A. Miyake et al., The unity and diversity of executive functions and their contributions to complex "frontal lobe" tasks: A latent variable analysis, COG PSYCHOL, 41(1), 2000, pp. 49-100
This individual differences study examined the separability of three often
postulated executive functions-mental set shifting ("Shifting"), informatio
n updating and monitoring ("Updating"), and inhibition of prepotent respons
es ("Inhibition")-and their roles in complex "frontal lobe" or "executive"
tasks. One hundred thirty-seven college students performed a set of relativ
ely simple experimental tasks that an considered to predominantly tap each
target executive function as well as a set of frequently used executive tas
ks: the Wisconsin Card Sorting Test (WCST), Tower of Hanoi (TOH), random nu
mber generation (RNG), operation span, and dual tasking. Confirmatory facto
r analysis indicated that the three target executive functions are moderate
ly correlated with one another, but are clearly separable. Moreover, struct
ural equation modeling suggested that the three functions contribute differ
entially to performance on complex executive tasks. Specifically, WCST perf
ormance was related most strongly to Shifting, TOH to Inhibition, RNG to In
hibition and Updating, and operation span to Updating. Dual task performanc
e was not related to any of the three target functions. These results sugge
st that it is important to recognize both the unity and diversity of execut
ive functions and that latent variable analysis is a useful approach to stu
dying the organization and roles Of executive functions. (C) 2000 Academic
Press.