| Schizophrenia is a common and serious disease in psychology. Now, the studies in schizophrenic symptomatology have transited from negative/positive dichotomy in 1980s to cognitive disorder. A number of studies have found that cognitive deficits are a group of syndromes independent from the positive and negative dimension and contribute directly to impaired social functioning. There are many studies on cognitive function in schizophrenia those focused on the biological mechanism of cognition. So we explore the relationship between P300 and cognitive disorder in neuroelectrobiology. P300 is a kind of brain e-voked potential ( BEP) which is related to cognitive process. The P300 component of the auditory event-related brain potential ( ERPs) is consistently reduced in schizophrenia. However, reports of correlation between P300 amplitude and clinical symptoms are inconsistent. A number of previous studies have concluded the relationship between them on the basis of a positive and negative dichotomy, but, such a dichotomy has been criticized. Now many studies have applied factor analytic techniques to extract cognitive deficit factor. In order to clarify the clinical significance of the P300 component as a biological marker that can reflect schizophrenic symptomatology. In the present study, we explore the relationship between P300 amplitude and cogni-tive disorder factor.Material and methodsPatients: sixty-three consenting patients ( men, n = 33; women, n =30) fulfilling ICD-10 criteria for schizophrenia or schizophreniform disorder were recruited from mental hospital and mental clinic for the first meeting. The sample was collected from July, 2001 to December, 2001. Regarding handedness: sixty patients were right-handed, two were mixed-handed and one had left-handed. There mean age was 23.46 ?.02years (range 16 -42years) , their mean education level was 12.05 ?.46years ( rangeS - ITyears) and their mean duration of illness was 8. 20 ?5. 38 months ( range 11 days-17months). All patients were drug-naive and had no ECT. Only patients without mental retardation, brain organic psychosis and psychosis caused by physical diseases were included. In addition, patients who had current abuse and past dependence on alcohol or drugs were excluded. At the same time, patients and control subjects were excluded for a history of head injure resulting in loss of consciousness greater than 30 minutes, hearing deficits greater than30dB at 1000, 2000Hz in their better ear. The Positive and Negative Scale (PANSS) was over 60.Health controls: Forty volunteers ( men, n = 19; women, n = 21) were recruited as controls. They had no significant physical and/ or mental illness, alcohol or drug abuse and/or a history of major mental disorder among their first degree relatives. The sample was established at the same time of patients. Their mean age was 21. 70 ?6.22years (range 16 -38years) , their mean education level was 12. 10 2. 71years ( rangeS - 18years). About handedness, 38 volun-teers were right-handed, one was mixed-handed and one had left-handed.Assessment of Psychopathology; In the present study, we selected the Positive and Negative Scale (PANSS) to access the psychopa-thology in the schizophrenia.ERPs ( P300) recording procedures: we used Denmark KeyPoint Evoked Potentials instrument. According to the international 107 20 systems, ERPs were recorded with needle electrodes located at Fz, Cz, Pz, T3. ERPs were collected during auditory Ts/NTs stimulus paradigm (" oddball" paradigm) target detection task that frecpient tones occurred on 80% of the trials and target tones occurred on 20% of the trials.Statistical analysis; T-test, factor analysis and Pearson correlation are carried out with the soft of SPSS in the present study.ResultsIn the present study, the principal component analysis of the PANSS items revealed five factors including the cognitive disorder, negative, depression, hostile/excitable, delusion/hallucination .In the trials, the amplitude of P300 recorded at Fz, Cz, Pz... |
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