| Experiment 1:A study of the relationship between the damage of self-source monitoring and symptomatology in male patients with schizophreniaObjective: To investigate if male schizophrenic patients had damage of self-source monitoring , as well as whether the damage was related to delutions or negative symptoms.Methods: 20 male patients with schizophrenia (including 10 cases with delutions, 10 cases with negative symptoms) as study group and 20 normal subjects as control group. Patients with schizophrenia were assessed with Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS). All subjects were given source memory task and then recorded the number of correct response item, followed by Stroop color word test which was used to test the performance of selective attention. Calculated false alarms rate, missing rate, correct source score, memory score, identify index Pr, response bias index Br and the indicators of selective attention. Two sample t-test was used in comparison between patient group and control group. Using analysis of variance (ANOVA) compared to each other among delutions subgroup and negative symptoms subgroup of schizophrenia and control group. Pearson related analysis was used in patient group with the indicators of selective attention, symptom score and memory score, as well as the identify index Pr of source monitoring.Results:1. The false alarms rate and miss rate in patient group were higher than control group (P<0.05), and correct source score, memory score, identify index Pr, response bias index Br and the indicators of selective attention in patient group were lower than control group, and the difference between two groups was statistically significant (P<0.05).2. The false alarms rate and miss rate in delutions subgroup were higher than negative symptoms subgroup and control group (P<0.05), correct source score, memory score, identify index Pr, response bias index Br and the indicators of selective attention in delutions subgroup were lower than control group (P<0.05). There was no significant difference in correct source score and the indicators of selective attention between the delutions subgroup and negative symptoms subgroup (P>0.05).3. There was no significant difference in the various indicators of source monitoring between negative symptoms subgroup and control group (P>0.05). But the performance of selective attention in negative symptoms subgroup was lower than control group (P<0.05).4. Pearson related analysis showed that the performance of selective attention had correlation with the performance of the source monitoring and memory score (P<0.05), but had no correlation with the symptom score (P>0.05). Conclusion: Overall male schizophrenic patients have damage in the performance of self-source monitoring and selective attention ,and the damage in self-monitoring is close to delutions symptoms rather than negative symptoms, which is a prompt that different symptoms of schizophrenic patients can arise from different mechanisms, damage in self-monitoring may be the base of delutions symptoms.The performance of selective attention is associated with the damage of the source monitoring, suggesting that it may be involved in the identification processing about self-source information. Experiment 2: A control study of magnetoencephalography about external source monitoring in male patients with schizophreniaObjective: To explore if the ability of external source monitoring in male patients with schizophrenia was impaired by using magnetoencephalography, as well as its neural mechanisms.Methods: 10 male patients with schizophrenia, 10 normal control subjects were showed pictures of physical two-word, which was printed in red or green color. After the study phrase, all subjects were asked to complete a further understanding of recognition memory task (the new /old judgment) and external source memory task (red or green). At the same time the evoked magnetic fields (EFs) generated by the subjects'head were recorded by the MEG mission equipment. Underwent the second scanning using magnetic resonance imaging (MRI), the images of the heads of 20 subjects were carried out. MEG data collected would be superimposed to the images of MRI, then the magnetic source imaging (MSI) data would be required. Employed the SAM (synthetic aperture magnetometry) analysis, and required respectively the activated points of brain areas in two tasks of two groups. Recorded the SAM value and the number of the same activated points of brain areas, two sample t-test and chi square test were used in inter-group comparison. The behavioral data of subjects recorded by computer were calculated as identify index Pr in recognition memory task and accuracy of source memory I in external source memory task, two sample t-test was used in inter-group comparison. Results:Behavioral data: The behavioral data showed that in comparison with healthy participants, identify index Pr of recognition memory task and accuracy of source memory I of external source memory task of the patients group were significantly lower.[Pr for(0.60±0.13),t = 2.76, P<0.05; I for (0.61±0.15),t = 2.81, P<0.05].MEG data:1.In recognition memory task, both patient group and control group had a wide range of dorsolateral prefrontal cortex (DLPFC) activation, including right and left Medial Frontal Gyrus(BA9), bilateral pre-motor cortex (BA6), right Broca area (BA44,45), right Middle Frontal Gyrus(BA46), and temporal lobe activation, including right Superior Temporal Gyrus (BA21), right Inferior Temporal Gyrus (BA20), left Medial Temporal Gyrus (BA21) and bilateral superior parietal lobule cortex (BA7,40) ,limbic lobe activation. Control group showed additional activation in cerebellum and right Medial Prefrontal Gyrus (BA4), the difference was significant (P<0.05). Patient group showed additional activation in eye movement area of left frontal lobe (BA8), left Medial Temporal Gyrus (BA21), bilateral thalamus, right Superior Temporal Gyrus (BA21), right Inferior Temporal Gyrus, right hippocampus (BA20), left hippocampus (BA20), the difference was significant (P<0.05). SAM value of inter-group comparison, patients group were generally lower in the same activation areas in frontal lobe of both groups than the control group, the difference was significant (P<0.05). Patient group had unusual increased activation of temporal lobe and hippocampus, the difference was significant (P<0.05).2.In external source memory task , both patient group and control group had a wide range activation in bilateral Medial Frontal Gyrus(BA9,10), ventri and dorso prefrontal lobe cortex (BA46,45,44), bilateral pre-motor and assisted movement cortex (BA6,8), left superior parietal lobule (BA7,40), right precuneus(BA31), anterior cingulate gyrus, posterior cingutate gyrus (BA32,33), left hippocampus (BA20), right hippocampus (BA20), left Superior Temporal Gyrus (BA22), left Medial Temporal Gyrus (BA21), right Superior Temporal Gyrus (BA39), and right Medial Temporal Gyrus (BA21). Control group showed additional activation in bilateral cerebellum, the difference was significant (P<0.05). Patient group showed additional activation in bilateral thalamus, left insular lobe (BA13), right anterior parahippocampal gyrus, left precental gyrus(BA7,19) and left lingual gyrus (BA18), the difference was significant (P<0.05). SAM value of inter-group comparison, the control group were generally higher in prefrontal cortex than patient group, the difference was significant (P<0.05). Patient group had unusual increased activation of temporal lobe margin again, the difference was significant (P<0.05).Conclusion: Both the ability of recognition memory and external source monitoring of male patients with schizophrenia are damaged. The lower activation of a wide range of prefrontal lobe, especially left prefrontal lobe cortex in patients and unusual increased activation of temporal lobe and hippocampus have a close relationship with the impairment of external source monitoring, which surggests that it is the neural mechanisms of external source monitoring. |
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