Figure 5.
The responses of the reduced network model to a weakly and transiently selective external input in the various regimens of the phase diagram. Network parameters are given in Table 1. Activities in and inputs to circuit 1 (resp. circuit 2) are plotted with solid lines (resp. dashed lines). A, The external input. Top, The input to the cortical populations in the two circuits. Bottom, The input to the striatum. The responses of the cortex (red), the thalamus (black), and the GPi (blue) are plotted in B, the symmetry-breaking regimen (GStrCtx = 0.7); C, the linear regimen (GStrCtx = 0.4); and D, the oscillatory regimen (GStrCtx = 0.05). Note that only one cortical population is activated in the symmetry-breaking regimen (B), whereas both populations are activated in the other regimens. E, The response of the network to a strong cortical input in the oscillatory regimen (GStrCtx = 0.05). The striatal input and the profile of the cortical input are as in A. The amplitude of the latter has been increased by a factor of 3. The oscillation is suppressed because the thalamus is silent, and subsequently the feedback loops are open. F, The response of the network to the input displayed in A in the multistability regimen (GStrCtx = 0.9). As in the symmetry-breaking regimen, one cortical population is activated, whereas the other is silent.