Table 3.

Univariate comparisons for PD subgroup performance based on logistic regression analysis

	PD (N = 24) (Mean/SD)	PD/NC (N = 8) (Mean/SD)	t-value
Age	68.7/6.7	61.5/10.1	−2.30*
Age at PD Dx	63.8/8.1	55.8/9.3	−2.37*
Education	14.8/2.7	17.0/2.4	2.04*
Beck Depression Inventory	9.0/6.0	3.8/4.2	−2.32*
Brief Test of Attention	16.6/1.7	18.4/1.8	2.51*
Purdue Pegboard (right)	8.7/2.5	11.1/3.7	2.13*
Purdue Pegboard (bilateral)	6.4/1.7	8.1/2.4	2.28*
Spatial Span Backwards	4.6/1.6	6.8/1.7	3.22**
Petrides Conditional Associate Learning (no. trials to criterion)	64.7/8.0	45.9/21.5	−3.68**
Petrides Conditional Associate Learning (no. errors)	52.2/22.2	17.3/9.1	−4.28**
Digit Span Backwards	5.2/1.5	7.3/1.8	3.15**
Executive Dysfunction. Scale	38.2/9.7	24.4/2.8	−3.91**
Odd Man Out Test	28.4/5.9	37.1/1.6	4.11**

^*p < .05;

^**p < .001.

PD/NC = PD participants classified as NC by logistic regression analysis.