Table A1.

Correlations Between Processing Speed Tasks and Executive Control Composite Scores in Experiment 1

	Working Memory^	Inhibition	Task Switching
ORT	−.053	.546**	.233
SRT	−.073	.066	.246
BC	.049	.193	.217
HM	−.019	.183	.194
DC	−.114	.204	.385**
CN	−.151	.468**	.367**
CRT1	−.470**	.314*	.441**
CRT2	−.374**	.378**	.320*
CRT3	−.341**	.362**	.215
AS	−.343**	.237	.313*

Note—More complex processing speed measures (perceptual speed; CN through AS) were often correlated with executive control in young adults (12 out of 15 correlations between processing speed task and executive function construct reached p < .05), but simpler speed measures (psychomotor speed; PL through DC) were rarely correlated with any of the executive control composites (2 out of 15 correlations reached p < .05). n = 58;

^*p < .05;

^**p < .01;

^{^}negative because larger is better for working memory tasks. Dashed line separates psychomotor and perceptual speed tasks. Processing Speed Measures (from low to high in executive control contributions): ORT = offset RT; SRT = simple RT; BC = box completion; HM = horizontal line marking; DC = digit copying; CN = color naming; CRT1 = choice RT, color task; CRT2 = choice RT, color and shape tasks; CRT3 = choice RT, quantity and identity tasks; AS = addition and subtraction tasks. Task Switching composite = average of global switch cost, color and shape switching task, global switch cost, quantity and identity switching task, and switch cost, addition and subtraction switching task z scores; Inhibition composite = average of stop signal reaction time, stop signal task, color minus non-color word completion time, Stroop task, and antisaccade percent errors, antisaccade task z scores; Working Memory composite = average of digit span backward, spatial span backward, reading span total items correct, counting span total item correct, and operation span total items correct z scores.