The Role of Physical Fitness in the Neurocognitive Performance of Task Switching in Older Persons with Mild Cognitive Impairment

Cardiorespiratory fitness is associated with cognitive performance in 80 + -year-olds: Detangling processing levels

Cardiorespiratory fitness is known to protect against cognitive decline in older adults. Specifically, it has been shown that physical activity and fitness are beneficial for executive functions that are crucial for independent living up to old age. In this study, 115 individuals aged 80 years and older underwent a cardiorespiratory fitness assessment using the two-minute step test and had their electroencephalogram recorded during a colored flanker task in order to measure executive function performance. Cardiorespiratory fitness was related to quicker responses during the flanker task. A mediation analysis was carried out to determine whether these positive effects were mediated through event-related potentials (N1, N2, or P3) or motor-related cortical potentials (MRCP). Cardiorespiratory fitness was related to better visual discriminative processing as indicated by larger occipital N1 amplitudes. In addition, fitness was associated with larger MRCP amplitudes, which are a correlate of the response generation process. Fitness was not found to have a significant effect on fronto-central N2 or parietal P3, which are thought to capture cognitive control processes such as conflict detection and response inhibition. Moreover, all effects reported were present in all three flanker trial conditions (congruent, neutral, and incongruent). Thus, these results indicate that the quicker response times in fitter people were related to visual processing and motor response generation rather than cognitive control.

The assessment of executive function abilities in healthy and neurodegenerative aging-A selective literature review

Numerous studies have examined executive function (EF) abilities in cognitively healthy older adults and those living with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Currently, there are no standard accepted protocols for testing specific EFs; thus, researchers have used their preferred tool, which leads to variability in assessments of decline in a particular ability across studies. Therefore, there is a need for guidance as to the most sensitive tests for assessing EF decline. A search of the most current literature published between 2000 and 2022 on EF studies assessing cognitively healthy older adults and individuals living with MCI and AD was conducted using PubMed/Medline, PsycINFO, Embase, Web of Science, and Google Scholar. Emphasis was placed on the EF's dual-tasking, inhibition, shifting or switching, and working memory updating. Many tasks and their outcomes were reviewed. Of particular importance was the difference in outcomes for tasks applied to the same group of participants. These various EF assessment tools demonstrate differences in effectively identifying decline in EF ability due to the aging process and neurodegenerative conditions, such as MCI and AD. This review identifies various factors to consider in using particular EF tasks in particular populations, including task demand and stimuli factors, and also when comparing differing results across studies.

Executive function measures of participants with mild cognitive impairment: Systematic review and meta-analysis of event-related potential studies

OBJECTIVE

Objective measurements of executive functions using event-related potential (ERP) may be used as markers for differentiating healthy controls (HC) from patients with mild cognitive impairment (MCI). ERP is non-invasive, cost-effective, and affordable. Older adults with MCI demonstrate deteriorated executive function, serving as a potentially valid neurophysiological marker for identifying MCI. We aimed to review published ERP studies on executive function in older adults with MCI and summarize the performance differences by component between healthy older adults and older adults with MCI.

METHODS

Eight electronic databases (Web of Science, PubMed, ScienceDirect, American Psychological Association PsycNet, Cochrane Library, Scopus, Embase, and Ovid) were searched for the study. Articles published from January 1 to December 31, 2022, were considered for this review. A random-effects meta-analysis and between-study heterogeneity analysis were conducted using Comprehensive Meta-Analysis V3.0 software.

RESULTS

We identified 7829 articles of which 28 met the full inclusion criteria and were included in the systematic review and analyses. Our pooled analysis suggested that participants with MCI can be differentiated from HC by significant P200, P300, and N200 latencies. The P100 and P300 amplitudes were significantly smaller in participants with MCI when compared with those in the HCs, and the patients with MCI showed increased N200 amplitudes. Our findings provide new insights into potential electrophysiological biomarkers for diagnosing MCI.

Monitoring Disease Severity of Mild Cognitive Impairment from Single-Channel EEG Data Using Regression Analysis

A deviation in the soundness of cognitive health is known as mild cognitive impairment (MCI), and it is important to monitor it early to prevent complicated diseases such as dementia, Alzheimer's disease (AD), and Parkinson's disease (PD). Traditionally, MCI severity is monitored with manual scoring using the Montreal Cognitive Assessment (MoCA). In this study, we propose a new MCI severity monitoring algorithm with regression analysis of extracted features of single-channel electro-encephalography (EEG) data by automatically generating severity scores equivalent to MoCA scores. We evaluated both multi-trial and single-trail analysis for the algorithm development. For multi-trial analysis, 590 features were extracted from the prominent event-related potential (ERP) points and corresponding time domain characteristics, and we utilized the lasso regression technique to select the best feature set. The 13 best features were used in the classical regression techniques: multivariate regression (MR), ensemble regression (ER), support vector regression (SVR), and ridge regression (RR). The best results were observed for ER with an RMSE of 1.6 and residual analysis. In single-trial analysis, we extracted a time-frequency plot image from each trial and fed it as an input to the constructed convolutional deep neural network (CNN). This deep CNN model resulted an RMSE of 2.76. To our knowledge, this is the first attempt to generate automated scores for MCI severity equivalent to MoCA from single-channel EEG data with multi-trial and single data.

Effects of exercise interventions on executive function in old adults with mild cognitive impairment: A systematic review and meta-analysis of randomized controlled trials

AIMS

To assess the effect of exercise interventions on subdomains of executive function (EF) in older adults with mild cognitive impairment (MCI).

METHODS

Nine electronic databases were comprehensively searched from their inception to February 2021. Randomized controlled trials examining the effect of exercise training on EF in MCI were included.

RESULTS

Twenty-four eligible articles involving 2278 participants were identified. The results showed that exercise interventions had positive benefits on working memory, switching and inhibition in MCI. Subgroup analysis based on exercise prescriptions revealed that both aerobatic exercise and mind-body exercise had similar positive effect size on working memory. However, only mind-body exercise had significant effect on switching. Exercise training with moderate frequency (3-4 times/week) had larger effect size than low frequency (1-2 times/week) and only moderate frequency had positive benefits on switching. Both short (4-12 weeks), medium (13-24 weeks) and long (more than 24 weeks) exercise duration significantly ameliorate working memory and switching, however with short duration having slight larger effect sizes than medium and long.

CONCLUSION

Exercise significantly improves three subdomains of EF in MCI, especially mind-body exercise. Exercise training sticking to at least 4 weeks with 3-4 times a week tends to have larger effect size.

Sleep EEG-Based Approach to Detect Mild Cognitive Impairment

Mild Cognitive Impairment (MCI) is an early stage of dementia, which may lead to Alzheimer's disease (AD) in older adults. Therefore, early detection of MCI and implementation of treatment and intervention can effectively slow down or even inhibit the progression of the disease, thus minimizing the risk of AD. Currently, we know that published work relies on an analysis of awake EEG recordings. However, recent studies have suggested that changes in the structure of sleep may lead to cognitive decline. In this work, we propose a sleep EEG-based method for MCI detection, extracting specific features of sleep to characterize neuroregulatory deficit emergent with MCI. This study analyzed the EEGs of 40 subjects (20 MCI, 20 HC) with the developed algorithm. We extracted sleep slow waves and spindles features, combined with spectral and complexity features from sleep EEG, and used the SVM classifier and GRU network to identify MCI. In addition, the classification results of different feature sets (including with sleep features from sleep EEG and without sleep features from awake EEG) and different classification methods were evaluated. Finally, the MCI classification accuracy of the GRU network based on features extracted from sleep EEG was the highest, reaching 93.46%. Experimental results show that compared with the awake EEG, sleep EEG can provide more useful information to distinguish between MCI and HC. This method can not only improve the classification performance but also facilitate the early intervention of AD.

The Effects of a Magic Intervention Program on Cognitive Function and Neurocognitive Performance in Elderly Individuals With Mild Cognitive Impairment

Objectives

Cognitive training is one of the management options for elderly individuals who suffer from mild cognitive impairment (MCI) and an effective way to improve executive function. This study aimed to evaluate the effectiveness of a magic intervention program as a method of cognitive training in improving cognitive function and neurocognitive performance in this group.

Methods

Twenty-four participants aged 60-80 years with MCI were recruited and randomly assigned to a magic intervention group or a control group. The magic intervention group received a 6-week magic intervention program. The primary endpoints were the scores for the cognitive assessment tests [e.g., Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA)] for general cognitive function. The secondary endpoints were the behavioral [e.g., accuracy and reaction times] and the electroencephalographic [e.g., event-related potential (ERP) P3 amplitudes] performance during the Flanker task to assess attention and inhibitory control. All variables were measured before and after the magic intervention.

Results

The results showed that the 6-week magic intervention significantly improved the MoCA scores in the cognitive assessment tests although no significant pre-post intervention difference was observed in the MMSE scores. In terms of neurocognitive performance, the magic intervention had significantly positive effects on the accuracy, reaction times, and P3 amplitudes when performing the Flanker task.

Conclusion

The results of the present study showed that the 6-week magic intervention had beneficial effects on the cognitive and electrophysiological performance in the elderly subjects with MCI. For such a group, lifestyle intervention programs that encourage participation such as the magic practice and performance may be a viable suggestion to prevent the progression of MCI to Alzheimer's disease.

Acute Effects of Different Exercise Intensities on Executive Function and Oculomotor Performance in Middle-Aged and Older Adults: Moderate-Intensity Continuous Exercise vs. High-Intensity Interval Exercise

A wealth of evidence has shown that a single bout of aerobic exercise can facilitate executive function. However, none of current studies on this topic have addressed whether the magnitude of the acute-exercise benefit on executive function and oculomotor performance is influenced by different aerobic exercise modes. The present study was thus aimed toward an investigation of the acute effects of high-intensity interval exercise (HIIE) vs. moderate-intensity continuous exercise (MICE) on executive-related oculomotor performance in healthy late middle-aged and older adults. Using a within-subject design, twenty-two participants completed a single bout of 30 min of HIIE, MICE, or a non-exercise-intervention (REST) session in a counterbalanced order. The behavioral [e.g., reaction times (RTs), coefficient of variation (CV) of the RT], and oculomotor (e.g., saccade amplitude, saccade latency, and saccadic peak velocity) indices were measured when participants performed antisaccade and prosaccade tasks prior to and after an intervention mode. The results showed that a 30-min single-bout of HIIE and MICE interventions shortened the RTs in the antisaccade task, with the null effect on the CV of the RT in the late middle-aged and older adults. In terms of oculomotor metrics, although the two exercise modes could not modify the performance in terms of saccade amplitudes and saccade latencies, the participants’ saccadic peak velocities while performing the oculomotor paradigm were significantly altered only following an acute HIIE intervention. The present findings suggested that a 30-min single-bout of HIIE and MICE interventions modulated post-exercise antisaccade control on behavioral performance (e.g., RTs). Nevertheless, the HIIE relative MICE mode appears to be a more effective aerobic exercise in terms of oculomotor control (e.g., saccadic peak velocities) in late middle-aged and older adults.

The application of a neuropsychological measure of executive working memory in older adults with memory impairment

The component of working memory that the frontal cortex subserves is frequently characterized as the executive working memory (EWM). This study applied a neuropsychological measure of EWM (NPM-EWM) in older adults with memory impairment to investigate the EWM. Thirty-two older adults from the community were recruited as older healthy controls (OHCs), and 58 older adults from a memory clinic were diagnosed with mild cognitive impairment (MCI) and mild dementia (MD). Significant differences were found among the three groups in the Clinical Dementia Rating (CDR), the Chinese version of Mini-Mental State Examination (MMSE-C), and the Cognitive Abilities Screening Instrument (CASI). The NPM-EWM was applied by using the learning task of the Comprehensive Nonverbal Memory Test Battery, where the 7 scores were divided into two categories: mnemonic capacity and executive error. All OHCs, more than 50% MCI, and less than 25% of MD patients passed the NPM-EWM. The MCI-passed and MD-passed subgroups showed similar mnemonic capacity and executive errors, and both the subgroups had significantly worse performance than the OHC group. The MD-passed subgroup had a higher Hamilton Depression Rating Scale (HDRS) score than did the MD-failed subgroup. The MCI-failed subgroup had a higher Hierarchy of Care Required (HCR) level in instrumental activities of daily living (IADL) than did the MCI-passed subgroup. These findings indicated that applying the NPM-EWM for older adults with memory impairment may offer precise and tailored care to a whole person, especially for the MCI patients with poorer EWM and the MD patients with relatively intact EWM.

A cross-sectional examination of a family history of Alzheimer's disease and ApoE epsilon 4 on physical fitness, molecular biomarkers, and neurocognitive performance

PURPOSE

The present study examined whether the ɛ4 allele of the apolipoprotein E (ApoE) gene impacts molecular biomarkers and neurocognitive performance among individuals at genetic risk for developing Alzheimer's disease (AD). The correlations between physical fitness and molecular/neurocognitive indices were also explored.

METHODS

Fasting blood samples were collected from 162 individuals with a family history of AD (ADFH). There were twenty-two carriers of the ApoE-4 variant (ApoE-4 group). For comparison purposes we randomly selected 22 non-ɛ4 carriers (non-ApoE-4 group) from the ADFH individuals. Circulating inflammatory cytokines (e.g., TNF-α, IL-1β, IL-6, IL-8, and IL-15), neuroprotective growth factors (e.g., BDNF, IGF-1, IGF-2, VEGF, and FGF-2), and Amyloid-β peptides (e.g., Aβ1-40 and Aβ1-42), neurocognitive performance [e.g., behavior and brain even-related potentials (ERP)] during a task-switching paradigm, as well as physical fitness scores were measured.

RESULTS

The ApoE-4 group relative to the non-ApoE-4 group was similar with respect to molecular biomarkers, physical fitness, and most measures of neurocognitive performance. However, ADFH individuals that were ɛ4 carriers exhibited significantly higher local switching accuracy costs, worse accuracy as well as smaller ERP P3 amplitudes for the memory-switching condition. Importantly, cardiorespiratory fitness levels were significantly correlated with accuracy for most task-switching conditions, and levels of BDNF, Aβ1-40, and Aβ1-42 collapsed across the two groups even when controlling for the age co-variable, while the ApoE-4 group revealed similar pattern of results.

CONCLUSIONS

These data suggest that individuals with ADFH that were carriers of the ApoE-4 variant performed worse on the task-switching paradigm and that this could be due to compromised task-set and memory updating processes. Physical exercise interventions aimed to enhance cardiorespiratory fitness levels could be a potential AD prevention strategy for ameliorating cognitive function and reducing the accumulation of the Aβ peptides in this high risk group.

Circulating levels of Irisin in obese individuals at genetic risk for Alzheimer's disease: Correlations with amyloid-β, metabolic, and neurocognitive indices

Irisin is involved in various metabolic pathways and is suggested to be a potential agent capable of preventing onset of Alzheimer's disease (AD) and ameliorating AD neuropathology and cognitive deficits. In the present study, the serum levels of Irisin and Amyloid-β (Aβ) peptides and the neurocognitive performance among obese individuals at genetic risk for AD were investigated. The correlations between Irisin and AD-related neuropathological and neurocognitive indices were also explored. Thirty-two individuals with a family history of AD (ADFH) and obesity (ADFH-obesity group) and 32 controls (ADFH-non-obesity group) were recruited. Circulating levels of Irisin, Aβ peptides, and metabolic biomarkers, as well as neurocognitive performance [e.g., behavior and brain even-related potentials (ERP)] were measured during a visuospatial working memory task. Although the ADFH-obesity group exhibited comparable reaction times, ERP N2 latency and amplitudes, and P3 latency as compared to the ADFH-non-obesity group when performing the cognitive task, they exhibited significantly lower rates of accuracy and smaller P3 amplitudes in the higher memory-load condition, even when controlling for the blood pressure and cardiorespiratory fitness co-variables. The serum levels of leptin, insulin, and glucose, and HOMA-IR were significantly higher in the ADFH-obesity group relative to the ADFH-non-obesity group, but this was not the case for the levels of Aβ1-40 and Aβ1-42. The Irisin levels approached between-group significance. Partial correlations adjusting for cardiorespiratory fitness and blood pressure showed that Irisin levels were positively associated with neurophysiological (i.e., P3 amplitude) performance in the ADFH-obesity group. The Irisin levels were not significantly correlated with the levels of Aβ1-40 and Aβ1-42. The present findings suggest that ADFH individuals with obesity exhibited neurocognitive deficits when performing the visuospatial working memory task, and serum Irisin levels could be one of the influencing factors. However, the relationship between the circulating levels of Irisin and Aβ peptides needs more evidence to support this assumption.

A systematic review of cognitive event-related potentials in mild cognitive impairment and Alzheimer's disease

This systematic review examined whether event-related potentials (ERPs) during higher cognitive processing can detect subtle, early signs of neurodegenerative disease. Original, empirical studies retrieved from PsycINFO and PubMed were reviewed if they analyzed patterns in cognitive ERPs (≥150 ms post-stimulus) differentiating mild cognitive impairment (MCI), Alzheimer's disease (AD), or cognitively intact elders who carry AD risk through the Apolipoprotein-E ε4 allele (ε4+) from healthy older adult controls (HC). The 100 studies meeting inclusion criteria (MCI = 47; AD = 47; ε4+ = 6) analyzed N200, P300, N400, and occasionally, later components. While there was variability across studies, patterns of reduced amplitude and delayed latency were apparent in pathological aging, consistent with AD-related brain atrophy and cognitive impairment. These effects were particularly evident in advanced disease progression (i.e., AD > MCI) and in later ERP components measured during complex tasks. Although ERP studies in intact ε4+ elders are thus far scarce, a similar pattern of delayed latency was notable, along with a contrasting pattern of increased amplitude, consistent with compensatory neural activation. This limited work suggests ERPs might be able to index early neural changes indicative of future cognitive decline in otherwise healthy elders. As ERPs are also accessible and affordable relative to other neuroimaging methods, their addition to cognitive assessment might substantively enhance early identification and characterization of neural dysfunction, allowing opportunity for earlier differential diagnosis and targeting of intervention. To evaluate this possibility there is urgent need for well-powered studies assessing late cognitive ERPs during complex tasks, particularly in healthy elders at risk for cognitive decline.

Increased local switch costs in mild cognitive impairment

Task switching performance was assessed in a group of healthy young, healthy old, and MCI-diagnosed participants. Highly significant RT-related local switch costs were found in the MCI group. This contrasts the typical finding that in normal aging local switch costs show no age-related deficit. Local switch costs deficits may be a diagnostic tool in differentiating normal and pathological cognitive aging.

The Role of Physical Fitness in Cognitive-Related Biomarkers in Persons at Genetic Risk of Familial Alzheimer's Disease

Introduction: Nondemented people with a family history of Alzheimer’s disease (ADFH) and the ApoE-4 allele have been demonstrated to show a trend for a higher probability of cognitive decline and aberrant levels of cognitive-related biomarkers. However, the potential interactive effects on physical fitness have not been investigated. Purpose: The primary purpose of this study was to determine whether ADFH individuals with the ApoE-4 genotype show deviant brain event-related neural oscillatory performance and cognitively-related molecular indices. A secondary purpose was to examine the interactive effects on physical fitness. Methods: Blood samples were provided from 110 individuals with ADFH to assess molecular biomarkers and the ApoE genotype for the purpose of dividing them into an ApoE-4 group (n = 16) and a non-ApoE-4 group (n = 16) in order for them to complete a visuospatial working memory task while simultaneously recording electroencephalographic signals. They also performed a senior functional physical fitness (SFPF) test. Results: While performing the cognitive task, the ApoE-4 relative to non-ApoE-4 group showed worse accuracy rates (ARs) and brain neural oscillatory performance. There were no significant between-group differences with regard to any molecular biomarkers (e.g., IL-1β, IL-6, IL-8, BDNF, Aβ1-40, Aβ1-42). VO_2max was significantly correlated with the neuropsychological performance (i.e., ARs and RTs) in the 2-item and 4-item conditions in the ApoE-4 group and across the two groups. However, the electroencephalogram (EEG) oscillations during visuospatial working memory processing in the two conditions were not correlated with any SFPF scores or cardiorespiratory tests in the two groups. Conclusions: ADFH individuals with the ApoE-4 genotype only showed deviant neuropsychological (e.g., ARs) and neural oscillatory performance when performing the cognitive task with a higher visuospatial working memory load. Cardiorespiratory fitness potentially played an important role in neuropsychological impairment in this group.

Distinctive Effects of Aerobic and Resistance Exercise Modes on Neurocognitive and Biochemical Changes in Individuals with Mild Cognitive Impairment

Background:

Decreased levels of the neuroprotective growth factors, low-grade inflammation, and reduced neurocognitive functions during aging are associated with neurodegenerative diseases, such as Alzheimer’s disease. Physical exercise modifies these disadvantageous phenomena while a sedentary lifestyle promotes them.

Purpose:

The purposes of the present study included investigating whether both aerobic and resistance exercise produce divergent effects on the neuroprotective growth factors, inflammatory cytokines, and neurocognitive performance, and further exploring whether changes in the levels of these molecular biomarkers are associated with alterations in neurocognitive performance.

Methods:

Fifty-five older adults with amnestic MCI (aMCI) were recruited and randomly assigned to an aerobic exercise (AE) group, a resistance exercise (RE) group, or a control group. The assessment included neurocognitive measures [e.g., behavior and event-related potential (ERP)] during a task-switching paradigm, as well as circulating neuroprotective growth factors (e.g., BDNF, IGF-1, VEGF, and FGF-2) and inflammatory cytokine (e.g., TNF-α, IL-1β, IL-6, IL-8, and IL-15) levels at baseline and after either a 16-week aerobic or resistance exercise intervention program or a control period.

Results:

Aerobic and resistance exercise could effectively partially facilitate neurocognitive performance [e.g., accuracy rates (ARs), reaction times during the heterogeneous condition, global switching cost, and ERP P3 amplitude] when the participants performed the task switching paradigm although the ERP P2 components and P3 latency could not be changed. In terms of the circulating molecular biomarkers, the 16-week exercise interventions did not change some parameters (e.g., leptin, VEGF, FGF-2, IL-1β, IL-6, and IL-8). However, the peripheral serum BDNF level was significantly increased, and the levels of insulin, TNF-α, and IL-15 levels were significantly decreased in the AE group, whereas the RE group showed significantly increased IGF-1 levels and decreased IL-15 levels. The relationships between the changes in neurocognitive performance (AR and P3 amplitudes) and the changes in the levels of neurotrophins (BDNF and IGF-1)/inflammatory cytokines (TNF-α) only approached significance.

Conclusion:

These findings suggested that in older adults with aMCI, not only aerobic but also resistance exercise is effective with regard to increasing neurotrophins, reducing some inflammatory cytokines, and facilitating neurocognitive performance. However, the aerobic and resistance exercise modes likely employed divergent molecular mechanisms on neurocognitive facilitation.

A Single-Channel EEG-Based Approach to Detect Mild Cognitive Impairment via Speech-Evoked Brain Responses

Mild cognitive impairment (MCI) is the preliminary stage of dementia, which may lead to Alzheimer's disease (AD) in the elderly people. Therefore, early detection of MCI has the potential to minimize the risk of AD by ensuring the proper mental health care before it is too late. In this paper, we demonstrate a single-channel EEG-based MCI detection method, which is cost-effective and portable, and thus suitable for regular home-based patient monitoring. We collected the scalp EEG data from 23 subjects, while they were stimulated with five auditory speech signals. The cognitive state of the subjects was evaluated by the Montreal cognitive assessment test (MoCA). We extracted 590 features from the event-related potential (ERP) of the collected EEG signals, which included time and spectral domain characteristics of the response. The top 25 features, ranked by the random forest method, were used for classification models to identify subjects with MCI. Robustness of our model was tested using leave-one-out cross-validation while training the classifiers. Best results (leave-one-out cross-validation accuracy 87.9%, sensitivity 84.8%, specificity 95%, and F score 85%) were obtained using support vector machine (SVM) method with radial basis kernel (RBF) (sigma = 10/cost = 10² ). Similar performances were also observed with logistic regression (LR), further validating the results. Our results suggest that single-channel EEG could provide a robust biomarker for early detection of MCI.

Physical Exercise with Music Maintains Activities of Daily Living in Patients with Dementia: Mihama-Kiho Project Part 21

BACKGROUND

Recent studies suggest that combined non-pharmacological interventions are more beneficial than single interventions for primary and secondary prevention of dementia. We previously reported enhanced effects of physical exercise with music (ExM) on cognitive function in normal elderly people compared to exercise alone.

OBJECTIVE

To identify if ExM improves cognitive function and activities of daily livings (ADLs) in dementia patients over cognitive stimulation (CS).

METHODS

We enrolled 85 patients with mild to moderate dementia. Forty-three subjects performed ExM developed by the Yamaha Music Foundation, and 42 subjects performed cognitive stimulation using portable game consoles and drills involving easy calculations, mazes, and mistake-searching in pictures. Interventions were performed once a week for 40 minutes. Before and after the six-month intervention, patients were assessed using neuropsychological batteries, and ADLs were assessed by patients' caregivers using the functional independence measure (FIM). Voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) was used to assess medial temporal lobe atrophy.

RESULTS

Twenty-three subjects dropped out during the intervention. Thirty-one patients from each group were analyzed. Post-intervention, both groups showed significantly improved visuospatial function. Significant benefits were observed in psychomotor speed or memory in the ExM or CS groups, respectively. FIM scores, reflecting ADLs, and VSRAD scores were significantly preserved in the ExM group, but significantly worsened in the CS group.

CONCLUSIONS

ExM produced greater positive effects on cognitive function and ADLs in patients with mild to moderate dementia than CS, excluding memory. Optimal interventions for dementia will likely be achieved by combining ExMand CS.

An acute bout of aerobic or strength exercise specifically modifies circulating exerkine levels and neurocognitive functions in elderly individuals with mild cognitive impairment

Although exercise is an effective way to decrease the risk of developing Alzheimer's disease, the biological basis for such benefits from the different exercise modes remains elusive. The present study thus aimed (i) to investigate the effects of acute aerobic or resistance exercise on neurocognitive performances and molecular markers when performing a cognitive task involving executive functioning in older adults with amnestic mild cognitive impairment (aMCI), and (ii) to explore relationships of acute exercise-induced neurocognitive changes with changes in circulating levels of neuroprotective growth factors (e.g., BDNF, IGF-1, VEGF, and FGF-2, collectively termed 'exerkines'), elicited by different acute exercise modes. Sixty-six older adults with aMCI were recruited and randomly assigned to an aerobic exercise (AE) group, a resistance exercise (RE) group, or a non-exercise-intervention (control) group. The behavioral [i.e., accuracy rate (AR) and reaction time (RT)] and electrophysiological [i.e., event-related potential (ERP) P3 latency and amplitude collected from the Fz, Cz, and Pz electrodes] indices were simultaneously measured when participants performed a Flanker task at baseline and after either an acute bout of 30 min of moderate-intensity AE, RE or a control period. Blood samples were taken at three time points, one at baseline (T1) and two after an acute exercise intervention (T2 and T3: before and after cognitive task test, respectively). The results showed that the acute AE and RE not only improved behavioral (i.e., RTs) performance but also increased the ERP P3 amplitudes in the older adults with aMCI. Serum FGF-2 levels did not change with acute aerobic or resistance exercise. However, an acute bout of aerobic exercise significantly increased serum levels of BDNF and IGF-1 and tended to increase serum levels of VEGF in elderly aMCI individuals. Acute resistance exercise increased only serum IGF-1 levels. However, the exercise-induced elevated levels of these molecular markers returned almost to baseline levels in T3 (about 20 min after acute exercise). In addition, changes in the levels of neurotrophic and angiogenic factors were not correlated with changes in RTs and P3 amplitudes. The present findings of changes in neuroprotective growth factors and neurocognitive performances through acute AE or RE suggest that molecular and neural prerequisites for exercise-dependent plasticity are preserved in elderly aMCI individuals. However, the distinct pattern of changes in circulating molecular biomarkers induced by two different exercise modes in aMCI elderly individuals and the potentially interactive mechanisms of the effects of BDNF, IGF-1, and VEGF on amyloid-β provide a basis for future long-term exercise intervention to investigate whether AE relative to RE might be more effective in prevention/treatment of an early stage neurodegenerative disease.