodological purpose. Empirically, Study A investigated factors that influence interindividual differences in the magnitude of cognitive effects elicited by glucose administration, termed cognitive glucose sensitivity (CGS). Study B examined possible underlying physiological mechanisms of these cognitive effects. Study C explored CGS in a clinical context. Methodologically, the same studies represent the development of behavioral (Study A), physiological (Study B), and introspective (Study C) approaches to the study of glucose-related effects on cognition. This duality serves the purpose of answering key questions about the cognitive effects of glucose consumption, while at the same time overcoming the methodological limitations of our curiosity and encouraging the emergence of novel questions in the long term.