Table 1.

Experimental Parameters and Accuracy Data for Experiments 1–10

	Experimental parameters			Accuracy (%)
Experiment	Time limit	Prevalence high:low	Trial type counts	Low single	Low dual	Low-single vs. Low-dual	SOS effect: SOS?
1	15 s	1:1	High: 50	60.40 (12.57)	63.09 (10.72)	t(9) = 1.28	✘
			Low: 50			p = .23
			High-Low: 50			d = −0.23
			None: 100
2	15 s	2:1	High: 100	66.00 (16.22)	59.72 (16.62)	t(9) = 3.18	✔
			Low: 50			p = .01
			High-Low: 50			d = 0.38
			None: 50
3	15 s	3:1	High: 120	72.50 (12.42)	60.76 (12.23)	t(9) = 3.56	✔
			Low: 40			p < .01
			High-Low: 40			d = 0.95
			None: 50
4	30 s	2:1	High: 100	60.60 (17.26)	58.50 (19.59)	t(9) = 1.07	✘
			Low: 50			p = .31
			High-Low: 50			d = 0.11
			None: 50
5	30 s	3:1	High: 120	60.50 (13.83)	55.64 (16.67)	t(9) = 2.08	~✔
			Low: 40			p = .07
			High-Low: 40			d = 0.32
			None: 50
6	30 s	6:1	High: 150	68.00 (12.51)	57.90 (15.98)	t(9) = 2.11	~✔
			Low: 25			p = .06
			High-Low: 25			d = 0.70
			None: 50
7	Luggage line (variable rate)	3:1	High: 96	74.07 (15.11)	73.08 (11.84)	t(9) = 0.93	✘
			Low: 32			p = .38
			High-Low: 32			d = 0.07
			None: 40
8	Luggage line (constant rate)	3:1	High: 96	71.89 (12.77)	63.92 (15.11)	t(9) = 3.21	✔
			Low: 32			p =. 01
			High-Low: 32			d = 0.57
			None: 40
9	30 s	1:1 Low-single:dual	Low: 100	78.17 (7.80)	76.75 (13.22)	t(9) = 1.12	✘
			Low-Low: 100			p = .29
			None: 50			d = 0.13
10	30 s	4:1 Low-single:dual	Low: 160	74.91 (8.70)	71.63 (5.43)	t(9) = 3.10	✔
			Low-Low: 40			p = .01
			None: 50			d = 0.45

Note. Accuracy reflects mean detection rates with standard deviations in parentheses; p-values represent 1-tailed t-tests of low-salience target accuracy in single vs. dual target trials.