The neuroanatomical organization of intrinsic brain activity measured by fMRI activity in the human visual cortex

The existence of intrinsic neuronal activity has been demonstrated at many scales using a variety of methodological approaches, yet its biological relevance is only beginning to be understood. One way to study intrinsic neuronal activity in humans is by using resting-state (RS) functional magnetic resonance imaging (fMRI). In my thesis, titled ”The Neuroanatomical Organization of Intrinsic Brain Activity Measured by fMRI in the Human Visual Cortex”, I describe new RS-fMRI analyses that reveal a remarkable amount of detail about the functional neuroanatomical organization of the human visual cortex. I applied these to investigate local and distributed brain dynamics within and between visual cortical regions, and show how these dynamics change under different stimulation conditions. I conclude my thesis by interpreting and discussing my findings in the light of various theoretical perspectives. I stress that – in addition to externally triggered responses – there is a constant stream of internal processes that we should take into account as well. While I have focused on the visual system, the approach I have developed can be applied to any cortical network to study brain dynamics in a variety of experimental conditions. In summary, the findings obtained with my new fMRI analyses provide evidence that intrinsic fluctuations in activity recorded by means of fMRI from early cortical visual field maps are pointers to functionally relevant processes. They support the use of RS-fMRI for characterizing cortical function and connectivity in health and disease.