Understanding the effective dynamics of the human brain.

Abstract

While the cellular structure and behaviour of single neurons is well understood, how groups

of neurons work together to perform a certain brain function is not. With its sensitivity to

external stimuli and dense interconnectedness, the mapping of these functional groups of neurons

within the human brain represents a signi cant research challenge. Thet invasive nature of

direct neuronal observation presents an ethical barrier to research. Even with technological

advancements in brain imaging, data is inherently noisy and subject to numerous statistical

procedures before meaningful inferences can be made. In this study, we utilise the complete-link

algorithm of hierarchical clustering which is a mathematical method designed to nd similar

groups of data. The algorithm will be used to nd clusters of neurons which may be seen as

the functional areas of the brain. Following clustering, the dynamics of these functional areas

will be studied by adopting a cluster synchronisation based approach to provide insight into

the workings of the brain. Two sets of data will be analysed. The rst will be the simulated

neuronal activity of a semantic dyslexic to test the feasibility of the approach. The second will

be a time series of fMRI scans of a single subject performing a visual task under conditions of

attention or no attention.