Figure 1

In the first 150 trials, the value of seeking natural rewards at all levels converge to r=10 (a). For the case of drug, however, the direct pharmacological effect of drug (D=2) results in the value of drug seeking to become much higher than at the detailed levels, than at the abstract levels (b). If both of these actions be followed by punishment of magnitude -16 (the last 150 trials), then whereas cognitive loops assign a negative value to drug-seeking choice, motor-level loops find drug-seeking desirable (assign a positive value to it).