Mixed effects models for self-rated and objective difficulty predicted by valence and arousal ratings and random effects for video and observer.

Exact p values are shown in the brackets next to the unstandardized estimates. 95% Confidence Intervals are shown in square brackets.非标准化估计值旁的圆括号内标注了精确p值；95%置信区间（95% Confidence Interval）以方括号形式呈现。