Evolutionary perspectives on emotions and their link to intentions, dispositions and behavior: Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al

Vocal Expression of Affective States in Spontaneous Laughter reveals the Bright and the Dark Side of Laughter

It has been shown that the acoustical signal of posed laughter can convey affective information to the listener. However, because posed and spontaneous laughter differ in a number of significant aspects, it is unclear whether affective communication generalises to spontaneous laughter. To answer this question, we created a stimulus set of 381 spontaneous laughter audio recordings, produced by 51 different speakers, resembling different types of laughter. In Experiment 1, 159 participants were presented with these audio recordings without any further information about the situational context of the speakers and asked to classify the laughter sounds. Results showed that joyful, tickling, and schadenfreude laughter could be classified significantly above chance level. In Experiment 2, 209 participants were presented with a subset of 121 laughter recordings correctly classified in Experiment 1 and asked to rate the laughter according to four emotional dimensions, i.e., arousal, dominance, sender’s valence, and receiver-directed valence. Results showed that laughter types differed significantly in their ratings on all dimensions. Joyful laughter and tickling laughter both showed a positive sender’s valence and receiver-directed valence, whereby tickling laughter had a particularly high arousal. Schadenfreude had a negative receiver-directed valence and a high dominance, thus providing empirical evidence for the existence of a dark side in spontaneous laughter. The present results suggest that with the evolution of human social communication laughter diversified from the former play signal of non-human primates to a much more fine-grained signal that can serve a multitude of social functions in order to regulate group structure and hierarchy.

Effects of cue modality and emotional category on recognition of nonverbal emotional signals in schizophrenia

BACKGROUND

Impaired interpretation of nonverbal emotional cues in patients with schizophrenia has been reported in several studies and a clinical relevance of these deficits for social functioning has been assumed. However, it is unclear to what extent the impairments depend on specific emotions or specific channels of nonverbal communication.

METHODS

Here, the effect of cue modality and emotional categories on accuracy of emotion recognition was evaluated in 21 patients with schizophrenia and compared to a healthy control group (n = 21). To this end, dynamic stimuli comprising speakers of both genders in three different sensory modalities (auditory, visual and audiovisual) and five emotional categories (happy, alluring, neutral, angry and disgusted) were used.

RESULTS

Patients with schizophrenia were found to be impaired in emotion recognition in comparison to the control group across all stimuli. Considering specific emotions more severe deficits were revealed in the recognition of alluring stimuli and less severe deficits in the recognition of disgusted stimuli as compared to all other emotions. Regarding cue modality the extent of the impairment in emotional recognition did not significantly differ between auditory and visual cues across all emotional categories. However, patients with schizophrenia showed significantly more severe disturbances for vocal as compared to facial cues when sexual interest is expressed (alluring stimuli), whereas more severe disturbances for facial as compared to vocal cues were observed when happiness or anger is expressed.

CONCLUSION

Our results confirmed that perceptual impairments can be observed for vocal as well as facial cues conveying various social and emotional connotations. The observed differences in severity of impairments with most severe deficits for alluring expressions might be related to specific difficulties in recognizing the complex social emotional information of interpersonal intentions as compared to "basic" emotional states. Therefore, future studies evaluating perception of nonverbal cues should consider a broader range of social and emotional signals beyond basic emotions including attitudes and interpersonal intentions. Identifying specific domains of social perception particularly prone for misunderstandings in patients with schizophrenia might allow for a refinement of interventions aiming at improving social functioning.