Table 1.

Mean number of trials ± SEM for the three measures in Experiments 1–4 under the different testing and drug conditions

	Acquisition criterion	Trials to criterion	No. of probe trials
Experiment 1
Place version
Vehicle–vehicle	57.6  ± 12.7	63.1  ± 12.9	2.0  ± 0.7
Vehicle–tetracaine	50.3  ± 6.6	55.8  ± 7.4	1.8  ± 0.5
Tetracaine–vehicle	38.7  ± 4.3	60.3  ± 7.0*	4.8  ± 1.4**
Response version
Vehicle– vehicle	64.7  ± 11.0	64.7  ± 11.0	1.0  ± 0.0
Vehicle– tetracaine	108.3  ± 6.2**	110.8  ± 5.1**	1.3  ± 0.3
Tetracaine– vehicle	68.5  ± 11.6	68.5  ± 11.6	1.0  ± 0.0
Experiment 2
Response version
Vehicle–vehicle	57.5  ± 13.6	70.3  ± 10.3	2.3  ± 0.6
Vehicle–tetracaine	68.2  ± 10.6	73.0  ± 10.6	1.8  ± 0.5
Tetracaine–vehicle	51.0  ± 14.7	51.0  ± 14.7	1.0  ± 0.0
Place version
Vehicle– vehicle	36.2  ± 4.2	37.8  ± 4.7	1.2  ± 0.2
Vehicle– tetracaine	62.7  ± 7.8**	67.3  ± 9.7**	1.8  ± 0.5
Tetracaine– vehicle	40.0  ± 5.5	44.2  ± 3.9	1.7  ± 0.3
Experiment 3
Place acquisition
Vehicle–vehicle	56.4  ± 12.8	68.0  ± 10.5	2.2  ± 0.7
Vehicle–tetracaine	61.2  ± 12.0	64.2  ± 12.4	1.6  ± 0.2
Place reversal
Vehicle– vehicle	52.6  ± 6.4	55.6  ± 5.6	1.6  ± 0.6
Vehicle– tetracaine	59.4  ± 3.8	69.8  ± 8.0	2.2  ± 0.6
Experiment 4
Response acquisition
Vehicle–vehicle	68.2  ± 13.4	72.6  ± 14.4	1.6  ± 0.2
Vehicle–tetracaine	70.0  ± 18.5	79.2  ± 17.8	1.8  ± 0.4
Response reversal
Vehicle– vehicle	71.6  ± 15.8	75.6  ± 14.9	1.4  ± 0.4
Vehicle– tetracaine	72.0  ± 15.7	73.4  ± 16.0	1.2  ± 0.3

Underlined is the treatment administered for that condition.

*p < 0.05 versus acquisition criterion.

**p < 0.05 versus vehicle-injected controls.