Study On Memory Monitoring Ability Of Patients With Schizophrenia

Objective Schizophrenia is a kind of common disease, which has not been fully clarified. The global prevalence rate is about 1%, the chronic rate is high, and the disability rate is high, which brings more serious economic burden to the society. Cognitive deficits in patients with schizophrenia has been confirmed by numerous studies, patients have sensation, perception, memory, thinking, language barriers, which impaired memory is particularly evident, scholars put forward memory impairment may be the core damage of cognitive function in patients with schizophrenia. Impaired memory may be caused by insufficient memory monitoring. Memory monitoring is a meta cognitive process, it is the subjective assessment and judgment of encoding, storage, extraction and other memory stage, in order to understand the situation of the object memory. At present, the research of memory monitoring is relatively few, and the research material is mainly based on visual pictures. In patients with schizophrenia as the study object, especially the use of auditory material to investigate the memory monitoring ability of schizophrenia patients is still lack, so this study will use auditory source memory monitoring paradigm and feeling-of-knowing paradigm to examine the schizophrenia patients with memory monitoring ability, and to explore the possible mechanism of memory impairment in patients with.Methods In study one, the source memory monitoring ability of forty-seven patients with schizophrenia who were in stable stage and forty-nine healthy control subjects matched for gender, age, education were tested by the external auditory source memory monitoring task. The clinical symptoms of schizophrenic were assessed by the positive and negative symptom scale(PANSS). In study two, the memory monitoring ability of thirty-eight patients with schizophrenia who were in stable stage and thirty-eight cases of gender, age, education degree matched healthy control subjects were studied, by using episodic memory and semantic memory feeling-of-knowing paradigm.Results In study one, the correct rates of item memory and source memory in patients were lower than those in control group [(0.65±0.09) vs(0.75±0.10);(0.62±0.14) vs(0.71±0.16)], and the difference was statistically significant(mean P < 0.01). The accuracies of total source memory monitoring and old word source memory monitoring of the patients group were lower than those in the control group [(0.45±0.24) vs(0.63±0.23);(0.66±0.23) vs(0.75±0.18)], and the difference was statistically significant(mean P < 0.05). Pearson correlation analysis showed that the accuracies of total source memory monitoring and old word source memory monitoring were negatively correlated with the total score of PANSS[respectively as:(r =-0.429, P < 0.01);(r =-0.439, P < 0.01)] and positive symptom score [respectively as:(r =-0.449, P < 0.01);(r =-0.479, P < 0.01)](mean P < 0.01). In study two, the cue recall rate of FOK-EM [(36.97±24.45)%] and FOK-SM [(72.11±19.78)%] as well as the FOK judgment accuracy of FOK-EM [(61.97±18.56)%] in patient group were both significantly lower than that of the control group [respectively as:(65.79±21.01)%;(80.26±13.25)%;(75.03±22.50)%](all Ps < 0.05). The positive judgment and correct recognition of FOK-EM [(46.24±29.68)%] and the negative judgment and correct recognition(underestimate) of FOK-EM [(20.82±21.56)%] in patient group were significantly different from those in control group [respectively as:(72.92±24.27)%;(9.24±15.85)%](all Ps < 0.05). In addition, the stroop effect was positively correlated with the negative judgment and correct recognition(underestimate) of FOK-EM in patient group(r=0.406, P =0.012).Conclution In study one, the source memory monitoring ability of patients with schizophrenia was impaired, and the source memory monitoring ability was negatively correlated with both the total score of PANSS and positive symptom score. In study two, episodic memory monitoring was impaired in patients with schizophrenia, and the impairment of episodic memory monitoring was associated with the deficit of executive function. At the same time, the semantic memory monitoring of patients was relatively preserved, suggesting that episodic memory monitoring and semantic memory monitoring may depend on different neural mechanisms.