Table 1.

Average parameters and results in the four series of experiments

Series	1 (n = 20)	2 (n = 14)	3 (n = 16)	4 (n = 19)	Total (n = 69)	Exp versus Con Wilcoxon T	Series K–W H
Shock (mA)
Exp	5.5	6.2	4.8	5.5	5.5	723.0NS	1.69NS
Con	5.5	5.0	5.0	5.2	5.0
Criterion (mm)
Exp	0.62	0.62	0.62	0.62	0.62	2.0NS	1.29NS
Con	0.62	0.62	0.62	0.62	0.62
First response (s)
Exp	28	28	40	41	33		10.61*
Time above criterion (%)
Pre
Exp	1	5	4	2	3	1145.5NS	2.56NS
Con	2	5	3	2	2
Phase I training
Exp	92	92	95	94	94	276.5**	2.38NS
Con	66	70	80	69	70
Phase I extinction
Exp	31	29	25	23	29	847.5*	3.47NS
Con	17	22	26	14	18
Phase II training
Exp	92	94	94	96	94	795.5*	3.02NS
Con	75	84	94	95	88
Phase II extinction
Exp	22	19	14	31	19	692.0**	1.65NS
Con	11	12	13	13	12
Spontaneous contractions (s)
Pre
Exp	34	108	101	29	65	1081.5NS	6.53NS
Con	60	99	78	39	63
First extinction
Exp	127	168	106	77	106	875.0*	7.69NS
Con	84	78	107	69	79
Last extinction
Exp	65	104	60	70	69	1015.5NS	4.99NS
Con	62	82	57	72	71
Baseline shift (mm)
Pre
Exp	0	0	0	0	0	812.0NS	4.07NS
Con	0	0	0	0	0
First extinction
Exp	1.41	0.78	0.78	0.94	0.62	842.5NS	1.96NS
Con	0.94	0.31	1.09	0.62	0.62
Last extinction
Exp	1.72	0.31	0.62	1.56	0.94	604.5*	1.06NS
Con	0.47	−0.16	0.16	0.62	0.31

Median values of the parameters and results in the four series of experiments (see Materials and Methods) and overall are shown. The experimental and control animals were compared by Wilcoxon’s signed-ranks tests (T), and the four series of experiments were compared by Kruskal–Wallis ANOVAs (K–W H). Exp, Experimental; Con, control; Pre, pretest period.

*p < 0.05;

**p < 0.01;

NS, not significant.