Table 2.

Sample Characteristics of Cognitive Measures (N = 254)

Cognitive Measure	M	SD	range	n (%) Impaired
WAIS-IV
Perceptual Reasoning Index (PRI)	49.58	10.12	25–82	6 (2.36%)
Verbal Comprehension Index (VCI)	48.50	10.00	23–86	7 (2.76%)
Working Memory Index (WMI)	45.94	9.75	26–76	3 (1.18%)
Processing Speed Index (PSI)	49.76	9.59	22–73	4 (1.57%)
Trail Making Test A (TMT-A)	48.24	10.80	19–86	12 (4.72%)
Trail Making Test B (TMT-B)	49.52	9.67	23–81	2 (0.79%)

Note. All reported numbers are T-scores. Impairment is defined as a T score of < 30.