Table 4.

Hierarchical multiple linear regression model for the dual conflict effect in PD.

	coefficients				model statistics						power
	B	β	t	p	R2	Δ R2	Δ F	sig. Δ F	Model Fit F	Model Fit p	1−β
step 1 model					.06	.06.	8.28	.005	8.28	.005	.83
constant	.00		.00	1.000
age	.24	.24	2.88	.005
step 2 model					.12	.06	3.09	.029	4.49	.002	.94
constant	.00		.00	1.000
age	.17	.17	1.99	.049
caudate DVR	−.17	−.17	−1.97	.051
thalamic k3	.00	.00	.01	.989
cortical k3	−.16	−.16	−1.52	.131
step 3 model					.15	.03	4.69	.032	4.63	.001	.97
constant	−.05		−.56	.574
age	.15	.15	1.81	.073
caudate DVR	−.24	−.24	−2.60	.010
thalamic k3	.01	.01	.07	.943
cortical k3	−.14	−.14	−1.35	.180
caudate DVR * cortical k3	.18	.19	2.17	.032

(N = 135, all PD patients with both the DTBZ and PMP PET measures). All variables standardized before being entered in the model. B, unstandardized coefficient; β, standardized coefficient.

^**indicates p < .0005