Table 4.

Boundary separation for the letter and the brightness discrimination task, averaged over participants of each group.

Groups	Boundary Separation			ANOVA				Contrast Tests
	M	SE	99% CI	Effect	F ratio	df	Partial ƞ2	GC	Test statistic
Letter Discrimination Task
College Students	0.15	0.01	[0.13,0.17]	G	53.8**	2	0.50	1	t(57.1) = −9.0**
61–74 year olds	0.23	0.01	[0.20,0.25]	T	8.762**	1	0.07	2	t(30.6) = −10.1**
75–89 year olds	0.26	0.01	[0.20,0.24]	G × T	0.35	2	0.01	3	t(49.7) = −1.5
Brightness Discrimination Task
College Students	0.14	0.01	[0.12,0.15]					1	t(63.4) = −6.6**
61–74 year olds	0.22	0.01	[0.20,0.24]					2	t(26.5) = −5.8**
75–89 year olds	0.24	0.01	[0.22,0.26]					3	t(35.5) = −1.4

Note. G = group; T = task type; CI = confidence interval; GC = group comparison (1 = college students vs. 61–74 year olds; 2 = college students vs. 75–89 year olds; 3 = 61–74 year olds vs. 75–89 year olds).

^*p < .05;

^**p < .01.