Quantitative Impact of Musical Rhythmic Complexity on Emotional State: An Empirical Study Based on Subjective Scales and Physiological Multimodal Analysis

Music, as a common artistic stimulus in daily life, has become an important research object in cognitive psychology and affective computing. This study systematically manipulates musical rhythmic complexity and simultaneously collects subjective emotional evaluation data and multimodal physiological signals to examine the quantitative influence of rhythmic complexity on emotional valence and arousal. Classical music excerpts are processed into simple, moderate, and complex rhythmic conditions, while participants’ subjective ratings, electroencephalogram signals, skin conductance, and heart rate variability are collected and analyzed. The results indicate that rhythmic complexity has a significant main effect on emotional arousal. Music with moderate rhythmic complexity induces the highest arousal level, while simple rhythmic music obtains the highest valence score. Physiological data show that skin conductance levels are significantly higher under moderate rhythmic complexity, while the LF/HF ratio of heart rate variability increases under complex rhythmic conditions. EEG analysis further shows that moderate rhythmic complexity is associated with increased frontal alpha lateralization and positive emotional experience. The study confirms a nonlinear relationship between musical rhythmic complexity and emotional state.