Generalization of Context-Specific Training in Individuals with Mild Cognitive Impairment: An Event-Related Potential Study

Enhanced Medial Prefrontal Cortex and Hippocampal Activity Improves Memory Generalization in APP/PS1 Mice: A Multimodal Animal MRI Study

Memory generalization allows individuals to extend previously learned movement patterns to similar environments, contributing to cognitive flexibility. In Alzheimer’s disease (AD), the disturbance of generalization is responsible for the deficits of episodic memory, causing patients with AD to forget or misplace things, even lose track of the way home. Cognitive training can effectively improve the cognition of patients with AD through changing thinking mode and memory flexibility. In this study, a T-shaped maze was utilized to simulate cognitive training in APP/PS1 mice to elucidate the potential mechanisms of beneficial effects after cognitive training. We found that cognitive training conducted by a T-shaped maze for 4 weeks can improve the memory generalization ability of APP/PS1 mice. The results of functional magnetic resonance imaging (fMRI) showed that the functional activity of the medial prefrontal cortex (mPFC) and hippocampus was enhanced after cognitive training, and the results of magnetic resonance spectroscopy (MRS) showed that the neurochemical metabolism of N-acetyl aspartate (NAA) and glutamic acid (Glu) in mPFC, hippocampus and reuniens (Re) thalamic nucleus were escalated. Furthermore, the functional activity of mPFC and hippocampus was negatively correlated with the escape latency in memory generalization test. Therefore, these results suggested that cognitive training might improve memory generalization through enhancing the functional activity of mPFC and hippocampus and increasing the metabolism of NAA and Glu in the brain regions of mPFC, hippocampus and Re nucleus.

Arts-based interventions to improve cognition in older persons with mild cognitive impairment: A systematic review of randomized controlled trials

OBJECTIVES

As the global burden of dementia rises, the search for preventive measures such as interventions for mild cognitive impairment (MCI) remains a research priority. While arts-based interventions have demonstrated some success in improving cognitive functioning among older adults and those with dementia, its effectiveness for older persons with MCI remains unexplored. We conducted a systematic review to examine the effects of arts-based interventions on cognition in older persons with MCI.

METHOD

The following databases were searched in November 2019: PubMed, EMBASE, PsycINFO, and CINAHL Plus, supplemented by Google Scholar and ALOIS. Study inclusion criteria were older persons aged ≥ 60 with MCI; arts-based interventions such as dance, drama, music, or visual arts; and randomized controlled trial with cognitive outcome. Database search, study selection, and data extraction were conducted independently by 2 reviewers.

RESULTS

Eleven randomized controlled trials examining 13 interventions (817 participants) were identified, of which 4 involved visual arts, 4 dance/movement, 3 music, and 2 storytelling. Significant improvement on at least one cognitive outcome was reported in 10 of the 13 interventions. These included improvements in global cognition (6/7 interventions), learning and memory (5/9), complex attention (4/10), executive functioning (2/6), language (2/3), and perceptual-motor function (1/4).

CONCLUSION

This review found that arts-based interventions can potentially improve various aspects of cognitive functioning in older persons with MCI, although our confidence was dampened by methodological limitations such as the moderate-to-high risk of bias present in studies and heterogeneity in the way MCI was defined. Recommendations for future research are discussed.

Outcomes tested in non-pharmacological interventions in mild cognitive impairment and mild dementia: a scoping review

OBJECTIVES

Non-pharmacological treatments are an important aspect of dementia care. A wide range of interventions have been trialled for mild dementia and mild cognitive impairment (MCI). However, the variety of outcome measures used in these trials makes it difficult to make meaningful comparisons. The objective of this study is to map trends in which outcome measures are used in trials of non-pharmacological treatments in MCI and mild dementia.

DESIGN

Scoping review.

DATA SOURCES

EMBASE, PsychINFO, Medline and the Cochrane Register of Controlled Trials were searched from inception until February 2018. An additional search was conducted in April 2019 ELIGIBILITY: We included randomised controlled trials (RCTs) testing non-pharmacological interventions for people diagnosed with MCI or mild dementia. Studies were restricted to full RCTs; observational, feasibility and pilot studies were not included.

CHARTING METHODS

All outcome measures used by included studies were extracted and grouped thematically. Trends in the types of outcome measures used were explored by type of intervention, country and year of publication.

RESULTS

91 studies were included in this review. We extracted 358 individual outcome measures, of which 78 (22%) were used more than once. Cognitive measures were the most frequently used, with the Mini-Mental State Examination being the most popular.

CONCLUSIONS

Our findings highlight an inconsistency in the use of outcome measures. Cognition has been prioritised over other domains, despite previous research highlighting the importance of quality of life and caregiver measures. To ensure a robust evidence base, more research is needed to highlight which outcome measures should be used over others.

PROSPERO REGISTRATION NUMBER

CRD42018102649.

Event-related neural oscillation changes following reasoning training in individuals with Mild Cognitive Impairment

Emerging evidence suggests cognitive training programs targeting higher-order reasoning may strengthen not only cognitive, but also neural functions in individuals with Mild Cognitive Impairment (MCI). However, research on direct measures of training-induced neural changes, derivable from electroencephalography (EEG), is limited. The current pilot study examined effects of Gist Reasoning training (n = 16) compared to New Learning training (n = 16) in older adults with amnestic MCI on measures of event-related neural oscillations (theta and alpha band power) corresponding to Go/NoGo tasks during basic and superordinate semantic categorization. EEG data were recorded while participants performed the Go/NoGo task pre- and post-training, and power in theta and alpha frequency bands was examined. Both groups were comparable at pre-training on all measures and both groups showed greater event-related theta synchronization post-training. Furthermore, the Gist Reasoning group had enhanced event-related desynchronization in low-frequency alpha band (8-10 Hz) on response inhibition (NoGo) trials and high-frequency alpha band (11-13 Hz) on response execution (Go) trials during superordinate categorization, relative to the New Learning group. These findings suggest that Gist Reasoning training in MCI impacted neural processing linked to strategic processing of Go and NoGo trials during the more complex superordinate categorization task. Targeting higher-order top-down cognitive processing seems to better harness residual neuroplastic potential in MCI. ClinicalTrials.gov ID: NCT02588209.

Does Chinese calligraphy therapy reduce neuropsychiatric symptoms: a systematic review and meta-analysis

BACKGROUND

There are currently no systematic reviews or meta-analyses of Chinese calligraphy therapy (CCT) to reduce neuropsychiatric symptoms. The aim of this systematic review and meta-analysis was to explore the efficacy of CCT for people with neuropsychiatric symptoms.

METHODS

We searched Chinese and English databases, including the Cochrane Central Register of Controlled Trials and Wanfang Data for relevant articles published between the earliest year available and December 2016. The search was limited to randomized controlled trials and controlled clinical studies and the associated keywords were "handwriting," "Chinese calligraphy," "Chinese calligraphy therapy," "Calligraphy exercise," and "Calligraphy training." The 21 articles that met these criteria were used in the analysis. The Joanna Briggs Institute critical appraisal checklist was used to assess methodological quality.

RESULTS

CCT significantly reduced psychosis (10 studies, 965 subjects, standardized mean difference [SMD] = - 0.17, 95% confidence intervals [CI] [- 0.30, - 0.40], Z = 2.60, p < 0.01), anxiety symptoms (9 studies, 579 subjects, SMD = - 0.78, 95% CI [- 0.95, - 0.61], Z = 8.98, p < 0.001), and depressive symptoms (7 studies, 456 subjects, SMD = - 0.69, 95% CI [- 0.88, - 0.50], Z = 7.11, p < 0.001). CCT also significantly improved cognitive function (2 studies, 55 subjects, MD = 2.17, 95% CI [- 0.03, 4.38], Z = 1.93, p = 0.05) and neurofeedback (3 studies, 148 subjects, SMD = - 1.09, 95% CI [- 1.44, - 0.73], Z = 6.01, p < 0.001). The therapy also significantly reduced the positive psychopathological expression of schizophrenia symptoms (4 studies, 287 subjects, SMD = - 0.35, 95% CI [- 0.59, - 0.12], Z = 2.96, p = 0.003) and reduced the negative symptoms of schizophrenia (4 studies, 276 subjects, SMD = - 1.39, 95% CI [- 1.65, - 1.12], Z = 10.23, p < 0.001).

CONCLUSIONS

CCT exerts a curative effect on neuropsychiatric symptoms, but the evidence remains insufficient. A large number of RCTs are needed to facilitate additional systematic reviews of evidence for CCT.