Effects of prosodic emotional intensity on activation of associative auditory cortex.

Functional magnetic resonance imaging was used to investigate hemodynamic responses to adjectives pronounced in happy and angry intonations of varying emotional intensity. In separate sessions, participants judged the emotional valence of either intonation or semantics. To disentangle effects of emotional prosodic intensity from confounding acoustic parameters, mean and variability of volume and fundamental frequency of each stimulus were included as nuisance variables in the statistical models. A linear dependency between hemodynamic responses and emotional intensity of happy and angry intonations was found in the bilateral superior temporal sulcus during both tasks, indicating that increases of hemodynamic responses in this region are elicited by both positive and negative prosody independent of low-level acoustic properties and task instructions.