An extract of Hibiscus sabdariffa improves short-term memory in rats with experimental diabetic hyperglycemia.

BACKGROUND: Calyxes of Hibiscus sabdariffa (Hs) contain anthocyanins, that normalize blood glucose levels (BGL) in diabetic patients. Diabetes also causes memory alterations, which could hypothetically decrease with the consumption of Hs. OBJECTIVES: To investigate the effect of dietary supplementation with a Hs extract on working memory and BGL in rats. METHODS: Diabetic hyperglycemia (DHG) was induced with streptozotocin (STZ, 55 mg/kg i.p.) in Wistar rats. After 72 h DHG was confirmed, and the consumption of Hs extract began (50 mg/Kg/day). BGL and body weight (BW) were measured at 10, 20 and 30 days after DHG induction in controls and treated animals. Learning and short-term memory were evaluated after 30 days with Novel Object Recognition Test (NOR) and Barnes Maze (BM). The gross hippocampal structure was histologically analyzed. RESULTS: STZ-treated animals presented low BW and persistent DHG (BGL <300 mg/dL). Diabetic animals consuming the Hs extract had a dual response: some showed BGL comparable to controls, while others had levels comparable to diabetic animals not consuming extract. Diabetic animals that consumed the Hs extract had a better performance in NOR and BM than the diabetic animals not consuming the extract. At the histological level, hippocampal morphological differences were observed between diabetic animals that consumed the extract and those that did not. DISCUSSION: The Hs extract used here could be a good co-adjuvant in the treatment of DHG, aimed at mitigating memory deficits and high BGL. These beneficial effects could be attributed to the anthocyanin content in the extract.

Mechanisms of Cognitive Change: Training Improves the Quality But Not the Quantity of Visual Working Memory Representations.

As of yet, visual working memory (WM) training has failed to yield consistent cognitive benefits to performance in untrained tasks, despite large improvements in trained tasks. Investigating the mechanisms underlying training effects can help explain these inconsistencies. In this pre-registered, pre-test/post-test online training study, we examined how training affects the quantity and quality of representations in visual WM using continuous-reproduction tasks. N = 64 young healthy adults were randomly assigned to an experimental group or an active control group to complete four training sessions of practce in an orientation-reproduction or a visual search task, respectively. We observed that, in the trained task, only the quality, but not the quantity, of visual WM representations significantly increased in the experimental group relative to the control group. These improvements did not generalise to untrained stimuli or paradigms. Therefore, our findings suggest that training gains are not driven by enhanced capacity. Instead, gains in the quality of visual WM representations that are tied to specific stimuli and paradigms may reflect enhanced efficiency in using the existing visual WM capacity.

Effects of group mindfulness yoga training on sleep quality in college students / 四川精神卫生

ObjectiveTo explore the effectiveness of mindfulness yoga training on sleep quality in college students， so as to provide references for the intervention of sleep problems in college students. MethodsFrom March 28， 2021 to April 20， 2021， A sample of 45 college students with Pittsburgh Sleep Quality Index （PSQI） score ≥8 was recruited. Participants were randomly divided into study group （n=22） and control group （n=23）. Participants in the intervention group received mindfulness yoga training twice a week for 4 weeks. The control group did not receive mindfulness yoga training during the trial， but the same training would be given after the trial. Before and after the intervention， PSQI and the N-back training tasks were used to evaluate the sleep quality and working memory ability of the two groups. ResultsThe main effects of time on the PSQI total score， the accuracy and reaction time of N-back training task were statistically significant （F=37.240， 6.898， 10.775， P<0.05 or 0.01）. The main effects of grouping factors on PSQI total score and the accuracy of N-back training task were statistically significant （F=8.057， 11.093， P<0.05 or 0.01）. The interaction of time and group had statistical significance on PSQI total score and the response time of the N-back training task（F=32.730， 17.578， P<0.01）. After intervention， the PSQI total score of the study group was lower than that before intervention （F=69.898， P<0.01）， and the response time of N-back training task was shorter than that before intervention （F=27.939， P<0.01）， the differences were statistically significant. ConclusionGroup mindfulness yoga training may help improve the sleep quality of college students.

Assessment of neuropsychological impairments in regular cannabis users.

BACKGROUND: Cannabis is the most widely used illicit drug in the world. It is responsible for cognitive dysfunction of memory, speed of information processing, attention, and executive functions. Cognitive performance depends on the level of study, tolerance, and duration of abstinence from cannabis use. This study analyses cognitive function in a large population of regular cannabis consumers taking into account level of education. METHODS: A battery of neuropsychological tests using the Cambridge Neuropsychological Test Automated Battery was performed on a population of 58 cannabis users categorized into two groups according to their level of education with a threshold of 12 years of study, and 25 non-users. RESULTS: In Attention Switching Task percent correct trials, significant differences were found between the group of cannabis smokers with less than 12 years of study and the non-smoker group (P=0.022), and between the cannabis users with more than 12 years of study and the non-smoker group (P=0.008). A significantly lower performance in the Rapid Visual Information Processing (Mean latency, Probability of hit, Total hits, Total misses, Correct rejections) was found in the cannabis users with less than 12 years of study compared with the non-user group. CONCLUSION: In our population, chronic cannabis users presented divided and sustained attention and working memory disorders. Rapid Visual Information Processing performance may be influenced by education level in cannabis smokers.

Influencia del nacimiento prematuro en el desarrollo de funciones ejecutivas de niños en edad escolar / Influence of premature birth in the development of executive functions in children at a school age / Influência do nascimento prematuro no desenvolvimento das funções executivas das crianças em idade escolar

El desarrollo de las funciones ejecutivas culmina con la mielinización cerebral, tal desarrollo va a depender de la estructuración cerebral al momento del nacimiento, en este aspecto se tomó en cuenta la edad gestacional del infante en el momento del parto; a fin de identificar su influencia en el desarrollo de estas funciones se realizó un estudio con un enfoque cuantitativo de diseño descriptivo-correlacional, con una selección de muestra por modelo no probabilístico y voluntario de 160 niños entre 6 y 10 años de edad, divididos en dos grupos, uno clínico, que cumplía los criterios de prematurez expuestos por la OMS, y el otro corresponde a los respectivos pares de la muestra clínica. En los resultados se encontró que los prematuros presentan debilidad en los niveles básicos y complejos del proceso atencional y menos flexibilidad mental, sin presentar mayor compromiso en las estrategias de automonitoreo de la conducta. Al igual que un menor desempeño en relación al desarrollo ejecutivo o de capacidades relacionadas con la organización y planeación.

The development of executive functions ends up with brain mielinization, such development depends on the structure of the brain at the time of birth, this aspect takes into account the length of the pregnancy at the time of birth, in order to identify its influence in the development of these functions, we carried out a study using a quantitative approach with a descriptive-correlation design, with a sample selected using a voluntary non-probabilistic model with a 160 students between the ages of 6 and 10, divided in two groups: a clinical group under the criteria for premature birth established by the WHO and the other group was made up of peers. The results showed that premature children presented weaknesses in basic and complex attention processes and less mental flexibility without compromising self-monitoring behavior strategies. Likewise, there was a lower performance regarding the executive development in capacities related to organization and planification.

O desenvolvimento das funções executivas culmina com a mielinización cerebral, tal desenvolvimento vai depender da estruturação cerebral ao momento do nascimento, neste aspecto, foi tomada em consideração a idade gestacional do infante no momento do parto; a fim de identificar a sua influência no desenvolvimento dessas funções foi realizado um estudo com uma abordagem quantitativa de design descritivo-de correlação, com uma seleção de amostra por modelo não probabilístico e voluntário de 160 crianças entre os 6 e10 anos de idade, divididos em dois grupos, um clínico, que cumpre os critérios de prematuridade expostos pela OMS, e o outro no clinico que corresponde aos respectivos pares da amostra clínica. Nos resultados, descobriuse que as crianças prematuras apresentam fraqueza nos níveis básicos e complexos do processo atenção e menos flexibilidade mental, sem apresentar maior empenho nas estratégias de automonitoramento da conduta. Tal como um menor desempenho em relação ao desenvolvimento executivo de capacidades relacionadas com a organização e planeamento.

Behavior and memory evaluation of Wistar rats exposed to 1·8 GHz radiofrequency electromagnetic radiation.

BACKGROUND: The development of communication systems has brought great social and economic benefits to society. As mobile phone use has become widespread, concerns have emerged regarding the potential adverse effects of radiofrequency electromagnetic radiation (RF-EMR) used by these devices. OBJECTIVE: To verify potential effects of mobile phone radiation on the central nervous system (CNS) in an animal model. METHODS: Male Wistar rats (60 days old) were exposed to RF-EMR from a Global System for Mobile (GSM) cell phone (1·8 GHz) for 3 days. At the end of the exposure, the following behavioral tests were performed: open field and object recognition. RESULTS: Our results showed that exposed animals did not present anxiety patterns or working memory impairment, but stress behavior actions were observed. CONCLUSION: Given the results of the present study, we speculate that RF-EMR does not promote CNS impairment, but suggest that it may lead to stressful behavioral patterns.

Efecto de la medicación en los patrones de activación cerebral en resonancia magnética funcional, ante un paradigma de memoria de trabajo en pacientes con trastorno bipolar tipo I / Effects of Medication on fMRI Brain Activation Patterns in Bipolar Disorder Type I Patients Challenged with Working Memory Tasks

Introducción: Diversos estudios demuestran un aumento en la activación de áreas límbicas y paralímbicas y disminución de la activación en áreas relacionadas con la memoria de trabajo en pacientes con trastorno bipolar. La mayoría de estos estudios se realizan en pacientes que reciben tratamiento farmacológico, lo cual dificulta interpretar hasta qué punto el tratamiento es responsable de las alteraciones encontradas. Objetivo: Identificar las posibles diferencias en la respuesta neurofuncional de pacientes con trastorno bipolar en tareas de memoria operativa y establecer el papel de la medicación en estas diferencias. Metodología: Estudio descriptivo-correlacional de corte transversal. Se evaluaron 43 individuos, de los cuales 33 fueron pacientes eutímicos con trastorno bipolar tipo I (13 en tratamiento con carbonato de litio, 9 con ácido valpróico y 10 sin medicación al menos durante dos meses previos a la evaluación) y 11 controles. La resonancia magnética funcional (RMf) se usó para correlacionar sus procesos de memoria operativa con los cambios vistos en la señal BOLD, usando un paradigma que combina la presentación de bloques y eventos relacionados. Resultados: No se encontraron diferencias significativas en las variables clínicas o demográficas entre los grupos, excepto en el puntaje de la Young Mania Rating Scale (YMRS). Se encontraron diferencias en el patrón de activación del cíngulo anterior al comparar los pacientes bipolares y los controles (p=0,05). Conclusión: Se encontraron diferencias en el patrón de activación del cíngulo anterior en la RMf en una prueba de memoria de trabajo comparando los pacientes bipolares tipo I y los controles.

Background: Patients with bipolar disorder show increased activation in limbic and para-limbic areas whereas they show decreased activity in working memory-related areas. The degree to which pharmacological treatment determines these alterations is hard to gage, given that most studies have been done on patients already receiving such treatments. Objective: We seek to identify differences and the role of treatment in neurofunctional response in patients with bipolar disorder type I compared to controls, specifically while challenged with working memory tasks. Methods: Thirtythree euthymic patients with type I bipolar disorder and 10 controls were evaluated in a cross-sectional study; 13 of them were being treated with lithium, 9 with valproic acid, and 10 had not received treatment for at least 2 months prior to the study. Correlation was established between functional Magnetic Resonance (fMRI) BOLD signal and working memory processes. Results: There were no significant differences between the groups in demographics or clinical variables except for YMRS score. Patients and controls showed significantly different patterns of brain activation in the anterior cingulate (p:0.05) during working memory tasks. Conclusion: There are statistically significant differences in the anterior cingulate BOLD (Blood oxygen level dependent) signal of patients with Type I Bipolar disorder compared to controls.

Application of EEG Non-linear Analysis in Vision Memory Study / 中国康复理论与实践

@#ObjectiveTo investigate the changes of non-linear dynamics characteristics of EEG during picture memory masks, and the application of non-linear dynamic analysis for memory research.MethodsEEGs of 30 healthy old volunteers were recorded under the states of opened eyes and picture memory. Correlation dimension (D2) was calculated for all subjects.ResultsD2 increased significantly during memory tasks compared with the rest state with eyes opened (P<0.05). In different memory tasks, the complexity of mental functions and the regions involved in the memory task were different.ConclusionNon-linear analysis is appropriate for the study of functional changes and working mechanism of brain during memory.