The Well-tempered Mind: How Brain Connectivity is Linked to Cognition

Talk given for the Royal Society of Biology on 17 September 2020. Networks in biological systems are visible at different scales: from metabolic or protein-interaction networks within cells, over networks between neurons in the brain, to social interactions between humans. Over the last 30 years, as more and more information about biological networks became available, we discovered a similar organisation across species and scales. For the set of connections in the brain, the connectome, I will discuss common principles of brain network organisation. These principles are found across systems ranging from the network between neurons in the roundworm Caenorhabditis elegans to the network between regions of the human brain. The small-world, modular, and hub architecture of brain networks allows for efficient processing of information in neural networks. Moreover, changes in this architecture are linked to brain network disorders such as dementia, schizophrenia, and epilepsy. I will outline the principles of how neural networks grow and how deficits during brain maturation can lead to cognitive deficits as observed for brain disorders [1]. Finally, computational approaches based on information about brain connectivity can be used for diagnosis and intervention. I will conclude with some examples concerning the use of brain surgery in epilepsy, early diagnosis of dementia, and use of brain stimulation in order to change connectomes towards a healthier organisation and behaviour [2]. [1] Kaiser. Trends in Cognitive Sciences, 2017. [2] Kaiser. Changing Connectomes: Evolution, Development, and Dynamics in Network Neuroscience. MIT Press, 2020. https://mitpress.mit.edu/9780262044615/