Table 1. Demographic and Cognitive Variable Means, Standard Deviations, and Minimum to Maximum scores (shown in parentheses) by Total Sample and Group.

	Total	PD	Controls
Age (years)	67.99±5.03 (60-79)	67.80±5.44 (60-79)	68.18±4.64 (62-79)
Sex (n)	M=65, F=15	M=32, F=8	M=33, F=7
Education (years)	16.51±2.70 (10-22)	16.28±3.03 (10-22)	16.75±2.35 (12-20)
UPDRS Part III*	10.16± 0.87 (0-46)	17.58±10.74 (3-46)	2.75±3.36 (0-15)
DRS-2 total raw	139.81±2.84 (131-144)	139.43±3.13 (131-144)	140.20±2.49 (133-144)
DRS-2 z-score	0.18±0.73 (−1.00-1.67)	0.16±0.82 (−1.00-1.67)	0.20±0.64 (−0.67-1.67)
PS Index Score*	105.99±12.55 (79-137)	99.44±10.43 (79-122)	112.38±11.16 (93-137)
TMT B raw time*	86.84±38.78 (31-218)	103.54±44.02 (46-218)	70.14±23.18 (31-134)
TMT B z-score*	−0.03±1.03 (−1.9-2.5)	−0.48±0.94 (−1.9-1.4)	0.42±0.93 (−1.6-2.5)
BNT raw	57.18±2.84 (44-60)	56.80±3.34 (44-60)	57.55±2.21 (52-60)
BNT z-score	0.71±0.98 (−1.3-2.6)	0.65±0.97 (−1.2-2.3)	0.77±1.00 (−1.3-2.6)
Vocab raw	67.21±6.58 (47-77)	66.40±7.56 (47-77)	68.03±5.39 (55-77)
Vocab z-score	1.08±0.62 (−0.6-2.1)	1.00±0.70 (−0.6-2.1)	1.16±0.53 (−0.1-2.10)

Sample size was PD (n=40), control (n=40) unless indicated otherwise. Abbreviations: DRS-2: Dementia Rating Scale-2; UPDRS Part III: Unified Parkinson’s Disease Rating Scale, motor portion (part 3); PS Index: Processing Speed Index standardized score - note PD n=39 (due to stopwatch error); TMT B raw = Trail Making Text Part B raw time in seconds to completion; TMT B z-score = Trail Making Test Part B standardized z-score; BNT raw: Boston Naming Test raw score; BNT z-score: Boston Naming Text z-score; Vocab raw= WASI Vocabulary subtest raw score; Vocab z-score= WASI Vocabulary subtest z-score;

^*PD < Controls: p <.001