Table 1.

Means, standard deviations (sd; corrected for within-participant comparisons), and interaction statistics for reaction time (RT) and sensitivity (d') measures from the three blocked conditions of Experiment Three. A significant interaction indicates that frequency sweeps (or average frequencies) guide attention to the upper and lower locations over and above any overall effects of specific sounds or probe location. (A) Potential probe locations at the top and bottom of the screen only. (B) Potential probe locations at the top left and bottom right only. (C) Potential probe locations at the top right and bottom left only.

		freq. sweeps		avg. freq.
		ascend.	descend.	higher	lower
mean RT in ms (sd)	Top	439 (15)	446 (15)	441 (17)	444 (12)
	Bottom	438 (16)	430 (16)	434 (14)	435 (14)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=7.791, p<0.009		F(1,35)=0.581, n.s.
mean d' (sd)	Top	3.0 (.6)	3.2 (.3)	3.1 (.3)	3.1 (.4)
	Bottom	3.1 (.4)	3.0 (.4)	3.1 (.3)	3.0 (.4)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=2.808, n.s.		F(1,35)=1.841, n.s.

		freq. sweeps		avg. freq.
		ascend.	descend.	higher	lower
mean RT in ms (sd)	Top Left	430 (17)	436 (13)	431 (13)	434 (15)
	Bottom Right	426 (17)	424 (11)	427 (13)	424 (13)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=1.615, n.s.		F(1,35)=2.860, n.s.
mean d' (sd)	Top Left	3.1 (.4)	3.1 (.4)	3.1 (.4)	3.2 (.4)
	Bottom Right	3.1 (.5)	3.0 (.5)	3.0 (.5)	3.1 (.4)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=0.690, n.s.		F(1,35)=0.037, n.s.

		freq. sweeps		avg. freq.
		ascend.	descend.	higher	lower
mean RT in ms (sd)	Top Right	432 (15)	429 (15)	428 (11)	433 (17)
	Bottom Left	428 (15)	426 (13)	424 (14)	430 (14)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=0.031, n.s.		F(1,35)=0.093, n.s.
mean d' (sd)	Top Right	3.2 (.4)	3.1 (.4)	3.2 (.4)	3.1 (.5)
	Bottom Left	3.1 (.4)	3.0 (.4)	3.1 (.4)	3.1 (.4)
freq. sweep (or avg. freq.) × position interaction		F(1,35)=0.037, n.s.		F(1,35)=2.466, n.s.