ARTICLE UPDATE - The effect of appraisal level on processing of emotional prosody in meaningless speech.

Bach DR, Grandjean D, Sander D, Herdener M, Strik WK, Seifritz E.

Neuroimage, in press

In visual perception of emotional stimuli, low- and high-level appraisal processes have been found to engage different neural structures. Beyond emotional facial expression, emotional prosody is an important auditory cue for social interaction. Neuroimaging studies have proposed a network for emotional prosody processing that involves a right temporal input region and explicit evaluation in bilateral prefrontal areas. However, the comparison of different appraisal levels has so far relied upon using linguistic instructions during low-level processing, which might confound effects of processing level and linguistic task. In order to circumvent this problem, we examined processing of emotional prosody in meaningless speech during gender labelling (implicit, low-level appraisal) and emotion labelling (explicit, high-level appraisal). While bilateral amygdala, left superior temporal sulcus and right parietal areas showed stronger blood oxygen level-dependent (BOLD) responses during implicit processing, areas with stronger BOLD responses during explicit processing included the left inferior frontal gyrus, bilateral parietal, anterior cingulate and supplemental motor cortex. Emotional versus neutral prosody evoked BOLD responses in right superior temporal gyrus, bilateral anterior cingulate, left inferior frontal gyrus, insula and bilateral putamen. Basal ganglia and right anterior cingulate responses to emotional versus neutral prosody were particularly pronounced during explicit processing. These results are in line with an amygdala-prefrontal-cingulate network controlling different appraisal levels, and suggest a specific role of the left inferior frontal gyrus in explicit evaluation of emotional prosody. In addition to brain areas commonly related to prosody processing, our results suggest specific functions of anterior cingulate and basal ganglia in detecting emotional prosody, particularly when explicit identification is necessary.

ARTICLE UPDATE - Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional pro

Hoekert M, Bais L, Kahn RS, Aleman A.

PLoS One, 3, e2244

In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half-way through the sentence.

ARTICLE UPDATE - An ERP investigation on the temporal dynamics of emotional prosody and emotional semantics in pseudo- and lexical-sentence context.

Paulmann S, Kotz SA.

Brain and Language, in press

Previous evidence supports differential event-related brain potential (ERP) responses for emotional prosodic processing and integrative emotional prosodic/semantic processing. While latter process elicits a negativity similar to the well-known N400 component, transitions in emotional prosodic processing elicit a positivity. To further substantiate this evidence, the current investigation utilized lexical-sentences and sentences without lexical content (pseudo-sentences) spoken in six basic emotions by a female and a male speaker. Results indicate that emotional prosodic expectancy violations elicit a right-lateralized positive-going ERP component independent of basic emotional prosodies and speaker voice. In addition, expectancy violations of integrative emotional prosody/semantics elicit a negativity with a whole-head distribution. The current results nicely complement previous evidence, and extend the results by showing the respective effects for a wider range of emotional prosodies independent of lexical content and speaker voice.

ARTICLE UPDATE - Early emotional prosody perception based on different speaker voices.

Paulmann S, Kotz SA.

Neuroreport, 19, 209-213

Decoding verbal and nonverbal emotional expressions is an important part of speech communication. Although various studies have tried to specify the brain regions that underlie different emotions conveyed in speech, few studies have aimed to specify the time course of emotional speech decoding. We used event-related potentials to determine when emotional speech is first differentiated from neutral speech. Participants engaged in an implicit emotional processing task (probe verification) while listening to emotional sentences spoken by a female and a male speaker. Independent of speaker voice, emotional sentences could be differentiated from neutral sentences as early as 200 ms after sentence onset (P200), suggesting rapid emotional decoding.

ARTICLE UPDATE - Cerebral processing of emotional prosody-influence of acoustic parameters and arousal.

Wiethoff S, Wildgruber D, Kreifelts B, Becker H, Herbert C, Grodd W, Ethofer T.

Neuroimage, in press

The human brain has a preference for processing of emotionally salient stimuli. In the auditory modality, emotional prosody can induce such involuntary biasing of processing resources. To investigate the neural correlates underlying automatic processing of emotional information in the voice, words spoken in neutral, happy, erotic, angry, and fearful prosody were presented in a passive-listening functional magnetic resonance imaging (fMRI) experiment. Hemodynamic responses in right mid superior temporal gyrus (STG) were significantly stronger for all emotional than for neutral intonations. To disentangle the contribution of basic acoustic features and emotional arousal to this activation, the relation between event-related responses and these parameters was evaluated by means of regression analyses. A significant linear dependency between hemodynamic responses of right mid STG and mean intensity, mean fundamental frequency, variability of fundamental frequency, duration, and arousal of the stimuli was observed. While none of the acoustic parameters alone explained the stronger responses of right mid STG to emotional relative to neutral prosody, this stronger responsiveness was abolished both by correcting for arousal or the conjoint effect of the acoustic parameters. In conclusion, our results demonstrate that right mid STG is sensitive to various emotions conveyed by prosody, an effect which is driven by a combination of acoustic features that express the emotional arousal in the speaker’s voice.

ARTICLE UPDATE - Neurology of affective prosody and its functional-anatomic organization in right hemisphere.

Ross ED, Monnot M.

Brain and Language, in press

Unlike the aphasic syndromes, the organization of affective prosody in brain has remained controversial because affective-prosodic deficits may occur after left or right brain damage. However, different patterns of deficits are observed following left and right brain damage that suggest affective prosody is a dominant and lateralized function of the right hemisphere. Using the Aprosodia Battery, which was developed to differentiate left and right hemisphere patterns of affective-prosodic deficits, functional-anatomic evidence is presented in patients with focal ischemic strokes to support the concepts that (1) affective prosody is a dominant and lateralized function of the right hemisphere, (2) the intrahemispheric organization of affective prosody in the right hemisphere, with the partial exception of Repetition, is analogous to the organization of propositional language in the left hemisphere and (3) the aprosodic syndromes are cortically based as part of evolutionary adaptations underlying human language and communication.

ARTICLE UPDATE - fMRI delineation of working memory for emotional prosody in the brain: Commonalities with the lexico-semantic emotion network

Rachel L.C. Mitchell

NeuroImage, in press

Decoding emotional prosody is crucial for successful social interactions, and continuous monitoring of emotional intent via prosody requires working memory. It has been proposed by Ross and others that emotional prosody cognitions in the right hemisphere are organized in an analogous fashion to propositional language functions in the left hemisphere. This study aimed to test the applicability of this model in the context of prefrontal cortex working memory functions. BOLD response data were therefore collected during performance of two emotional working memory tasks by participants undergoing fMRI. In the prosody task, participants identified the emotion conveyed in pre-recorded sentences, and working memory load was manipulated in the style of an N-back task. In the matched lexico-semantic task, participants identified the emotion conveyed by sentence content. Block-design neuroimaging data were analyzed parametrically with SPM5. At first, working memory for emotional prosody appeared to be right-lateralized in the PFC, however, further analyses revealed that it shared much bilateral prefrontal functional neuroanatomy with working memory for lexico-semantic emotion. Supplementary separate analyses of males and females suggested that these language functions were less bilateral in females, but their inclusion did not alter the direction of laterality. It is concluded that Ross et al.’s model is not applicable to prefrontal cortex working memory functions, that evidence that working memory cannot be subdivided in prefrontal cortex according to material type is increased, and that incidental working memory demands may explain the frontal lobe involvement in emotional prosody comprehension as revealed by neuroimaging studies.