Disentangling emotional signals in the brain: an ALE meta-analysis of vocal affect perception

Recent advances in neuroimaging research on vocal emotion perception have revealed voice-sensitive areas specialized in processing affect. Experimental data on this subject is varied, investigating a wide range of emotions through different vocal signals and task demands. The present meta-analysis was designed to disentangle this diversity of results by summarizing neuroimaging data in the vocal emotion perception literature. Data from 44 experiments contrasting emotional and neutral voices was analyzed to assess brain areas involved in vocal affect perception in general, as well as depending on the type of voice signal (speech prosody or vocalizations), the task demands (implicit or explicit attention to emotions), and the specific emotion perceived. Results reassessed a consistent bilateral network of Emotional Voices Areas consisting of the superior temporal cortex and primary auditory regions. Specific activations and lateralization of these regions, as well as additional areas (insula, middle temporal gyrus) were further modulated by signal type and task demands. Exploring the sparser data on single emotions also suggested the recruitment of other regions (insula, inferior frontal gyrus, frontal operculum) for specific aspects of each emotion. These novel meta-analytic results suggest that while the bulk of vocal affect processing is localized in the STC, the complexity and variety of such vocal signals entails functional specificities in complex and varied cortical (and potentially subcortical) response pathways.