Multimodale Integration bei Menschen mit erhöhtem Psychoserisiko

Schizophrenic patients seem to have deficits in encoding emotional expressions while integrating emotionally valenced crossmodal sensory stimuli. In this study the influence of olfactory stimuli on the discrimination of emotional facial expressions in individuals with high risk for psychosis and healthy controls was examined. Participants were asked to discriminate happy, disgusted or neutral facial expressions, while being exposed to unirhinal stimulation with pleasant, unpleasant or neutral odors. Facial expressions and olfactory stimuli were joined in all nine possible combinations. Subsequently accuracy and reaction times were compared. The used odors were evaluated by the participants regarding their affective valence and their intensity. Additionally a test of smell identification ability was applied. The participants of both groups did not differ significantly in their ability of smell identification or in the evaluation of the odors. The vanilla scent, used as pleasant odor was rated less intense than the unpleasant sulphur scent. In both groups, classification of disgusted facial expressions was more accurate during stimulation with the unpleasant odor and faster during stimulation with the pleasant odor compared to the neutral olfactory condition. This indicates facilitated recognition of disgust in the presence of olfactory stimulation as postulated along with the results of prior studies. In the high-risk group reaction times for classification of the emotional facial expressions were overall higher, yet there was no difference in discrimination accuracy between both groups nor interaction effects with the specific type of facial expression. The increased reaction times might indicate a reduced speed of information processing, which was also expressed by a neuropsychological test on this domain. In conclusion, the results of the present study do not explicitly point to a specific deficit in the recognition of emotional expressions under stimulation with emotionally valent olfactory cues in individuals with an elevated risk of psychosis