Learning the payoffs and costs of actions
Fig 6
Effects of D2 blocking on the willingness to exert effort.
(a) Schematic illustration of the experimental setup. (b) Action selection in control state. Green and red circles on the left denote striatal Go and No-Go neurons associated with pressing the lever, while the green and red circles on the right denote the neurons associated with approaching the free food. The strengths of the synaptic connections, which result from simulated learning, are indicated by the thickness of the arrows, and the labels. The parameters used for the simulations were obtained through a fit of the model to the experimental data. The blue circle represents a population of dopaminergic neurons, and its shading indicates the level of activity. (c) Action selection in the dopamine-depleted state. The notation is the same as in panel (b), with the thick red circles indicating enhanced activity in the No-Go population, which results from blocked dopaminergic inhibition (symbolised by the smaller inhibitory projections of the dopamine neurons).