Figure 6. Sampling and tracking errors.

Synaptic drive was trained to learn 1 s long trajectories generated from OU noise with decay time ${\tau }_c$. (a) Performance of networks of size $N=500$ as a function of synaptic decay time ${\tau }_s$ and target decay time ${\tau }_c$. (b) Examples of trained networks whose responses show sampling error, tracking error, and successful learning. The target trajectories are identical and ${\tau }_c=100$ ms. (c) Inverted ‘U’-shaped curve as a function of synaptic decay time. Error bars show the s.d. of five trained networks of size $N=500$. (d) Inverted ‘U’-shaped curve for networks of sizes $N=500$ and $1000$ for ${\tau }_c=100$ ms. (e) Network performance shown as a function of ${\tau }_s/{\tau }_c$ where the range of ${\tau }_s$ is from 30 ms to 500 ms and the range of ${\tau }_c$ is from 1ms to 500ms and $N=1000$. (f) Network performance shown as a function of $1/\sqrt{N{\tau }_s}$ where the range of ${\tau }_s$ is from 1 ms to 30 ms, the range of $N$ is from 500 to 1000 and ${\tau }_c=100$ ms.