Emotional Speech Prosody Research Articles

Emotion-related acoustic communication in bats.

Some features of emotional prosody in human speech may be rooted in mechanisms common to mammals. The role of vocal communication in social interactions was studied in bats, a highly vocal group evolutionarily remote from primates. The present paper focuses on communication during agonistic encounters in the Indian False Vampire bat. Three call types with distinct time-frequency contours occurred; aggression calls, whistles, and response calls. In a first experiment, agonistic approach situations were analyzed to assess the extent to which these call types reflected the specific part of the caller in the interaction and the intensity of the agonistic display. A frame-by-frame video analysis followed by a sound analysis revealed that call type indicated the part of the respective caller while interaction intensity was encoded in similar parameter changes across call types. The systematic change in vocal parameters with affect intensity corresponded to prosodic changes in human speech. A playback experiment based on a habituation-dishabituation paradigm investigated how the bats categorized the vocalizations emitted during third-party agonistic interactions. The bats were able to discriminate between call types; however, they did not necessarily form categories corresponding to call type in reciprocal experiments, an evidence for a context-dependent evaluation of social calls.

Affect cues in vocalizations of the bat,Megaderma lyra, during agonistic interactions

Some features of emotional prosody in human speech may be traced back to affect cues in mammalian vocalizations. The present study addresses the question whether affect intensity, as expressed by the intensity of behavioral displays, is encoded in vocal cues, i.e., changes in the structure of associated calls, in bats, a group evolutionarily remote from primates. A frame-by-frame video analysis of 109 dyadic agonistic interactions recorded in approach situations was performed to categorize displays into two intensity levels based on a cost-benefit estimate. M. lyra showed graded visual displays accompanied by specific calls and response calls of the second bat. A sound analysis revealed systematic changes of call sequence parameters with display level. At the high intensity level, total call duration, number of syllables within a call, and the number of calls within a sequence were increased, while intervals between call syllables were decreased for both call types. In addition, the latency of the response call was shorter, and its main syllable-type durations and fundamental frequency were increased. These systematic changes of vocal parameters with affect intensity correspond to prosodic changes in human speech, suggesting that emotion-related acoustic cues are a common feature of vocal communication in mammals.

The effect of appraisal level on processing of emotional prosody in meaningless speech

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.

Functional contributions of the basal ganglia to emotional prosody: Evidence from ERPs

The basal ganglia (BG) have been functionally linked to emotional processing [Pell, M.D., Leonard, C.L., 2003. Processing emotional tone form speech in Parkinson's Disease: a role for the basal ganglia. Cogn. Affec. Behav. Neurosci. 3, 275–288; Pell, M.D., 2006. Cerebral mechanisms for understanding emotional prosody in speech. Brain Lang. 97 (2), 221–234]. However, few studies have tried to specify the precise role of the BG during emotional prosodic processing. Therefore, the current study examined deviance detection in healthy listeners and patients with left focal BG lesions during implicit emotional prosodic processing in an event-related brain potential (ERP)-experiment. In order to compare these ERP responses with explicit judgments of emotional prosody, the same participants were tested in a follow-up recognition task. As previously reported [Kotz, S.A., Paulmann, S., 2007. When emotional prosody and semantics dance cheek to cheek: ERP evidence. Brain Res. 1151, 107–118; Paulmann, S. & Kotz, S.A., 2008. An ERP investigation on the temporal dynamics of emotional prosody and emotional semantics in pseudo- and lexical sentence context. Brain Lang. 105, 59–69], deviance of prosodic expectancy elicits a right lateralized positive ERP component in healthy listeners. Here we report a similar positive ERP correlate in BG-patients and healthy controls. In contrast, BG-patients are significantly impaired in explicit recognition of emotional prosody when compared to healthy controls. The current data serve as first evidence that focal lesions in left BG do not necessarily affect implicit emotional prosodic processing but evaluative emotional prosodic processes as demonstrated in the recognition task. The results suggest that the BG may not play a mandatory role in implicit emotional prosodic processing. Rather, executive processes underlying the recognition task may be dysfunctional during emotional prosodic processing.

Emotional intelligence, not music training, predicts recognition of emotional speech prosody.

Is music training associated with greater sensitivity to emotional prosody in speech? University undergraduates (n = 100) were asked to identify the emotion conveyed in both semantically neutral utterances and melodic analogues that preserved the fundamental frequency contour and intensity pattern of the utterances. Utterances were expressed in four basic emotional tones (anger, fear, joy, sadness) and in a neutral condition. Participants also completed an extended questionnaire about music education and activities, and a battery of tests to assess emotional intelligence, musical perception and memory, and fluid intelligence. Emotional intelligence, not music training or music perception abilities, successfully predicted identification of intended emotion in speech and melodic analogues. The ability to recognize cues of emotion accurately and efficiently across domains may reflect the operation of a cross-modal processor that does not rely on gains of perceptual sensitivity such as those related to music training.

Vocal emotion processing in Parkinson's disease: Reduced sensitivity to negative emotions

To document the impact of Parkinson's disease (PD) on communication and to further clarify the role of the basal ganglia in the processing of emotional speech prosody, this investigation compared how PD patients identify basic emotions from prosody and judge specific affective properties of the same vocal stimuli, such as valence or intensity. Sixteen non-demented adults with PD and 17 healthy control (HC) participants listened to semantically-anomalous pseudo-utterances spoken in seven emotional intonations (anger, disgust, fear, sadness, happiness, pleasant surprise, neutral) and two distinct levels of perceived emotional intensity (high, low). On three separate occasions, participants classified the emotional meaning of the prosody for each utterance (identification task), rated how positive or negative the stimulus sounded (valence rating task), or rated how intense the emotion was expressed by the speaker (intensity rating task). Results indicated that the PD group was significantly impaired relative to the HC group for categorizing emotional prosody and showed a reduced sensitivity to valence, but not intensity, attributes of emotional expressions conveying anger, disgust, and fear. The findings are discussed in light of the possible role of the basal ganglia in the processing of discrete emotions, particularly those associated with negative vigilance, and of how PD may impact on the sequential processing of prosodic expressions.

Reduced sensitivity to prosodic attitudes in adults with focal right hemisphere brain damage

Although there is a strong link between the right hemisphere and understanding emotional prosody in speech, there are few data on how the right hemisphere is implicated for understanding the emotive “attitudes” of a speaker from prosody. This report describes two experiments which compared how listeners with and without focal right hemisphere damage (RHD) rate speaker attitudes of “confidence” and “politeness” which are signalled in large part by prosodic features of an utterance. The RHD listeners displayed abnormal sensitivity to both the expressed confidence and politeness of speakers, underscoring a major role for the right hemisphere in the processing of emotions and speaker attitudes from prosody, although the source of these deficits may sometimes vary.

Cerebral mechanisms for understanding emotional prosody in speech

Hemispheric contributions to the processing of emotional speech prosody were investigated by comparing adults with a focal lesion involving the right ( n = 9) or left ( n = 11) hemisphere and adults without brain damage ( n = 12). Participants listened to semantically anomalous utterances in three conditions ( discrimination, identification, and rating) which assessed their recognition of five prosodic emotions under the influence of different task- and response-selection demands. Findings revealed that right- and left-hemispheric lesions were associated with impaired comprehension of prosody, although possibly for distinct reasons: right-hemisphere compromise produced a more pervasive insensitivity to emotive features of prosodic stimuli, whereas left-hemisphere damage yielded greater difficulties interpreting prosodic representations as a code embedded with language content.

Affective aprosodia from a medial frontal stroke

Background and objectives. Whereas injury to the left hemisphere induces aphasia, injury to the right hemisphere’s perisylvian region induces an impairment of emotional speech prosody (affective aprosodia). Left-sided medial frontal lesions are associated with reduced verbal fluency with relatively intact comprehension and repetition (transcortical motor aphasia), but persistent affective prosodic defects associated with right medial frontal lesions have not been described. Methods. We assessed the prosody of a man who sustained a right medial frontal cerebral infarction seven years prior. Results. While propositional speech expression was normal including syntactic prosody, the patient was impaired at expressing emotions using prosody. His comprehension and repetition of prosody were also impaired but less so than expression. Conclusions. Right medial frontal lesions can induce an affective aprosodia that primarily impairs expression.