. Author manuscript; available in PMC: 2023 Jul 10.

Published in final edited form as: Psychopharmacology (Berl). 2021 Apr 24;238(8):2261–2273. doi: 10.1007/s00213-021-05850-7

Table 2.

Preferred model results for acquisition, escalation, and extinction in Experiment 2.

	Model
Fixed Effects	Acquisition	Escalation	1^st h Escalation	Extinction
Initial Status
Intercept	3.66^****	3.54	11.29^****	1.82^****
LgA		37.23^****	−2.17	−0.21^**
Female	0.96	17.30^**	2.54^*	−0.077
Session
Intercept	−0.50^**	0.06	0.22
LgA		6.08^**	0.79^*
Female	−0.16	0.78	0.49
Session × Session
Intercept		0.002	−0.004
LgA		−0.13	−0.01
Female		−0.03	−0.02
Log(session)
Intercept				−0.68^****
LgA				0.29^****
Female				−0.04
Active
Intercept	−0.004
Female	0.39
Active × Session
Intercept	1.37^****
Female	0.72^*
Random Effects
L1 Residual	11.08^****	174.43^****	12.44^****	0.025^****
Cov (I,S)	−0.39	6.14	−0.7	−0.02^*
Var (I)	3.34^**	230.20^***	9.49^**	0.026^**
Var (S)	0.08	28.65^***	0.71^**	0.025^**
Cov (I, Q)		−0.57	0.01
Cov (S, Q)		−1.14^***	−0.02^*
Var (Q)		0.05^***	0.001^**
−2 LL	2663.2	5638.0	3804.8	−295.8

The coefficients for the final preferred models for Experiment 2 acquisition, escalation, 1^st h escalation, and extinction are shown above. Cov = covariance, Var = variance, −2 LL = −2 Log Likelihood, I = intercept, S = slope, Q = quadratic.

(p < .05),

^**

(p < .01),

^***

(p < .001), and

^****

(p < .0001).