讲座：Prof.David Hansel，Université Paris Descartes
10
2015-06
邢大军老师课题组邀请了法国Université Paris Descartes的David Hansel教授到实验室做学术报告，欢迎感兴趣的老师和同学参加！以下为报告信息：
题目：From Physics to Function
时间：2:00PM, June 15th，2015
地点：脑成像中心308会议室（大会议室）
报告人：David Hansel
"Cerebral Dynamics, Learning and Memory" group
Center for Neurophysics, Physiology and Pathologies CNRS-UMR8119
Université Paris Descartes, 45 Rue des Saints Pères , Paris, France
报告摘要：Strong temporal irregularity and right-skewed, long-tailed distributions of firing rates are distinctive features of cortical spiking activity. Both features are quite puzzling upon consideration of the large number of synaptic inputs a cortical cell receives and the weak correlations among these inputs. A minimal theoretical framework accounting naturally for these features – the balance hypothesis – was proposed by van Vreeswijk and Sompolinsky in two seminal papers at the end of the 1990s. In fact, we showed recently that log-normal distributions of mean firing rates as reported in cortex in-vivo, emerge naturally in the balanced regime. I will summarize the physics and the general phenomenology of the balanced regime as well as their functional consequences for the selectivity of neuronal responses in primary visual cortex. I will address two limitations of the balance hypothesis in its “standard” formulation: 1) it precludes the multi-stability which has been argued to underly the persistent activity of during the retention period of delayed-response tasks 2) it does not account for temporal fluctuations observed in the neuronal activity on time scales on the order of 100 ms-1s as observed in cortex. I will briefly describe possible solutions to these limitations.
