Elastic and inelastic collision dynamics between soliton molecules and a single soliton.

Dissipative systems form various self-organized states owing to the abundant attractor structures. The study of the response of different self-organized states under collision perturbation is of great significance for understanding the dissipative nonlinear systems. The collision dynamics of single soliton and soliton molecules can not only assist the stability analysis of attractors, but also reveal the rich physical connotations of soliton interactions. Here, for the first time, the collision processes of single soliton and soliton molecules in different excited states are detected using the dispersive Fourier transform technology. The collision processes include the disintegration and rebuilding of soliton molecules as well as chaotic oscillating evolution, accompanied by the emergence of transition states such as triple binding state, soliton fusion and acceleration. According to whether the soliton molecule can return to its initial excited state, the collisions are classified as elastic and inelastic. The different interaction strength between solitons is an important condition for rebuilding stable soliton molecules. Numerical simulations show that the gain dynamics are the main physical origin of collisions. Our research will stimulate in-depth research on the interaction of self-organized states in nonlinear systems such as chemical molecules, and have potential applications in optical logic gates.

Immersive Virtual Reality-Based Cognitive Intervention for the Improvement of Cognitive Function, Depression, and Perceived Stress in Older Adults With Mild Cognitive Impairment and Mild Dementia: Pilot Pre-Post Study.

BACKGROUND: The incidence of dementia is increasing annually, resulting in varying degrees of adverse effects for individuals, families, and society. With the continuous development of computer information technology, cognitive interventions are constantly evolving. The use of immersive virtual reality (IVR) as a cognitive intervention for older adults with mild cognitive impairment (MCI) and mild dementia (MD) is promising, although only few studies have focused on its use. OBJECTIVE: The Chinese virtual supermarket (CVSM) IVR system was developed to provide a comprehensive and individual cognitive intervention program for older patients with MCI and MD. The aim of this study was to explore the feasibility and clinical effectiveness of this 5-week IVR-based cognitive intervention. METHODS: A pretest-posttest study design was conducted with 31 older adults with MCI and MD from August 2020 to January 2021. All participants participated in a 5-week immersive virtual cognitive training program using the CVSM system. Feasibility was assessed as the incidence and severity of cybersickness symptoms and participant satisfaction based on questionnaires conducted after the intervention. Clinical effectiveness was evaluated using neuropsychological assessments, including several commonly used measures of cognitive function, depression, perceived stress, and activities of daily living. Measurements were obtained at baseline and after the intervention period. RESULTS: A total of 18 patients with MCI (mean age 82.94 [SD 5.44] years; 12 females) and 13 patients with MD (mean age 85.7 [SD 4.67] years, 10 females) participated in this pilot study. Both groups showed significant improvements in all cognitive function measurements (P<.001). The MD group had a significantly greater improvement in general cognitive function compared to the MCI group in Montreal Cognitive Assessment Scale, Symbol Digit Modalities Test, Shape Trail Test, and Auditory Verbal Learning Test. Furthermore, an intervention effect was observed in the improvement of perceived stress (P=.048 for MD group, P=.03 for MCI group ). CONCLUSIONS: The use of the CVSM system may be effective in enhancing the cognitive function of patients with MCI and MD, including general cognitive function, memory, executive function, and attention. IVR technology enriches cognitive intervention approaches and provides acceptable, professional, personalized, and interesting cognitive training for older adults with cognitive impairment. TRIAL REGISTRATION: ClinicalTrials ChiCTR2100043753; https://trialsearch.who.int/Trial2.aspx?TrialID=ChiCTR2100043753.

Study of virtual reality for mild cognitive impairment: A bibliometric analysis using CiteSpace.

OBJECTIVES: Non-invasive and low-cost virtual reality (VR) technology is important for early evaluation and intervention in mild cognitive impairment (MCI). This study aimed to demonstrate the current status of overseas and domestic research as well as the focus and frontier of VR technology among individuals with MCI through a bibliometric analysis. METHODS: Studies from the core collection of Web of Science™ between 1995 and 2020 were used; furthermore, CiteSpace 5.7 R3 was utilized to analyse information on authors/cited authors, keywords, burst words, and cited references. RESULTS: In total, 230 publications were identified. Most studies were published in the USA (45 publications) and Italy (41 publications), where Guiseppe Riva ranks first (14 publications), and Tarnanas I is the author with the highest centrality (0.44). The hot topics in VR applications in the MCI population are 'physical activity,' 'people,' 'single-blind,' 'disease,' 'walking,' 'technology,' 'working memory,' and 'risk' in recent years. The keyword 'mild cognitive impairment' has attracted extensive attention since 2012, showing the strongest citation outbreak (8.28). The clustering results of the literature show the research types and emerging trends, including 'exergame,' 'serious games,' 'spatial navigation,' 'activities of daily living,' 'exercise,' 'enriched environment' and 'wayfinding.' CONCLUSIONS: Cognitive assessment and nonpharmacological intervention research on patients with MCI have become the focus of dementia prevention in recent years. Virtual technology, combined with traditional methods such as exercise therapy, provides new ideas for innovative cognitive evaluation and cognitive intervention.

Oscillatory self-organization dynamics between soliton molecules induced by gain fluctuation.

In passively mode-locked fiber lasers (PMLFLs), the dissipative solitons (DSs) can self-organize to form complex structures through delicate interactions. However, it is still elusive to control these soliton structures by external influences. We here find that at a certain critical power, the location between two soliton molecules can be controlled by a slow modulated pump power. After applying the pump power with periodic fluctuation, two soliton molecules oscillate from the state of soliton molecular complex to stable distribution with maximum inter-molecular separation. During this process, the internal structure of each soliton molecule keeps steady. The slow gain depletion and recovery mechanism which plays a dominant role affects the motion of soliton molecules. These results could further expand the molecular analogy of spectroscopy and stimulate the development of optical information storage and processing.

Effects of expressive arts therapy in older adults with mild cognitive impairment: A pilot study.

Expressive arts therapy (EAT) can potentially improve cognition and mental health in patients with dementia. However, limited studies have been conducted for older adults with mild cognitive impairment (MCI). The aim of this study was to examine the effects of EAT in older adults with MCI. A total of 48 participants with MCI were assigned to the EAT intervention (n = 24) or waiting list control (n = 24) group. The former received 60-90 min of EAT twice a week for 6 weeks. The findings showed that the EAT program had a high retention and attendance rate and a high level of general satisfaction. Moreover, the intervention group showed significant improvements in general cognitive function, language function, anxiety, depression, and the psychological and social relationship domains of quality of life. The results provide preliminary evidence for the feasibility and efficacy of EAT intervention in older adults with MCI.

Effects of Creative Expressive Arts-based Storytelling (CrEAS) programme on older adults with mild cognitive impairment: protocol for a randomised, controlled three-arm trial.

INTRODUCTION: Early non-pharmacological interventions can prevent cognitive decline in older adults with mild cognitive impairment (MCI). Creative expression (CrExp) can potentially mitigate cognitive decline and enhance the physical and mental health of older people. However, it is unclear whether activities involving CrExp can improve cognitive function and other health-related outcomes in older adults with MCI. The aim of the present study is to develop a Creative Expressive Arts-based Storytelling (CrEAS) programme that integrates verbal and non-verbal expressive activities and evaluate its effectiveness in improving cognitive function and other outcome indicators so as to explore its possible mechanism from the perspective of neuroimaging. METHODS AND ANALYSIS: This parallel randomised controlled trial with three arms (one intervention and two control arms) will be conducted over a 24-week period. A total of 111 participants will be enrolled and randomised to the CrEAS, recreation and usual activity groups. The CrEAS programme combines visual arts therapy and storytelling (TimeSlips) under the Expressive Therapy Continuum theoretical framework and provides an opportunity for people with MCI to actively engage in activities to improve cognitive function through verbal and nonverbal CrExp. Global cognitive function, specific domains of cognition (memory, executive function, language and attention) and other health-related outcomes (anxiety, depression and quality of life) will be measured at baseline, at the end of the intervention, and at the 24-week follow-up. Structural/functional brain MRI data will be collected at baseline and immediately after the intervention. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ethics Committee of Fujian Provincial Hospital (K2018-03-061). The study results will be disseminated through peer-reviewed journals and at academic conferences. TRIAL REGISTRATION NUMBER: ChiCTR1900021526.