Table 2.

Hierarchical Multiple Regression Models Predicting Negative Urgency and PASAT-C Quit Time from Neuroticism, Pre-Ejection Period, and their Interactions (N=194)

	Outcome
Parameter	Negative Urgency		PASAT Quit Time+
	B		B
	Model 1	Model 2	Model 1	Model 2
Step 1
Female Sex++	--	--	0.21**	0.20**
Neuroticism (N)	0.49***	0.99***	0.12	0.49
Baseline PEP	−0.13*	−0.14*	0.03	0.02
Step 2
N × Baseline PEP		−0.52*		−0.38
R2 Δ		0.02*		0.011
Model R2	0.26***	0.28***	0.054*	0.065*

Note:

^*p < .05

^**p < .01

^***p < .001

PEP = Cardiac Pre-ejection Period; lower PEP scores indicate higher levels of sympathetic nervous system activation. PASAT = Paced Auditory Serial Addition Task.

⁺Variable was created by log transforming the time spent in level 3 of the PASAT and inverting values so that higher scores reflect greater impulsive behavior.

⁺⁺To reduce unnecessary error in estimates, female sex was only included in models where it demonstrated significant zero-order correlations with other included variables; however, patterns of significant findings remained the same female sex was included in other models.