Phase Synchronization in Brain Collective Dynamics

Neuronal synchronization plays an important role in brain function. It has been shown to be necessary for memory consolidation as well in locomotion, for example. However, abnormal synchronous neuronal activity can be damaging as in Parkinson's disease and epilepsy. Epileptic seizures are characterized by an hyper-synchronization of brain electrical signals, and developing approaches for both detection and prevention of seizures has proven to be rather difficult. In this work we combine EEG recordings of brain electrical activity, along with a phase detection method, to characterize abnormal neuronal synchronization during seizures. The phase locking value index is used to quantify synchronization among distinct brain areas during the typical pre-ictal, ictal and post-ictal stages of seizures. We find that during the ictal stage, synchronization is highly more prevalent, and implement classifier methods to quantify synchronous regimes. Our results further indicate that multiple performance indicators are needed to maximize the chances of selecting the most reliable classifier. The outcomes of this work point to potential implementation of technologies capable of detecting seizures early enough for the introduction of preventive measures.