Figure 2

Final states of a single unit show history dependence for certain durations \(\tau _{\text{dur}}\) and amplitudes \(I_{\text{app}}\) of an applied stimulus. Rows compare the effects with (row a) and without (row b) short-term synaptic depression. Columns differ by whether the initial state of the system is the ON state (columns 1 and 3) or the OFF state (columns 2 and 4). Columns 1 and 2 depict the results of a single stimulus presentation, while columns 3 and 4 depict the results of a sequence of two stimulus presentations. In columns 1 and 2, the final state is color-coded as red=ON and blue=OFF. In columns 3 and 4 the red region and blue region indicate the final state is ON (red) or OFF (blue) while the yellow regions marked by a white star show maximal history dependence where the input repeatedly switches the state back and forth. Markers correspond to simulations in Fig. 1. No such repeated switching is observed without synaptic depression in panels (b3) and (b4)