Table 1.

Estimates of bias for individual pigeons.

Pigeon	Control	Saline	0.3 mg/kg	1.0 mg/kg	1.7 mg/kg	3.0 mg/kg
105	0.27	0.13	0.37	0.23	0.27	−0.28
106	−0.10	0.03	−0.13	−0.43	−0.14	—
107	0.16	0.28	0.14	0.17	−0.05	—
108	0.19	0.16	0.18	0.09	0.13	0.06
225	0.01	−0.12	0.09	−0.003	−0.25	−0.38
226	−0.14	−0.11	−0.14	0.35	0.05	0.16
227	0.09	0.15	0.30	0.02	−0.17	−0.63
228	0.06	−0.10	−0.57	0.29	0.37	—

Note. Positive values indicate a bias for the standard alternative. Dashes indicate instances in which bias could not be estimated (either because responding was completely suppressed or because the particular dose was not given at least once under each delay condition).