Cerebral integration of verbal and nonverbal emotional cues: impact of individual nonverbal dominance.

Emotional communication is essential for successful social interactions. Emotional information can be expressed at verbal and nonverbal levels. If the verbal message contradicts the nonverbal expression, usually the nonverbal information is perceived as being more authentic, revealing the "true feelings" of the speaker. The present fMRI study investigated the cerebral integration of verbal (sentences expressing the emotional state of the speaker) and nonverbal (facial expressions and tone of voice) emotional signals using ecologically valid audiovisual stimulus material. More specifically, cerebral activation associated with the relative impact of nonverbal information on judging the affective state of a speaker (individual nonverbal dominance index, INDI) was investigated. Perception of nonverbally expressed emotions was associated with bilateral activation within the amygdala, fusiform face area (FFA), temporal voice area (TVA), and the posterior temporal cortex as well as in the midbrain and left inferior orbitofrontal cortex (OFC)/left insula. Verbally conveyed emotions were linked to increased responses bilaterally in the TVA. Furthermore, the INDI correlated with responses in the left amygdala elicited by nonverbal and verbal emotional stimuli. Correlation of the INDI with the activation within the medial OFC was observed during the processing of communicative signals. These results suggest that individuals with a higher degree of nonverbal dominance have an increased sensitivity not only to nonverbal but to emotional stimuli in general.