应物理学院俞连春副教授邀请，悉尼大学杨冬平博士近日将到访我院，并做学术报告。欢迎广大师生届时参加！

题目： Large-scale Brain Dynamical Mechanisms for Absence Seizures

时间：2019年4月19日（星期五）上午10：00

地点：格致楼4022

摘要：

Absence epilepsy is characterized by a sudden paroxysmal loss of consciousness accompanied by oscillatory activity propagating over many brain areas. A physiologically based corticothalamic model of large-scale brain activity is used to analyze critical dynamics of transitions from normal arousal states to epileptic seizures, which correspond to Hopf bifurcations. This relates an abstract normal form quantitatively to the main underlying physiologies that includes neural dynamics, axonal propagation, and time delays. Thus, a bridge is constructed that enables normal forms to be used to interpret quantitative data. This model is further investigated with focal spatial heterogeneity, numerically and analytically. An emergent spatiotemporal dynamic is found for seizure localization, whose spatiotemporal properties are comparable with experimental observations, providing a new biophysical explanation of the temporally higher frequency, but spatially more localized cortical waves observed in genetic rodents that display characteristics of human absence epilepsy, from the perspective of large-scale brain dynamics. Predictions are also presented for further experimental test. Thus, we propose a dynamical mechanism to unify the global and focal aspects of absence epilepsy with focal absence seizures associated with localized seizures, and the global ones associated with generalized seizures. More details of cellular nonlinear dynamics or heterogeneous connectivity can be further introduced into the large-scale Physical brain system for future studies.

报告人简介：

杨冬平博士目前在悉尼大学物理系复杂系统研究组做博士后。2011年毕业于厦门大学，获得生物物理博士学位。博士期间致力于复杂网络和博弈共演化动力学以及细胞内钙离子通道的生物建模。之后前往香港浸会大学周昌松组里做博士后，开始转向研究计算神经科学，理论研究发现脑皮层的多尺度活动性质刚好符合信息容量的成本－效益原理框架。目前利用非线性动力学理论理解大尺度大脑系统中的时空动力学以及探寻潜在的预警信号， 例如大脑清醒到睡眠的转变过程，正常状态到癫痫状态的不同转变类型，以及癫痫的泛化过程。