Psychological and brain mechanisms of the production and the decoding of voice melodies
A CRBLM Distinguished Lecture
The decoding of emotion in vocal productions is an essential ability of non-human animals and humans for survival and for social interactions. The brain processes underlying this competency include several steps of information processing including the basic auditory decoding, the organization of auditory stream to perceive an auditory object, and the attributions of emotional characteristics of the vocal production perceived. The building up of an emotional auditory object necessitates the interactions of different brain regions involved in the decoding process including primary and secondary auditory regions, i.e. the voice area in humans, amygdala, frontal regions such as the inferior and orbito-frontal regions and basal ganglia. How these brain regions interact together is a crucial question to resolve to have a better understanding of emotional information processing in human brain. The involvement of secondary auditory regions, amygdala, basal ganglia and frontal regions, as well as their interactions, has been investigated using functional magnetic resonance imaging (fMRI) and local field potentials (LFPs) recorded using macroelectrodes in human candidates to neurosurgery for intractable epilepsy or for Parkinson’s disease. FMRI analysis, psychophysiological interactions and dynamic causal modeling revealed the connectivity between the different brain regions subserving emotional auditory information processing. The LFP results revealed complex patterns of the neuronal dynamics through neuronal synchronization measures in low and high frequencies between amygdala and the medial part of OFC during the decoding of emotional prosody. Recent studies investigating the brain mechanisms involved in the production of emotional prosody will be also discussed, especially the involvement of the basal ganglia. I will also discuss the links between emotional prosody and music. The convergence of the results obtained in the decoding and production of emotional prosody using different brain imaging and brain damaged patient studies increases our knowledge about emotions and theirs status in the human mind.
Didier Grandjean is an associate professor in the Department of Psychology and Educational Sciences, as well as a member of the Swiss Center for Affective Sciences, at the University of Geneva. He achieved his thesis in 2005 under the direction of Klaus Scherer about the dynamics of appraisal processes using electroencephalographic methods. He has published more than 60 peer review articles in international scientific journals in psychology and neuroscience about emotional processes related to emotional prosody perception and production, appraisal processes, the emergence of feelings, music and emotion, olfaction and emotion, and emotional facial expression perception and production.