Table 1.

Slopes at threshold of the estimated psychometric functions for individual participants. The slopes with the precursor were derived from the condition with the 1000-ms precursor and 10-ms gap.

Subject Number	Present/Absent		Up/Down
	No precursor	With precursor	No precursor	With precursor
1	2.24	1.03	.21	1.20
2	.99	1.50	2.86	1.02
3	.75	2.08	1.25	2.00
4	1.54	1.60	2.30	2.88
5	1.14	1.42	1.10	1.70
6	1.20	1.57	.57	1.45
7	3.40	.75	.91	1.15
8	1.62	1.12	4.54	1.76
9	1.50	.57	.22	1.18
10	1.24	.74	2.08	.42
11	1.34	2.20	.44	1.97
12	.44	1.14	1.26	1.76
13	1.48	1.61	2.53	1.67
14	.79	.73	1.57	1.07
Mean (SD)	1.41 (0.72)	1.29 (0.51)	1.56 (1.21)	1.52 (0.59)