Table 3. Resolution of the Assertiveness × Likability interaction in the 300–450 ms time window for the anterior ROIs in Experiment 1.

Effect ofAssertiveness		Estimate	95% CI-lower	95% CI-upper	p-value
Left-anterior	low Likability	0.42	0.03	0.79	<0.06
	high Likability	−1.04	−1.72	−0.36	<0.04
Right-anterior	low Likability	−0.04	−0.46	0.39	>0.90
	high Likability	−1.08	−1.67	−0.49	<0.02

Effects of by-participant Assertiveness judgements on mean ERP amplitude differences in the Low-Likability (i.e. lower-than-median likability of the political speaker) and High-Likability (i.e. higher-than-median likability of the political speaker) groups as well as associated confidence intervals and p-values. Note that, since the by-ROI analyses reported here did not involve any random slopes, confidence intervals and p-values could be estimated using MCMC sampling [29].