Structure funcitional effectness connectivity

Many measures of connectivity exist, and they can be broadly divided into measures of functional connectivity (denoting statistical dependencies between measured signals, without information about causality/directionality), 功能连接 统计相关但是没有因果或者走向 and measures of effective connectivity, which describe directional interactions.   有方向的图论表示


EEG采集的信号是原始信号的多个叠加的结果,因此在计算conectivity的时候 要非常的小心 with  caution! 下面 这列子描画出相关的影响 Simulated data with common pick-up and different noise levels when working withe EEG singal that are picked up by the individual channels invariablely consisit of instant mixtures of the underlying source singals. This mixing

Brain connectivity的含义

经过这一年 做事要循环渐进  不能一步吃个胖子 connectivity 搞了两周  从图论到各种 今天用个列子也理解下 connectivity到底什么玩意 这里面用到一个  multivariate autoregress mode  多参数自回归模型 就是 有多个变量的多个函数   这个模型试图找出这些函数之间的组合关系 (相关性,相关性就是connectivity的基础) 如 x(t) = 0.8*x(t-1) – 0.5*x(t-2) y(t) = 0.9*y(t-1) + 0.5*z(t-1) – 0.8*y(t-2) z(t) = 0.5*z(t-1) + 0.4*x(t-1) – 0.2*z(t-2)   t-1