Table 1.

For each rat, the sequence of symmetrical (SY), necessary (N), sufficient (SU) and unsymmetrical (U) conditions, the values of the RI schedules in each condition and the number of session in each condition are shown. Also shown are the sums over the last five sessions of each condition of the left and right stay responses, the reinforcers obtained from the stay and switch schedule associated with each alternative, the time at each alternative and the changeovers from each alternative.

Condition	Sessions	RI schedule				Stay Responses
		Stay at Left	Switch from Left	Stay at Right	Switch from Right	Left (Bst1)	Right (Bst2)
Rat 758
SY	16	294	33	33	294	1410	22112
SY	19	33	294	294	33	16303	2098
N*	15	179	161	36	32	2160	14730
N	15	36	32	179	161	9164	3667
U*	26	50	10	83	417	4655	2051
SU	16	63	417	63	10	4868	5018
SU	15	63	10	50	417	4030	5905
SY	16	38	152	152	38	8850	4255
Rat 759
SY	28	294	33	33	294	598	21624
SY	16	33	294	294	33	25130	1661
N	20	179	161	36	32	1421	12504
N	16	36	32	179	161	19541	1619
SU*	15	83	8	28	500	4146	4538
U	17	28	500	83	8	11142	1916
SU	22	28	500	28	8	4017	5230
SY	17	38	152	152	38	11326	6859
Rat 760
SY	20	294	33	33	294	783	24665
SY	27	33	294	294	33	23201	2043
N	16	179	161	36	32	2664	18959
N	22	36	32	179	161	15293	3003
U*	23	63	8	29	500	4070	8351
U	16	42	500	63	8	9704	5236
SU	17	50	8	40	500	5668	6590
SU*	15	63	500	42	8	5979	7898
Rat 761
SY	16	294	33	33	294	258	17518
SY	25	33	294	294	33	19570	1648
SY	16	294	33	33	294	1707	23156
N	18	179	161	36	32	3986	16397
SU*	15	100	9	40	333	5874	6795
U	17	40	333	100	9	13013	2486
N	16	36	32	179	161	18280	2587
SU*	15	67	333	40	10	3197	5782
Rat 762
SY	42	294	33	33	294	1408	5523
SY	17	33	294	294	33	5921	1494
N	17	179	161	36	32	2010	8259
N	23	36	32	179	161	5592	2282
SU	19	83	8	40	333	2517	3009
U	15	40	333	83	8	2922	2769
SY	20	294	33	33	294	719	13064
SU	15	67	333	67	10	4220	1000
U	20	500	79	100	9	1866	4043
Rat 763
SY	27	294	33	33	294	2069	6183
SY	19	33	294	294	33	6878	2453
N	20	179	161	36	32	2119	14460
N	15	36	32	179	161	3495	9743
SU*	15	45	8	71	333	6708	3397
U	15	71	333	45	8	3970	4459
SY	18	294	33	33	294	4569	4415
U	26	25	23	250	227	2119	14460
SU	20	125	125	56	8	5316	2096

^*Several sessions that used other values of the RI schedules preceded this condition. See text for explanation.