On the lateralization of emotional prosody: An event-related functional MR investigation

Abstract

In order to investigate the lateralization of emotional speech we recorded the brain responses to three emotional intonations in two conditions, i.e., ''normal'' speech and ''prosodic'' speech (i.e., speech with no linguistic meaning, but retaining the Ôslow prosodic modulationsÕ of speech). Participants listened to semantically neutral sentences spoken with a positive, neutral, or negative intonation in both conditions and judged how positive, negative, or neutral the intonation was on a five-point scale. Core peri-sylvian language areas, as well as some frontal and subcortical areas were activated bilaterally in the normal speech condition. In contrast, a bilateral fronto-opercular region was active when participants listened to prosodic speech. Positive and negative intonations elicited a bilateral fronto-temporal and subcortical pattern in the normal speech condition, and more frontal activation in the prosodic speech condition. The current results call into question an exclusive right hemisphere lateralization of emotional prosody and expand patient data on the functional role of the basal ganglia during the perception of emotional prosody.

Processing of emotional vocalizations in bilateral inferior frontal cortex

“…These results together suggest that both the left and the right IFC are involved in the processing of emotional value from voices with no clear laterality effects (Kotz et al, 2003). Summarizing the peak activations across all fMRI and PET studies on processing emotional vocalizations provides a clear picture for a bilateral distribution of peak activation (see Fig.…”

“…Recent neuroimaging studies found several right IFC peak activations distributed from the posterior to the anterior IFC located in BA 44 Kotz et al, 2003), BA 45 (Bach et al, 2008;Beaucousin et al, 2007;Ethofer et al, 2006;Sander et al, 2005), and BA 47 (Bach et al, 2008;Beaucousin et al, 2007;Belin et al, 2008a;Ethofer et al, 2009;Mitchell, 2006;Sander et al, 2005), as well as in the fOP Kotz et al, 2003;Mitchell et al, 2003;Schirmer et al, 2004) (see Fig. 2).…”

“…However, it has been suggested that the left compared with the right IFC has only a supplementary processing role, such as prosody-related working memory processes Wildgruber et al, 2005), linguistic processing (Buchanan et al, 2000;Wildgruber et al, 2004), retrieval of semantic knowledge (Beaucousin et al, 2007), or semantic processing during impaired prosody processing (Mitchell, 2006;Schirmer and Kotz, 2006;Schirmer et al, 2004). Nonetheless, even when controlling for all secondary and language-related task effects, emotional vocalizations still elicit activity in the left IFC Kotz et al, 2003;Leitman et al, 2010;Sander et al, 2005). Furthermore, the left IFC is active in response to nonverbal expressions without any language-related features (Belin et al, 2008a;Fecteau et al, 2005;Morris et al, 1999).…”

“…However, it seems that the medium of vocal expressions as a bottom-up factor can also influence this peak distribution. Concerning this medium or nature of vocalizations, vocal expressions of emotions can be purely nonverbal, such as laughs, cries, or screams (Sauter et al, 2010;Simon-Thomas et al, 2009), but they can also be superimposed on semantically neutral Kotz et al, 2003;Leitman et al, 2010) and semantically emotional language (Beaucousin et al, 2007;Mitchell, 2006;Mitchell et al, 2003;Schirmer et al, 2004), as well as on pseudospeech (Bach et al, 2008;Sander et al, 2005). Given this distinction between nonverbal vocal expressions and emotional prosody, it might be assumed that emotional intonations superimposed on speech strongly engage the left IFC, whereas nonverbal expressions activate the right IFC (Meyer et al, 2005).…”

“…First, many recent studies found bilateral (Beaucousin et al, 2007;Ethofer et al, 2006;Kotz et al, 2003;Morris et al, 1999) or even specific left IFC activity (Bach et al, 2008;Fecteau et al, 2005;Mitchell, 2006;Wildgruber et al, 2004) in response to emotional prosody in several subregions of the IFC (see Fig. 2).…”