Abstract
The brain can be seen as a complex adaptive system (CAS), analogous to ant colonies, economy or the internet. CAS are characterized by emergence, in which an emergent property of a CAS is one that is not a property of any component of that system. It is the very specific connections between the components of a CAS that generate emergent properties. Brain connectivity can be captured as structural connectivity, functional connectivity or effective connectivity. Neuroplasticity is the capacity of the nervous system to modify its structural and functional organization to a changing environment, thereby changing its emergent properties. As such brain disorders can be considered emergent properties of altered brain connectivity.
All neuromodulation techniques have in common that they change the functional and effective connectivity of the brain, thereby changing the emergent properties (e.g., brain disorder) of the neuromodulated networks.
The future of neuromodulation will be based on a better understanding of how these network changes can be controlled by using better neuroimaging techniques, as well as novel stimulation devices.