In this paper, we used blood oxygenation level-dependent (BOLD) signals and emotion ratings to investigate the relationship between the type and strength of emotion induced by musical stimuli. Our goal was to establish a quantitative emotional evaluation method that uses brain activity. In Experiment 1, 26 participants rated 60 pieces of music using a semantic differential scale and 20 pieces were chosen on the basis of Russell's circumplex model. In Experiment 2, we investigated the relationships between the type and strength of emotion and brain activity by asking 20 participants to listen to the pieces of music in a Magnetic Resonance Imaging (MRI) scanner. We identified brain regions for which the BOLD signal intensity was correlated with the ratings of emotions. As a result, the ``Happy'' rating was mainly correlated with activity in the superior temporal gyrus. The ``Sad'' rating was correlated with activity in the left thalamus. The ``Fear'' rating was mainly correlated with activity in the parahippocampal gyrus, insular cortex, and right amygdala. By focusing on activity in these brain regions, it may be possible to quantify the type and strength of emotions evoked by music.
2017 by The Acoustical Society of Japan