Table 2.

Group Differences in RT under Increasing Uncertainty Load.

	Block 1 (Practice)			Block 2 (Test)
	CN	AD	t	CN	AD	t
Externally Cued Task
1.00 bits	38.9 (6.2)	57.1 (29.6)	2.09	44.3 (5.8)	73.8 (36.0)	3.03**
1.59 bits	41.1 (8.5)	70.2 (36.4)	2.70*	49.9 (6.9)	95.4 (53.8)	2.92*
2.00 bits	39.7 (8.5)	71.0 (36.4)	2.81*	53.8 (5.5)	102.9 (50.8)	3.33**
2.32 bits	39.7 (8.7)	67.8 (26.6)	3.49**	68.2 (17.7)	122.3 (65.3)	2.79*
Internally Cued Task
0.49 bits	47.2 (7.4)	62.0 (26.8)	1.91	44.6 (7.3)	57.6 (21.3)	2.07
1.37 bits	53.3 (12.2)	53.5 (17.4)	1.88	50.3 (9.7)	61.6 (15.8)	2.15*
2.06 bits	57.8 (7.6)	76.4 (14.7)	4.02***	54.3 (6.1)	72.7 (13.9)	4.34***
2.32 bits	59.0 (7.7)	79.2 (26.6)	2.62*	56.8 (6.1)	77.7 (24.3)	3.00**

Note. Values represent M(SD). In the externally cued task condition, Block 1 consisted of a blank deck of cards sorted into the specified number of piles; this served as a control for psychomotor speed. CN = cognitively normal; AD = Alzheimer’s Disease.

^*p < .05,

^**p < .01,

^***p < .001