Table 5.

Means and standard deviations (in parentheses) of group mean parameters with the PVL-DecayRI model.

PVL DecayRI parameters	HC	A	H
Decay rate (A)	0.736 (0.068)	0.809 (0.072)	0.730 (0.087)
Reward sensitivity (α)a	0.053 (0.043)	0.310 (0.129)	0.122 (0.074)
Response sensitivity (c)	0.216 (0.038)	0.186 (0.040)	0.210 (0.050)
Loss aversion (λ)b	1.262 (0.543)	0.910 (0.494)	0.110 (0.108)

HC, healthy controls; A, amphetamine; H, heroin.

^aHC < A.

^bHC > H.