Dopamine, Affordance and Active Inference
Figure 10
This figure represents behavioral results in terms of reaction times for depleting dopamine in three regions: the superior colliculus encoding sensory salience (as in previous figure), the motor cortex encoding proprioception (middle column) and the premotor cortex encoding affordance (right column).
These results are shown using the same format as in previous figure and illustrate the qualitatively different effects of dopamine depletion in different parts of the brain (or model). The lower panels indicate the implicit projections, from the substantia nigra or ventral tegmental area, have been selectively depleted (where a red cross highlights the forward prediction errors affected). The key thing to take from these simulations is that reducing the precision of prediction errors on sensory salience induces bradykinesia and perseveration; whereas the equivalent reduction in proprioceptive affordance causes bradykinesia without perseveration. Finally, compromising the precision of changes in affordance increases perseveration and decreases bradykinesia.