Table 3.

Brain activation differences for SST “saliency” contrast analysis (i.e., stop > go trials) between groups, including paired t-test comparison of participants with PD in their “ON” versus “OFF” medication state (Medication effects) and 2-sample t-test comparison of participants with Parkinson’s disease in their “OFF” medication state versus controls (disease effects)

Contrast	Cluster size (mm3)	p-value (FWE corrected)	t-score	MNI coordinates (mm)			Identified regions
				X	Y	Z
ON > OFF (medication effect)
Stop > Go	5828	0.044	6.47	20	0	−12	R striatum, R thalamus, R insula, R IFG
			6.08	16	−12	10
			5.19	16	−27	8
CTL > OFF (disease effect)
Stop > Go	6764	0.039	5.07	23	3	−18	R striatum
			4.69	23	8	−22
			4.55	13	10	0

Task contrast results have a cluster-forming threshold of p < 0.005, with a nonparametric p < 0.05 FWE cluster correction, using SnPM13.

Key: CTL, control; FWE, family-wise error; IFG, inferior frontal junction; MNI, Montreal Neurological Institute; R, right.