The Influence of Negative Emotion to Cortical Activity Induced by Auditory Verbal Imagery / 신경정신의학

OBJECTIVE: The concern about auditory verbal imagery has increased due to its possible relationship with auditory hallucinations. The research on auditory hallucinations was activated in accordance with the advance of neurophysiologic and functional neuroimaging studies, and the relationship between auditory verbal imagery and auditory hallucination was also investigated with neuroscientific methods. In particular, the group of neuropsychiatrists who insisted that auditory hallucination results from the abnormality of self monitoring systems has attempted to document the relationship between auditory verbal imagery and auditory hallucination using brain activation studies. Most auditory hallucinations are derogatory in content and accompany negative emotions. If auditory verbal imagery plays an important role in the pathogenesis of auditory hallucination, then it must be influenced by negative emotions. This study was aimed to examine the hypotheses that negative emotions have influence on cortical activity provoked by auditory verbal imagery and that the area which is influenced by negative emotions is where it is regarded to be related to either auditory hallucinations or self monitoring systems. METHOD: To examine these hypotheses, quantitative electroencephalography (Q-EEG) was applied during the auditory verbal imagery tasks using a two word list. The one word list accompanied negative emotion and the other accompanied neutral emotions, and they were suggested to the subject via computer monitor system. Total 18 right handed normal subjects(11 male subjects and 7 female subjects) were enrolled. RESULTS: The difference of EEG amplitude between during the baseline task and during auditory verbal imagery task using neutral word list: there were no significant difference in all electrode and all alpha, beta, theta, and delta frequency bands. The difference of EEG amplitude between during the baseline task and during auditory verbal imagery task using negative word list: In alpha frequency band, the EEG amplitude was increased in bilateral parietal, bilateral posterior temporal and bilateral occipital area. In beta frequency band, the EEG amplitude increased in bilateral parietal, bilateral occipital and left posterior temporal area. In theta frequency band, the EEG amplitude increased in TT2, T5, T6. In delta frequency band, there were no significant differences. The difference of EEG amplitude between during the two auditory verbal imagery tasks using negative word list and neutral word list: In alpha frequency band, there was an increasing trend in TT1 and a decreasing trend in frontal area including F4 during the negative auditory verbal imagery in EEG amplitude, although statistically not significant. In beta frequency band, EEG amplitude was increased in temporal area such as TCP1. In addition, there was an increasing trend in T5 in EEG amplitude, although statistically not significant. In theta frequency band, the EEG amplitude was decreased in the right hemisphere areas such as FP2, F4, C4, CP2, P4. In delta frequency band, there were no significant differences. CONCLUSION: In summarizing the above results, left temporal area was more activated during auditory verbal imagery using negative word list than using neutral word list. Left temporal area is known to play an important role in self monitoring systems and left temporal abnormality has been observed in schizophrenic patients in many studies. According to the above results, during auditory verbal imagery with negative emotion, more activation in left temporal area is necessary, but that may not achieved in schizophrenia patients. So, the possibility that the resultant disturbance of self monitoring system may be related to auditory hallucination is suggested in this study.

The Influence of Negative Emotion to Cortical Activity Induced by Auditory Verbal Imagery in Patients with Schizophrenia

OBJECTIVES: Cognitive psychological models propose that auditory hallucinations arise from a problem with monitoring one's auditory verbal imagery. Most auditory hallucinations are derogatory in content and accompany negative emotions. If auditory verbal imagery plays an critical role in the pathogenesis of auditory hallucination, it must be influenced by negative emotions. This study was aimed at understanding the influence of negative emotions on the development of hallucinations by investigating the way by which negative emotions have influence on cortical activity induced by auditory verbal imagery. METHODS: For both normal subjects and patients with schizophrenia, quantitative electroencephalography(Q-EEG) was applied during the auditory verbal imagery tasks using a two word list. The one word list accompanied negative emotion and the other accompanied neutral emotions. The difference of EEG activity between two tasks was compared by paired t-test. WE also compare the difference of the influence of negative emotions between normal subjects and patients with schizophrenia. RESULTS: In normal subjects, amplitude of beta wave was increased in temporal area such as TCP1, and, the amplitude of theta frequency wave was decreased in right hemisphere such as FP2, F4, C4, CP2, P4, But, in the schizophrenia group, there were no significant differences. CONCLUSION: These results may suggest that auditory verbal imagery with negative emotion requires more activation in left temporal area, but, appropriate activation may not achieved in schizophenia patients. So, the possibility that the resultant disturbance of verbal self monitoring may be related to auditory hallucination is suggested in this study.