Fig. 2: Emergence of two subpopulations of excitatory neurons in the PFC module after training.
From: Flexible gating between subspaces in a neural network model of internally guided task switching
a Two example rule neurons (top) and conjunctive error x rule neurons (bottom). The solid traces represent the mean activity across trials that follow a correct trial, when those trials belong to color rule (blue) or shape rule (green) blocks. The dashed traces represent the mean activity after error trials, when those trials belong to color rule (blue) or shape rule (green) blocks. We use rule 1 and color rule, as well as rule 2 and shape rule interchangeably hereafter. b Rule neurons and conjunctive neurons are separable. The x axis represents the input weight for negative feedback, and the y axis is the difference between the mean activity over color rule trials and shape rule trials (for trials following a correct trial). As shown, the rule neurons (blue points) receive little input about negative feedback, but their activity is modulated by rule; The conjunctive error x rule neurons (red points) receive substantial input about negative feedback, but their activity is not modulated by rule (during trials following a correct trial). c The trend in b is preserved across a collection of trained networks. Here the result is shown for networks with subtractive dendritic nonlinearity. Networks with divisive dendritic nonlinearity show a similar pattern (Supplementary Fig. 3).
