OBJECTIVE: Listening to Mozart K.448 has been demonstrated to improve spatial 
task scores, leading to what is known as the Mozart Effect. However, most of 
these reports only describe the phenomena but lack the scientific evidence 
needed to properly investigate the mechanism of Mozart Effect. In this study, we 
used electroencephalography (EEG) and heart rate variability (HRV) to evaluate 
the effects of Mozart K.448 on healthy volunteers to explore Mozart Effect.
DESIGN: An EEG-based post-intervention analysis.
SETTING: Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
PARTICIPANTS: Twenty-nine college students were enrolled. They received EEG and 
electrocardiogram examinations simultaneously before, during and after listening 
to the first movement of Mozart K.448.
MAIN OUTCOME MEASURE: EEG alpha, theta and beta power and HRV were compared in 
each stage.
RESULTS: The results showed a significant decrease in alpha, theta and beta 
power when they listened to Mozart K.448. In addition, the average root mean 
square successive difference, the proportion derived by dividing NN50 by the 
total number of NN intervals, standard deviations of NN intervals and standard 
deviations of differences between adjacent NN intervals showed a significant 
decrease, while the high frequency revealed a significant decrease with a 
significantly elevated low-frequency/high-frequency ratio.
CONCLUSION: Listening to Mozart K.448 significantly decreased EEG alpha, theta 
and beta power and HRV. This study indicates that there is brain cortical 
function and sympathetic tone activation in healthy adults when listening to 
Mozart K.448, which may play an important role in the mechanism of Mozart 
Effect.