最近的研究已使用傳遞熵來測量大量神經元之間的有效連結。對這些網絡的 分析為神經網絡中的信息傳遞提供了新穎的見解。信息傳遞是通過傳遞熵的 估計來量化的，傳遞熵是作為無模型方法測量神經元之間有向線性和非線性 相互作用的方法。兩個序列之間的高信息傳遞是神經元之間興奮性突觸的證 據。但是抑制性突觸也顯示出重要的信息傳遞。我們通過揭示信息傳遞是來 自興奮性突觸還是抑制性突觸來擴展有效連結的分析。為了區分這些類型的 相互作用，我們分析了每種傳遞類型的符號相反的局部傳遞熵，從而使我們 能夠區分分類後的局部傳遞熵。我們進一步探索動態狀態條件以估計傳遞熵， 以消除神經群體中高度同步的驟放事件期間的網絡效應。像以前的研究一樣， 我們將這些方法應用於具有隨機突觸延遲和可塑性的 Izhikevich 神經元網絡 進行神經元發火序列的模擬，我們證明了可以推斷出抑制性和興奮性突觸， 並改善了網絡重構。此外，我們證明分類局部傳遞熵對於解決伊辛逆問題也 很有用。我們的模擬中表明，對於一個隨機連接的 Ising 網絡系統，我們可以 通過估計成對分類局部傳遞熵來推斷正和負相互作用的強度。;Recent studies have used transfer entropy to measure the effective connectivity among large populations of neurons. Analyzing these networks gave novel insight on the information transfer in neural networks [1]. Transfer of information as quantified by the estimation of transfer entropy [2] which measures the directed linear and non-linear interactions between neurons as a model-free method. High information transfer between two spike trains is evidential for an underlying excitatory synapse between the neurons. However, also inhibitory synapses show significant information transfer. We extend the effective connectivity analysis by revealing whether the information transfer is coming from an excitatory or an inhibitory synapse. To distinguish these types of interactions we analyze the local transfer entropies [3] which are opposite signed for each interaction type, allowing us to define the sorted local transfer entropy as the discriminating quantity. We further explore dynamic state conditioning for estimating transfer entropy [4] in order to remove the network effects during highly synchronized bursting events in the neural population which are not indicative of a direct synaptic interaction. Applying these techniques to the spike trains of simulated networks of Izhikevich neurons with random synaptic delays and spike-timing-dependent plasticity evolved connection weights like in a previous study [5], we show that inhibitory and excitatory synapses can be inferred and the network reconstruction improved. Furthermore we show that sorted local transfer entropy is also useful to solve the inverse Ising problem [6]. In our simulations we show that for a system of randomly connected Ising nodes we can infer the interaction strength for both positive and negative interactions by estimating the pairwise sorted local transfer entropies.
