The influence of emotion clarity on emotional prosody identification in paranoid schizophrenia

Abstract

Background. Identification of emotional facial expression and emotional prosody (i.e. speech melody) is often impaired in schizophrenia. For facial emotion identification, a recent study suggested that the relative deficit in schizophrenia is enhanced when the presented emotion is easier to recognize. It is unclear whether this effect is specific to face processing or part of a more general emotion recognition deficit.Method. We used clarity-graded emotional prosodic stimuli without semantic content, and tested 25 in-patients with paranoid schizophrenia, 25 healthy control participants and 25 depressive in-patients on emotional prosody identification. Facial expression identification was used as a control task.Results. Patients with paranoid schizophrenia performed worse than both control groups in identifying emotional prosody, with no specific deficit in any individual emotion category. This deficit was present in high-clarity but not in low-clarity stimuli. Performance in facial control tasks was also impaired, with identification of emotional facial expression being a better predictor of emotional prosody identification than illness-related factors. Of those, negative symptoms emerged as the best predictor for emotional prosody identification.Conclusions. This study suggests a general deficit in identifying high-clarity emotional cues. This finding is in line with the hypothesis that schizophrenia is characterized by high noise in internal representations and by increased fluctuations in cerebral networks.

Evidence for Impaired Sound Intensity Processing in Schizophrenia

“…We have argued that this could be due to enhanced noise in respective neural structures: This deficit is more pronounced for clear than for more ambiguous emotional stimuli both in the visual 37 and auditory 28 domain, as would be expected under this hypothesis. 28 Such a mechanism could also explain the present results. However, one would need to rule out some alternative explanations discussed above, such as deficits in static intensity perception or in sound source localization based on intensity.…”

“…Also, there is evidence that the prosody perception deficit in schizophrenia covaries with an impairment to extract emotional information from facial expression, 7,8,28,36 pointing toward a more general deficit in the extraction of emotional meaning from sensory information. We have argued that this could be due to enhanced noise in respective neural structures: This deficit is more pronounced for clear than for more ambiguous emotional stimuli both in the visual 37 and auditory 28 domain, as would be expected under this hypothesis.…”

“…The task lasted approximately 5-10 minutes and was preceded by a test battery for emotion perception in prosody and face expression. 28 …”

The many faces of a face: Comparing stills and videos of facial expressions in eight dimensions (SAVE database)

“…Thus, clarity is fundamental to the perception of facial expressions as well as to achieve mutual adjustment between people (e.g., Bach, Buxtorf, Grandjean, & Strik, 2009). Clarity has also been defined as referring to the reliability of the signal that permits a quick, accurate and efficient recognition of a facial expression (e.g., Tracy & Robins, 2008).…”

“…Clarity has also been defined as referring to the reliability of the signal that permits a quick, accurate and efficient recognition of a facial expression (e.g., Tracy & Robins, 2008). Clarity is therefore often inferred from the capability for accurately identifying the emotions (Bach et al, 2009). Some studies have shown that clarity judgments depend on whether the expression of a specific emotion is genuine or simulated (Gosselin, Kirouac, & Doré, 2005).…”