Welcome to a lecture by Dr. Diego Vidaurre, Oxford Center for Human Brain Activity, Oxford University, UK.
The brain needs to activate multiple networks in a temporally coordinated manner in order to perform cognitive tasks, and it needs to do so at different temporal scales, from the slowest cyrcadian cycles to fast subsecond rhythms.
I propose a novel probabilistic framework to investigate brain functional reorganisation, capable to reliably access the dynamics contained in the signal even at the fastest time scales. Using this approach we investigate several aspects of the intrinsic dynamics of the human brain.
First, we found that the brain spontaneously transitions between different networks in a predictable manner and follows a hierarchical organization that is remarkably simple, is heritable and significantly relates to behaviour.
Second, we investigate the spectral properties of the default mode network using MEG, which is revealed to be composed of two components, anterior and posterior, with very distinct spatial, temporal and spectral properties - both having a strong implication of the posterior cingulate cortex, yet in very different frequency regimes.
Finally, I show an extension of this model for task data where we incorporate the stimulus information into the model, in such a way that we can reliably find between-trial temporal differences in stimulus processing - which we argue are crucially related to learning and plasticity, and can avoid the interpretation caveats of traditional decoding techniques.
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