Analysis of influencing factors of visual working memory in young adult patients with schizophrenia

Background Patients with schizophrenia have general cognitive impairments, and the impairment of working memory is considered to be the basis of cognitive impairments. The research on visual working memory, one of the subcomponents, is getting more and more attention.However, the influencing factors which cause the deficits of visual working memory in patients with schizophrenia have not been clearly explained. To provide evidence for cognitive impairment interventions, the present study explored the factors influencing the deficits of patients' visual working memory.Aim The present study discussed the relevant factors influencing the visual working memory of patients with schizophrenia by measuring the accuracy of the visual working memory of patients with schizophrenia and healthy controls.Methods Colour-recall paradigm was employed to measure the accuracy of the visual working memory of 61 healthy controls and 61 patients who met the International Classification of Diseases, Tenth Revision diagnostic criteria for schizophrenia. The age range of subjects was18-50. Scale for the Assessment of Positive Symptoms(SAPS) and Scale for the Assessment of Negative Symptoms(SANS) were used to evaluate the patients' clinical symptoms.Results Compared with the healthy control group, the accuracy of visual working memory of patients with schizophrenia was significantly impaired(t=3.062,p=0.003). The accuracy of visual working memory of patients with schizophrenia was not related to age(r=0.023,p=0.860),the age of onset(r=-0.003,p=0.979),the duration of illness(r=-0.038, p=0.769),education level(r=-0.181, p=0.162),continuous working time before illness(r =-0.107, p=0.413) or the daily dose of antipsychotic drugs(r =0.062, p=0.635); however, it was positively related to the number of hospitalisations(r =0.471,p<0.001). The total score of Scale for the Assessment of Positive Symptoms(SAPS) was negatively related to the accuracy of visual working memory(r=-0.388, p=0.005), while the total score of Scale for the Assessment of Negative Symptoms(SANS)(r=0.416,p=0.001), the total score of diminished emotional expressiveness(r =0.352, p=0.005) and the total score of attention disorder(r =0.310, p=0.015) were positively related to the accuracy of visual working memory. Patients using a single drug and those using multiple drugs were compared with each other. They were not significantly different in age(t=0.010, p=0.992), the number of hospitalisations(t=0.656, p=0.514), the duration of illness(t=0.701, p=0.486), the total score of SANS(t=0.078,p=0.938), the total score of SAPS(t=1.815, p=0.079) and the daily dose of antipsychotic drugs(t=1.794, p=0.078).However, in order to explore whether single or combined drug use would affect the accuracy of visual working memory of patients with schizophrenia, the present study also compared these two groups' different SO values of the accuracy of visual working memory. The results showed that the accuracy of visual working memory of patients with schizophrenia with combined drug use was significantly better than that of patients with single drug use(t=2.515, p=0.015, independent sample t-test).Conclusion The present study indicates that the visual working memory of young adult patients with schizophrenia is impaired compared with the healthy people within the same age range. The impairment is more obvious in patients who have multiple hospitalisations and suffer from severe negative symptoms. The impairment in patients with more severe positive symptoms is not very obvious. Combined drug use is likely to alleviate the impairment.

The Mystery 40 Hz:Unraveling the Efficacy of Rhythmic Stimulation in Alzheimer's Disease

Promises and Challenges of Rhythmic Stimulation.Recent advances in research have made significant strides in understanding the potential of 40 Hz rhythmic optogenetic stimulation for the treatment of Alzheimer's disease(AD).A pivotal study conducted by Iaccarino et al.(2016)unveiled that targeted stimulation of interneurons at this specific frequency results in a remarkable reduction ofβ-amyloid levels in a mouse model of AD[1].

Prefrontal cortex and sensory cortices during working memory: quantity and quality

The activity in sensory cortices and the prefrontal cortex （PFC） throughout the delay interval of working memory （WM） tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in sensory cortices is fine-tuned to sensory information and forms the neural basis of the precision of WM storage, while the delay activity in the PFC appears to represent behavioral goals and filters out irrelevant distractions, forming the neural basis of the quantity of task-relevant information in WM. The PFC and sensory cortices interact through different frequency bands of neuronal oscillation （theta, alpha, and gamma） to fulfill goal-directed behaviors.

“Transient”or“Persistent”Coding for Working Memory

Working memory(WM)maintains information temporarily for subsequent goal-directed behaviors,such as remembering a telephone number to dial.WM serves as a supporting mental workspace for many cognitive functions such as mental calculation,reading,and learning new skills.The critical role of persistent activity in the prefrontal cortex in WM,originally proposed to bridge sensory information and motor responses[1],has been severely debated recently[2,3].