Table 1. Parameters Used to Simulate Data from Drift-Diffusion Model, Derived from Ratcliff, Thapar, et al. (2004).

Scenario	Drift rate easy (v1)	Drift rate hard (v2)	Boundary separation (a)	Nondecision time (Ter)
Note. Individual parameter values in each scenario were generated from a normal distribution with means given in the first four rows and the SDs shown in the bottom row. Mean parameters that were varied between groups in each scenario are highlighted in bold, with the range shown for older adults. In Scenarios B, C, and D, the effect between groups in each scenario can be calculated by multiplying the Cohen’s d value by the SD (e.g., .2 × 50 ms for the smallest effect in nondecision time in Scenario D). For Scenario A, the difference of interest is the group difference in the difference between easy and hard drift rates. The SD of the difference (easy–hard drift rates) was .044.
Domain-specific deficit (A)	.480	Young: .310	.155	490
		Old: .301–.248
General slowing (B)	Young: .480	Young: .310	.155	490
	Old: .466–.382	Old: .296–.212
Strategic slowing (C)	.480	.310	Young: .127	490
			Old: .134–.179
Nondecision time (D)	.480	.310	.155	Young: 440
				Old: 450–510
SDs (all scenarios)	.07	.07	.037	50