Table 1.

Cognitive Characteristics of the Sample

Cognitive Assessment	Mean	SD
MMSE (maximum 30)	26.9	3.3
Digit symbol substitution (number correct in 90 s)	32.6	8.9
Digit symbol copy (time in seconds to complete)	146.5	48.5
Backward digit span (maximum 14)	4.9	1.6
Digit ordering (maximum 24)	12.6	4.0
WAIS vocabulary (maximum 70)	53.6	13.6
Stroop test (total correct; baseline minus interference)	22.1	9.5

Abbreviations: SD, standard deviation; MMSE, Mini Mental State Examination; WAIS, Wechsler Abbreviated Scale of Intelligence.