| In the world, about1in every100persons would develop schizophrenia in their lifetime, and the patients with schizophrenia often end in poor social functioning, which would bring a heavy burden on the patients' family and society. It's significant to do the research about the mechanism of the poor social functioning in schizophrenia since there was no fundamental solution for the disease.Recent findings have shown that deficits in social cognition, especially dificit in emotional percetion play an important role in the poor social functioning in schizophrenia, and the deficit in emotional perception in schizophrenia was considered as a key factor to predict the patient's social functional outcome. However, there were a series of issues regarding the deficit that remain to be clarified, such as the potential neural basis, the processing stage and invovled emotions for the deficit. The present study tried to explore the dynamic cognitive processing of the emotional cues from face, voice and audiovisual stimuli in schizophrenia. In the study, event-related potentials (ERPs) techinique was exploited for its high temporal resolution. Using the ERPs components to index the emotional percertion impairment in schizophrenia, thus the study would help us to understand the potential mechanism of the deficit in social cognition in schizophrenia and would provide the empirical evidence for the patient's future treatment strategies.Part I The processing of face and facial emotion in schizophrenia-the ERPs studyObjective:Despite the evidence that show the deficits in facial and facial expression processing in schizophrenia, the issues regarding the cognitive stage for the deficits occurring and the relationship of the deficts remain unclear. The precent part I study attempt to explore the underlying cognitive processing stages for face and facial expression in schizophrenia.Methods:Twenty patients with schizophrenia (SZ group) and20normal healthy controls (NC group) participated in the experiment and64channel EEG/ERPs responses were recorded when the participants operated a facial categorization task. Participants viewed to angry, happy, and neutral human faces, as well as to primate faces, which served as a response target. The human faces with different expressions established angry (Ang), Happy (Hap) and Neutral (Neu) three conditions, and the ERPs to primate face would not followed further analysis, since they just used as targets, which would keep the participant's attention retaining on the experiment and avoid ERPs to human's face contaminated by the motor response.Results:The changing tendencies of ERPs waveforms to face in NC and SZ were similar. N100, P200, N250, P300components were observed at electrodes in the frontal-central region, while P100, N170, P270were observed at electrodes in the parietal-occipital region. Ombus-MANOVAs yielded a main effect of group on the amplitudes of N170, N250and P300, specifically, SZ subjects had an attenuated N170and P300, but an enhanced N250relative to NC. The data also underwent a following pairwise-comparisions analysis, and results showed the patient's N170dicrease occurred in Ang and Neu, not Hap condition, N250enhancement only in Hap condition, and P300discrease in Neu condition.Conlusion:1) schizophrenia patients'deficits in emotion percetion are due to deficits in structural encoding of facial features, and the latter deficits may related to the impairment of facial identification at late stage in SZ, especially for neutral face.2) Deficits in facial emotional perception in SZ may be specific to negative emotion, for example, angry. Part â…¡ The processing of human voice prosody in schizophrenia-the ERPs studyObjective:The deficits in prosody perception in SZ were preliminarily constructed, however, the studies on the processing of prosody in SZ were relative sparse, and the issues regarding the cognitive stage for the deficits occurring and the relationship of the deficts remain unclear. The precent part â…¡ study attempt to explore the underlying cognitive processing stages for human voice prosody in schizophrenia.Methods:With the exception of stimuli and subject's task, the methods in this part were same as that in Part â… study. Nonverbal angry (Ang), Happy (Hap) and Neutral (Neu) vocalization or primate's voices was displayed to subjects, and the participants were required to press a button when they heard any primate voice.Results:The changing tendencies of ERPs waveforms in NC and SZ were similar. N100, P200components were observed at electrodes in the frontal-central region, while no distinct ERP response was observed at electrodes in the parietal-occipital region. Ombus-MANOVAs yielded a main effect of condition on the amplitudes of N100and P200, also on the latency of N100. Specifically, relative to Neu condition, emotional conditions (both Ang and Hap) elicited an early and decreased N100, and an enhanced P200. Following pairwise-comparisions showed the condition effect in SZ was not as obvious as in NC.Conlusion:1) These results suggested facilitating effects of emotion carried by nonlinguistic emotional sounds on early stages of processing as evident in both N100and P200results, and the facilitating effect was not dependent on valence.2) SZ showed a subtle impairment in the ability to take advantage of emotional cues in nonverbal vocalization. Partâ…¢ The multisensory integration of emotional cues from face and voice in schizophrenia-the ERPs studyObjective:Most events in the natural environment generate stimulation to several modalities, which requires the brain to integrate a variety of different inputs from sense organs into a single percept of the situation. This processing to integrate multisensory information was called as multisensory integration (MSI), and drew more and more attention in the neurocognitive science. Normally, human and animal alike effectively take advantage of MSI to enhance the perception and speed the response to the events. The research on the MSI in SZ is only on its infancy, and the nature, impaired cognitive stage and span for the MSI deficit in SZ were far from understood. The present study was tried to explore the underlying cognitive processing stages for the emotional audiovisual stimuli MSI in schizophrenia.Methods:With the exception of stimuli and subject's task, the methods in this part were same as that in Part â… study. The stimuli in this part were the combination of face and voice basing on emotion congruency.Results:The changing tendencies of ERPs waveforms to audiovisual stimuli were similar to that in the Part I study. N100, P200, N250, P300components were observed at electrodes in the frontal-central region, while P100, N170, P270were observed at electrodes in the parietal-occipital region. Ombus-MANOVAs yielded a main effect of condition on the amplitudes of P200, P300and N250. Specifically, emotional condition (both Ang and Hap) elicited a decreased N250, an enhanced P200and P300. Following pairwise-comparisions showed the condition effect in SZ was not as obvious as in NC.Conlusion:1) The general effect of emotion on audiovisual processing can emerge as early as200msec post stimulus onset, in spite of implicit affective processing task demands, and that such effect is mainly distributed in the frontal-central region.2) The emotion effect is not dependent on valence.3) The subtle impairtment to extract emotion salience in SZ not only occured in auditory modality but also in audiovisual modality. |
PDF Full Text Request