Group Of Healthy Adults Research Articles

The Effect of an Intervention to Increase Fruit and Vegetable Intake on Skin Carotenoid Scores

Our study aimed to increase consumption of fruits and vegetables (F/V) in a group of healthy adults and to measure skin carotenoid levels. Thirty-three medical students were asked to increase their F/V intake to 4 to 6 cups per day during an 8-week intervention period. Students were given a list of F/V high in antioxidants and a $50 gift card every 2 weeks to purchase the food items. Fruits and vegetables intake and skin carotenoid levels were measured using resonance Raman spectroscopy. All students were successful in increasing F/V intake and skin carotenoid levels. However, students with lower baseline skin carotenoid levels may not be so effective in maintaining higher levels.

Hydration biomarkers and copeptin: relationship with ad libitum energy intake, energy expenditure, and metabolic fuel selection.

Background/ObjectiveEvidence from non-human species indicate that hydration and arginine vasopressin (AVP) influence fuel selection, energy expenditure (EE), and food intake, but these relationships are unclear in humans. We sought to assess whether hydration biomarkers [24-h urine volume (UVol) and urine urea nitrogen concentration (UUN)] and copeptin (a surrogate for AVP) are associated with 24-h EE, respiratory quotient (RQ), and daily energy intake (DEI).Subjects/MethodsIn a secondary analysis of collected data, we selected healthy adults (Group 1, n = 177) who had 24-h whole-room indirect calorimetry measurements in energy balance with 24-h urine collection and fasting copeptin measurements (n=117), followed by 3 days ad libitum food intake. A separate group (Group 2, n=284) with hydration markers and calorimetry measurements was also studied. The main outcome measures were 24-h RQ, 24-h EE, DEI, substrate oxidation.ResultsIn Group 1, lower 24-h UVol and higher 24-h UUN, indicating lower hydration, were correlated with lower 24-h RQ (r = 0.35, p <0.0001, and r = −0.29, p = 0.0001, respectively; results similar in Group 2) and predicted subsequent reduced DEI (r = 0.20, p = 0.01, and r = −0.27, p = 0.0003, respectively), adjusted for confounders. Copeptin was independently associated with 24-h lipid oxidation (r = −0.23, p = 0.01). In Group 2, lower hydration was associated with reduced 24-h EE (24-h UVol: r = 0.29, p <0.0001; 24-h UUN: r = −0.25, p <0.0001).ConclusionsHydration biomarkers were associated with metabolic differences characterized by altered food intake, fuel selection, and possibly EE. Independently, copeptin was associated with higher lipid oxidation.

Comparison of Oxygen Uptake Kinetics Between Kidney Transplant Recipients and Healthy Subjects

Aerobic exercise capacity is reduced in kidney transplant recipients (KTRs), with a progressive improvement after transplantation. KTRs show central exercise limiting factors such as chronotropic incompetence, anemia, heart or vascular diseases. Moreover, peripheral alterations at a muscular level are present in this population. It has been reported that slower oxygen uptake (VO2)-kinetics during a moderate constant load exercise, expressed as an increased time constant (τ), may reflect an impaired muscular oxidative metabolism. PURPOSE: To analyze the VO2-kinetics in a population of KTRs. METHODS: two groups of KTRs enrolled 3 and 12 months (n=21 and 14, respectively) after transplantation and a control group of healthy young adults (n=16) underwent cardiopulmonary exercise testing at cycle-ergometer. The protocol consisted in two subsequent constant, moderate-load exercise phases with a final incremental test until exhaustion. RESULTS: The τ was increased in KTRs compared to controls (50.4±13.11 s at 3 and 43.84±11.57 s at 12 months vs 28.91±8.37 s in controls; both P<0.01) while VO2peak was reduced, but significantly higher in the group evaluated at 12 months (21.30±4.34 vs 26.36±7.96 ml/kg/min (P=0.04), vs 41.7±7.82 ml/kg/min in controls (both P<0.01)). Consistently with this result, an increased hemoglobin (Hb) concentration was found 12 months after transplantation (12.77±1.67 vs 14.55±1.74 g/dL (P<0.01)). Also, lower peak heart rate (HR) might affect KTRs’ exercise capacity (79.67±12.16% of predicted at 3 and 84.29±11.49% at 12 months vs. 93.38±5.21% in controls; both P≤0.01). Among KTRs, the τ showed a moderate negative correlation with VO2peak and oxygen uptake efficiency slope (R=-0.51 and R=-0.57, respectively), less depending on Hb and particularly on peak HR (R=-0.33 and R=-0.13, respectively). CONCLUSION: KTRs show slower VO2-kinetics, reduced peak VO2 and HR when compared to a population of healthy young adults. VO2peak and Hb seem to improve during the first year after transplantation. The reduced aerobic capacity of KTRs was associated with slower VO2-kinetics, which seem to be less affected by the oxygen transport. These findings suggest that an impaired oxidative muscle metabolism could be a peripheral limiting factor contributing to decreased exercise capacity in KTRs.

Corticospinal excitability for flexor carpi radialis decreases with baroreceptor unloading during intentional co-contraction with opposing forearm muscles.

Concurrent activation of antagonistic muscles (co-contraction) is used for stiffening a joint, whereas its neural control under hemodynamic stress (e.g., posture change, high gravity, and hemorrhage) is unknown. Corticospinal excitability during co-contraction may be altered with baroreceptor unloading due to potential modulations in spinal and/or inhibitory pathways (e.g., disynaptic group I inhibition and GABA-mediated intracortical inhibition). The purpose of this study was to understand the effect of baroreceptor unloading on corticospinal excitability during co-contraction in humans. Motor evoked potential and cortical silent period in a wrist flexor muscle were examined using transcranial magnetic stimulation in two groups of healthy young adults. All subjects performed isometric contraction of the wrist flexors (flexion) and co-contraction of the wrist flexors and extensors (co-contraction). Spinal disynaptic inhibition was also assessed with the ratio of H-reflex responses to unconditioned and conditioned electrical stimulations of the peripheral nerves for the muscles. In one of the groups, baroreflex unloading was induced by applying lower body negative pressure. There was no significant effect of baroreflex unloading on cortical silent period or H-reflex measure of disynaptic inhibition. With baroreflex unloading, motor evoked potential area in the flexor carpi radialis was decreased during co-contraction but not during flexion. The results indicated that baroreceptor unloading decreases corticospinal excitability during co-contraction of antagonistic muscles, apparently by influencing neural pathways that were not probed with cortical silent period or spinal disynaptic inhibition.

Cerebral Autoregulation Evidenced by Synchronized Low Frequency Oscillations in Blood Pressure and Resting-State fMRI.

Resting-state functional magnetic resonance imaging (rs-fMRI) is a widely used technique for mapping the brain’s functional architecture, so delineating the main sources of variance comprising the signal is crucial. Low frequency oscillations (LFO) that are not of neural origin, but which are driven by mechanisms related to cerebral autoregulation (CA), are present in the blood-oxygenation-level-dependent (BOLD) signal within the rs-fMRI frequency band. In this study we use a MR compatible device (Caretaker, Biopac) to obtain a non-invasive estimate of beat-to-beat mean arterial pressure (MAP) fluctuations concurrently with rs-fMRI at 3T. Healthy adult subjects (n = 9; 5 male) completed two 20-min rs-fMRI scans. MAP fluctuations were decomposed into different frequency scales using a discrete wavelet transform, and oscillations at approximately 0.1 Hz show a high degree of spatially structured correlations with matched frequency fMRI fluctuations. On average across subjects, MAP fluctuations at this scale of the wavelet decomposition explain ∼2.2% of matched frequency fMRI signal variance. Additionally, a simultaneous multi-slice multi-echo acquisition was used to collect 10-min rs-fMRI at three echo times at 7T in a separate group of healthy adults (n = 5; 5 male). Multiple echo times were used to estimate the R2∗ decay at every time point, and MAP was shown to strongly correlate with this signal, which suggests a purely BOLD (i.e., blood flow related) origin. This study demonstrates that there is a significant component of the BOLD signal that has a systemic physiological origin, and highlights the fact that not all localized BOLD signal changes necessarily reflect blood flow supporting local neural activity. Instead, these data show that a proportion of BOLD signal fluctuations in rs-fMRI are due to localized control of blood flow that is independent of local neural activity, most likely reflecting more general systemic autoregulatory processes. Thus, fMRI is a promising tool for studying flow changes associated with cerebral autoregulation with high spatial resolution.

Diagnostic precision of the Wisconsin Card Sorting Test in assessing cognitive deficits in substance use disorders

The Wisconsin Card Sorting Test (WCST) is a widely used neuropsychological instrument to assess executive functions related to cognitive flexibility and abstract reasoning. However, there is a lack of studies investigating the diagnostic precision of this instrument in substance use disorders. In this study, we aimed at assessing the sensitivity and specificity of the WCST in discriminating the performance of participants with substance use disorder with cognitive deficits and participants from the general population without cognitive deficits. The sample comprised three groups of participants with substance use disorders (opioid use disorder in harm reduction with methadone maintenance; opioid use disorder in treatment in a therapeutic community; alcohol use disorder in a therapeutic community) and a normative group of healthy adults. The total sample consisted of 587 participants that were assessed with cognitive tests for executive functions, general cognitive functioning, and self-reported depression. The results showed differences between groups in most WCST variables, providing evidence of discriminant validity for this test. Convergent validity was also established by weak to moderate correlations with general cognitive functioning. Cutoff points based on receiver operating characteristic (ROC) curves were calculated for the WCST variables. Overall, the WCST was sensitive to changes in cognitive flexibility and abstract reasoning that are key features of substance use disorders.

Enhancement of posterior brain functional networks in bilingual older adults

AbstractBilingualism has been said to improve cognition and even delay the onset of Alzheimer's disease (AD). This research aimed to investigate whether bilingualism leaves a neurophysiological trace even when people are highly educated. We expected bilinguals to present better preserved brain functional networks, which could be a trace of higher cognitive reserve. With this purpose, we conducted a magnetoencephalographic study with a group of healthy older adults. We estimated functional connectivity using phase-locking value and found five clusters in parieto-occipital regions in which bilinguals exhibited greater functional connectivity than monolinguals. These clusters included brain regions typically implicated in language processing. Furthermore, these functional changes correlated with caudate volumes (a key region in language shifting and control) in the bilingual sample. Interestingly, decreased Functional Connectivity between posterior brain regions had already been identified as an indicator of aging/preclinical AD but, according to our study, bilingualism seems to exert the opposite effect.

The effects of textured insoles on quiet standing balance in four stance types with and without vision

BackgroundWearing a textured shoe insole can decrease postural sway during static balance. Previous studies assessed bipedal and/or unipedal standing. In contrast, we aimed to investigate if textured insoles modulated postural sway during four stance types (bipedal, standard Romberg, tandem Romberg, and unipedal), with and without vision.MethodsThe repeated measures design involved 28 healthy young adults (13 females; mean age = 26.86 ± 6.6 yrs) performing quiet standing in the four stance types on a force platform, under two different insole conditions (textured insole; TI vs. smooth insole; SI), with eyes open and eyes closed. Postural sway was assessed via the range and standard deviation of the COP excursions in the anterior-posterior and medial-lateral sway, and overall mean velocity.ResultsThe main effect of insole type was statistically significant at the alpha p = 0.05 level (p = 0.045). Compared to smooth insoles, textured insoles reduced the standard deviation of anterior-posterior excursions (APSD). While simple main effect analyses revealed this was most pronounced during eyes closed bipedal standing, insole type did not provide a statistically significant interaction with either stance or vision in this measure, or any other. Postural sway showed statistically significant increases across both stance type (bipedal < standard Romberg < tandem Romberg < unipedal), and vision (eyes closed < eyes open), in almost all measures. Stance and vision did have a statistically significant interaction in each measure, reflecting greater postural disturbances with eyes closed when stance stability decreased.ConclusionsOverall, these results support textured insole use in healthy young adults to reduce postural sway measures. This is because APSD is an index of spatial variability, where a decrease is associated with improved balance and possibly translates to reduced falls risk. Placing a novel texture in the shoe presumably modulated somatosensory inputs. It is important to understand the underlying mechanisms by which textured insoles influence postural sway. As such, utilising a healthy adult group allows us to investigate possible mechanisms of textured insoles. Future research could investigate the potential underlying mechanisms of textured insole effects at a neuromuscular and cortical level, in healthy young adults.

Correlation Between Sleep-Time Masseter Muscle Activity and Tooth Wear: An Electromyographic Study.

To assess the correlation between tooth wear and sleep-time masseter muscle activity (sMMA) in a group of healthy young adults who underwent home electromyographic/electrocardiographic (EMG/ECG) recordings with a portable device. A total of 41 healthy volunteers (23 women, 18 men; mean age 28.8 years, range 25 to 40) with good natural dentition underwent a 2-night in-home evaluation with a portable device that allowed a simultaneous sleep-time recording of EMG signals from both masseter muscles and heart rate. The number of sleep bruxism (SB) episodes per sleep hour (SB index), the number of phasic, tonic, and mixed sMMA events per hour, and the total number of sMMA events per night were calculated. All individuals also underwent an assessment of tooth wear on digital casts with the adoption of a six-degree rating scale. Correlations between sMMA variables and tooth wear were assessed using Pearson test. The null hypothesis was that correlation between the two conditions would not be significant. On average, the SB index was 4.5 ± 2.6, while the total number of sleep-time masseter contractions was 97.2 ± 55.2. Of those contractions, almost 60% were phasic. Average tooth wear was 1.5 ± 0.7, with the canines and mandibular incisors showing the highest wear scores. For all pairwise analyses, correlation values were not significant (P values .11 to .69), with r values ranging from 0.064 to 0.253. The null hypothesis of an absence of correlation between tooth wear and sMMA could not be rejected, implying that tooth wear cannot be used as an indicator of ongoing SB or sMMA. Future studies taking into account the multifaceted nature of tooth wear and the complex natural course of sleep phenomena are encouraged to investigate the issue further, at the individual level.

Hand motor slowness in Parkinson disease patients performing Fitts task

Introduction: Most daily movements require a compromise between speed and accuracy. Parkinson’s disease (PD), is characterized by an inability to adapt movement control concerning task temporal and spatial constraints [1]. One of the most studied paradigms in movement control sciences is Fitts’ task [2]. Fitts’ law states that the amount of time required for a person to move a pen, from a target to another is a function of the distance between targets, and the target width. The longer the distance and the smaller the target’s width, the longer it takes, due to the existence of a speed-accuracy trade-off. This study aimed to compare the performance between PD subjects and healthy paired controls on a reciprocal tapping task. Materials and methods: Kinematics was assessed using a tri-axial accelerometer placed on the subjects preferred hand. Subjects were asked to perform continuously hand pointing movements between two identical targets of 1, or 2 cm width (W), separated by 2, 4, 8, or 16 cm (D), during 20 seconds. The task was performed in 5 different conditions with different Difficulty Indexes (DI = log2 (2D/W)). Data analysis included movement duration, number of movements, percentage of errors, and mean velocity and acceleration. The study was approved by ethics committee of Faculty of Human Kinetics. Informed consent was obtained from all subjects. Results: Nine people with PD formed the experimental group (EG), presenting UPDRS III score 26,4 (+/− 11,24); Hoehn and Yahr score 2, ON state). Nine age-matched healthy controls formed the control group (CG) (ages between 43 and 76 years). Mean velocity was significantly lower for the EG on DI 3 (p = 0.038) and 5 (p = 0.008). No significant differences in mean acceleration were found, although mean values tended to be lower on the EG. The increase of DI caused a decrease on the number of movements and a longer duration, in both groups. PD subjects consistently performed less movements (p < 0.05) with a greater percentage of errors (p < 0.05). Discussion and conclusions: This study, confirmed the existence of motor control differences between a group of people with PD and a healthy adults group. The results presented by the PD group, like in other studies, showed a tendency for smaller movement acceleration [3,4], a decrease in the speed of movement, which becomes more visible as the level of precision increases [1,3,4], a decrease in the number of movements, and a significant increase in the percentage of errors [3]. The fact that PD people were ON state during the assessment may have contributed to smaller differences in outcomes between the PD group and the healthy subjects.

A novel joint HCPMMP method for automatically classifying Alzheimer’s and different stage MCI patients

A 360-area surface-based cortical parcellation was recently generated using multimodal data in a group average of 210 healthy young adults from the Human Connectome Project (HCP). In order to automatically and accurately identify mild cognitive impairment (MCI) at its two levels (early MCI and late MCI), Alzheimer's disease (AD) and healthy control (HC), a novel joint HCP MMP method was first proposed to delineate the cortical architecture and function connectivity in a group of non healthy adults. The proposed method was applied to register a dataset of 96 resting-state functional connectomes from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to Connectivity Informatics Technology Initiative (CIFTI) space and parcellated brain into human connectome project multi-modal parcellation (HCPMMP) with 360 areas. Various network features in each node of the connectivity network were considered as the candidate features for classification.The fine-grained multi-modal based on HCP-MMP combined with machine learning in identification for EMCI, LMCI, AD and HC. Applying various network features, including strength, betweenness centrality, clustering coefficient, local efficiency, eigenvector centrality, etc, we trained and tested several machine learning models. Thousands of features were processed by filter and wrapper feature selection procedures, and finally there were thirty features to be selected to achieve classification accuracies of 93.8% for EMCI vs. HC, 95.8% for LMCI vs. HC, 95.8% for AD vs. HC, and 91.7% for LMCI vs. AD, respectively by using support vector machine (SVM) algorithm. Most of the selected features locate in the region of temporal or cingulate cortex. Compared with previous studies, our results demonstrate the superiority of the proposed method over existing techniques.

Physical activity and age-related biomechanical risk factors for knee osteoarthritis

BackgroundKnee osteoarthritis (OA) is a highly prevalent disease leading to mobility disability in the aged that could, in part, be initiated by age-related alterations in knee mechanics. However, if and how knee mechanics change with age remains unclear. Research questionWhat are the impacts of age and physical activity (PA) on biomechanical characteristics that can affect the loading environment in the knee during gait? MethodsThree groups (n = 20 each, 10 male and 10 female) of healthy adults were recruited: young (Y, 21–35 years), mid-life highly active (MHi, 55–70 years, runners), and mid-life less active (MLo, 55–70 years, low PA). Outcome measures included knee kinematics and kinetics and co-activation during gait, and knee extensor muscle torque and power collected at baseline and after a 30-minute treadmill trial to determine the impact of prolonged walking on knee function. ResultsAt baseline, high-velocity concentric knee extensor power was lower for MLo and MHi compared with Y, and MLo displayed greater early (6.0 ± 5.8 mm) and peak during stance (11.3 ± 7.8 mm) femoral anterior displacement relative to the tibia compared with Y (0.2 ± 5.6 and 4.4 ± 6.8 mm). Also at baseline, MLo showed equal quadriceps:hamstrings activation, while Y showed greater relative hamstrings activation during midstance. The walking bout induced substantial knee extensor fatigue (decrease in maximal torque and power) in Y and MLo, while MHi were fatigue-resistant. SignificanceThese results indicate that maintenance of PA in mid-life may impart small but measurable effects on knee function and biomechanics that may translate to a more stable loading environment in the knee through mid-life and thus could reduce knee OA risk long-term.

Changes in expression of p53 and inflammatory factors in patients with ulcerative colitis.

Ulcerative colitis (UC) is an important risk factor for the occurrence of colon cancer, and changes in expression of p53 and inflammatory factors are closely related to the pathogenesis of colon cancer. Therefore, changes in expression of p53 and inflammatory factors in UC were investigated to explore its intrinsic pathogenetic laws. The levels of inflammatory factors, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-10 and IL-4, in peripheral blood of UC patients and healthy adults were detected via enzyme-linked immunosorbent assay, and the changes in p53 expression were analyzed via immunohistochemistry and western blotting, and the correlation of p53 expression with changes in cytokines was also analyzed. Moreover, changes in 45S preribosomal ribonucleic acid (preRNA) transcriptional activity in four kinds of cell lines exposed to IL-6 were analyzed and determined by using reverse transcription-quantitative polymerase chain reaction. Finally, the C-myc protein expression after IL-6 stimulation was analyzed and evaluated via western blot analysis. The levels of IL-6 and TNF-α in peripheral blood in the UC patient group were significantly increased compared with those in the healthy adult group (P<0.01), while the levels of IL-10 and IL-4 in peripheral blood were significantly decreased compared with those in the healthy adult group (P<0.01). The p53 expression had a significant negative correlation with IL-6. The results showed that IL-6 activated C-myc messenger RNA (mRNA) translation, thereby upregulating the ribosomal RNA (rRNA) transcription. Additionally, IL-6 stimulated the mouse double minute 2 homolog (MDM2)-mediated proteasomal degradation of p53 by reducing the availability of ribosomal protein used for MDM2 binding, thus resulting in the downregulation of p53 protein expression. The findings of the study show that, expression level of IL-6 was increased in UC patients, which regulates the downregulation of p53 expression level and plays a role in tumorigenesis through enhancing cell proliferation and inhibiting apoptosis.

Mindfulness Induces Changes in Anterior Alpha Asymmetry in Healthy Older Adults

Anterior alpha asymmetry is an EEG measure of relative left- or right-sided prefrontal cortical activity that has been associated with affective style, such that greater relative left-sided activity is associated with positive affect and approach-related behaviours. While mindfulness has been shown to enhance attention and affect, here we investigate the underlying neurobiological changes supporting these outcomes by assessing anterior alpha asymmetry. A longitudinal RCT was conducted to investigate the effect of an 8-week mindfulness training (MT) intervention on anterior alpha asymmetry and affect in a group of healthy adults aged over 60 years (n = 41). An active control computer-based attention training (CT) program (n = 26) designed to activate similar attentional components to mindfulness was used to determine if outcomes resulted from attention training or mindfulness-specific factors. The Sustained Attention to Response Task was used to assess attentional performance, while a breath counting task was used to classify mindfulness participants into high (MT-HIGH; n = 19) and low (MT-LOW; n = 22) proficiency groups. While all groups displayed improved attentional performance, only the MT-HIGH and MT-LOW groups showed significant increases in positive affect as measured by the Positive and Negative Affect Schedule. The MT-HIGH group showed significantly increased relative left-sided activity at both Fp1/Fp2 and F3/F4 electrode pairs, while no significant changes were observed in the MT-LOW and CT groups. These results suggest that 8 weeks of mindfulness training is capable of inducing changes in resting anterior alpha asymmetry, but these results are dependent upon the level of proficiency achieved.

The neural sources of N170: Understanding timing of activation in face-selective areas.

The N170 ERP component has been widely identified as a face-sensitive neural marker. Despite extensive investigations conducted to examine the neural sources of N170, there are two issues in prior literature: (a) few studies used individualized anatomy as head model for the cortical source analysis of the N170, and (b) the relationship between the N170 and face-selective regions from fMRI studies is unclear. Here, we addressed these questions by presenting pictures of faces and houses to the same group of healthy adults and recording structural MRI, fMRI, and high-density ERPs in separate sessions. Source analysis based on the participant's anatomy showed that the middle and posterior fusiform gyri were the primary neural sources for the face-sensitive aspects of the N170. Source analysis based on regions of interest from the fMRI revealed that the fMRI-defined fusiform face area was the major contributor to the N170. The current study suggests that the fusiform gyrus is a major neural contributor to the N170 ERP component and provides further insights about the spatiotemporal characteristics of face processing.

WATER-BASED EXERCISE AND RESISTANCE TRAINING IMPROVE COGNITION IN OLDER ADULTS

ABSTRACT Introduction: Physical exercise has been associated with maintenance of physical abilities and the reduction of age-related cognitive decline, and is considered both a low-cost primary prevention strategy and a non-pharmacological treatment of cognitive dysfunction in older people. However, the contribution of each type of physical exercise to the cognitive health of the elderly population has not yet been fully investigated. Objective: This study investigated the possible influences of water-based and resistance training exercises on the cognitive performance of healthy older adults in automated tests, and investigated which test(s) would be the most effective indicator of differences in aging cognitive performance. Methods: Three groups of community-dwelling healthy older adults: water-based exercise group, resistance training group and sedentary group, were assessed using an automated set of neuropsychological tests (CANTAB) and tests to assess functional exercise capacity. Results were compared by one-way analysis of variance (ANOVA) and Pearson linear correlation. Results: The water-based exercise group had the best functional exercise capacity scores and the best performance in the reaction time evaluation (response and movement latencies). The resistance training group had less movement latency than the sedentary group. Functional mobility was positively correlated with response and movement latency. Conclusions: Taken together our findings show that physical exercise contributes to the preservation of cognitive function in healthy older adults and that water-based exercise has better results than resistance training in terms of reaction time. Moreover, the changes related to reaction time function were detected before the changes in working memory functions, sustained attention and learning in the sedentary participants, suggesting that this variable could be an early sensitive indicator of subtle cognitive changes associated with aging. Level of Evidence II; Retrospective study.

Relationship Between DTI Metrics and Cognitive Function in Alzheimer's Disease.

Introduction: Alzheimer’s disease (AD) is a neurodegenerative disorder with a clinical presentation characterized by memory impairment and executive dysfunction. Our group previously demonstrated significant alterations in white matter microstructural metrics in AD compared to healthy older adults. We aimed to further investigate the relationship between white matter microstructure in AD and cognitive function, including memory and executive function.Methods: Diffusion tensor imaging (DTI) and neuropsychological data were downloaded from the AD Neuroimaging Initiative database for 49 individuals with AD and 48 matched healthy older adults. The relationship between whole-brain fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AxD), radial diffusivity (RD), and composite scores of memory and executive function was examined. We also considered voxel-wise relationships using Tract-Based Spatial Statistics.Results: As expected, individuals with AD had lower composite scores on tests of memory and executive function, as well as disrupted white matter integrity (low FA, high MD, AxD, and RD) relative to healthy older adults in widespread regions, including the hippocampus. When the AD and healthy older adult groups were combined, we found significant relationships between DTI metrics (FA/MD/AxD/RD) and memory scores across widespread regions of the brain, including the medial temporal regions. We also found significant relationships between DTI metrics (FA/MD/AxD/RD) and executive function in widespread regions, including the frontal areas in the combined group. However, when the groups were examined separately, no significant relationships were found between DTI metrics (FA/MD/AxD/RD) and memory performance for either group. Further, we did not find any significant relationships between DTI metrics (FA/MD/AxD/RD) and executive function in the AD group, but we did observe significant relationships between FA/RD, and executive function in healthy older adults.Conclusion: White matter integrity is disrupted in AD. In a mixed sample of AD and healthy elderly persons, associations between measures of white matter microstructure and memory and executive cognitive test performance were evident. However, no significant linear relationship between the degree of white matter disruption and level of cognitive functioning (memory and executive abilities) was found in those with AD. Future longitudinal studies of the relations between DTI metrics and cognitive function in AD are required to determine whether DTI has potential to measure progression of AD and/or treatment efficacy.

Wheelchair Seating: Peak Pressure Distribution in Young versus Elderly Healthy Controls

Background: People may use a wheelchair when they need assistance with mobility. Some users have to remain seated in their wheelchair for most of their awake time and for a lot of activities. The need for a well fitted and supportive wheelchair is important and, for those who use the wheelchair for many hours, peak pressure distribution is of interest to prevent pressure ulcers and discomfort. Aim: To describe how high local peak pressures may be distributed over risk areas for pressure ulcers in different wheelchair settings. Methods: Two groups of healthy adults were recruited (40 elderly and 30 younger individuals). Two standard models of manual wheelchairs were used together with two types of wheelchair cushions. Results: The elderly group had a higher peak pressure over the ischial tuberosity and increased posterior pelvic rotation in the shaped seat cushion. Both groups had higher peak pressure over the trochanter in the shaped seat cushion. Peak pressure was also higher over the coccyx for the elderly in the shaped seat cushion compared with the plain cushion; this was lower for the younger group. Discussion: The results indicate that age might influence the important physical prerequisites when fitting a wheelchair to an individual.

Use of the model of Inner Strength for analysing reflective interviews in a group of healthy middle-aged adults.

Objective:Inner Strength has been described as a human resource that promotes well-being linked to health. The aim of this study was to explore how Inner Strength and its four dimensions are manifested in interviews in a group of middle-aged healthy women and men.Methods:Retrospective reflective interviews with middle-aged healthy women (n = 5) and men (n = 4) selected from a population study were content analysed deductively.Results:The following themes and their constituents were found in the respective dimensions of the Model of Inner Strength. Firmness: having a drive to act, being purposeful, having trust in one’s competence, and having a positive view of life. Connectedness: being in community, receiving and giving support, and, receiving and giving care. Creativity: changing unsatisfactory life situations, seeing new opportunities, and realizing dreams. Stretchability: balancing between options, and extending oneself.Conclusions:Expressions that were interpreted as belonging to Inner Strength could be referred the different dimensions of Inner Strength. The Model of Inner Strength is suitable for analysing Inner Strength among middle-aged men and women. The findings indicate that Inner Strength can be identified in human beings’ narratives if asked for.

The effect of Beta-tACS on the consolidation of motor memory

Event Abstract Back to Event The effect of Beta-tACS on the consolidation of motor memory Liliia Roshchupkina1*, Whitney Stee1, Tommaso Faret2 and Philippe Peigneux1 1 Free University of Brussels, Belgium 2 University of Florence, Italy Motor memory consolidation is a non-linear process with critical time periods after the end of training, as evidenced by fluctuations in levels of behavioral performance. It was shown that 5 to 30 minutes (boost period) after the end of the initial learning stage, spontaneous performance gains are observed in the absence of supplementary training. This short-lived boost period presumably reflects fast synaptic consolidation processes, and constitutes an important prerequisite for subsequent successful consolidation steps. When measured 4 hours after learning (silent period) performance is not improved, and 30-minutes boost levels were shown to correlate with performance 24 hours later, indicating a link between boost and the long-term consolidation of motor memory traces. The neuronal plastic changes subtending the consolidation of the motor memories are taking place both within the primary motor cortex (M1) and subcortical loops, and synchronized oscillatory activity between brain areas within this motor network plays a crucial role in memory stabilization. Transcranial alternating current stimulation (tACS) is able to entrain the brain’s oscillatory activity, hereby affecting cognitive processing and influencing brain plasticity. Previous studies showed that 20 Hz stimulation over the primary motor cortex during the boost period facilitates motor memory consolidation. However, till our knowledge, no study investigated the long-scale effects of tACS and its relation to the boost (30 min) and silent (4h) post-training periods and overnight performance gains. We hypothesized here that 20 Hz tACS delivered over M1 immediately after learning (1) may synchronize activity within related neuronal networks and improve -performance; (2) that an additional stimulation session at the end of the boost period (30’) would further increase performance; (3) and that an extra stimulation administered within the silent period (4h) would facilitate long lasting changes that may or may not be behaviorally overt after subsequent nocturnal sleep (24h later the initial learning). Five groups of healthy young adults were trained on the finger tapping motor task (FTT) and then exposed to tACS or sham stimulation immediately and at 30 min or 4h, then were tested behaviorally 24h later. Performance was calculated as the percentage of improvement from the end of learning to the test session. Our results showed improved performance from learning to test sessions, but no significant interactions with the stimulation conditions. These results suggest that 20 Hz tACS applied over M1 after motor learning does not markedly impact on the consolidation of motor memories. Future studies are needed to determine whether tACS-related improvement might be observed with different stimulation parameters, brain localization and/or time periods. Keywords: Motor memory consolidation, boost effect, tACS (transcranial alternating current stimulation), performance, Sleep Conference: 13th National Congress of the Belgian Society for Neuroscience , Brussels, Belgium, 24 May - 24 May, 2019. Presentation Type: Poster presentation Topic: Behavioral/Systems Neuroscience Citation: Roshchupkina L, Stee W, Faret T and Peigneux P (2019). The effect of Beta-tACS on the consolidation of motor memory. Front. Neurosci. Conference Abstract: 13th National Congress of the Belgian Society for Neuroscience . doi: 10.3389/conf.fnins.2019.96.00068 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Apr 2019; Published Online: 27 Sep 2019. * Correspondence: Mrs. Liliia Roshchupkina, Free University of Brussels, Brussels, Belgium, roshchupkinaliliia@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Liliia Roshchupkina Whitney Stee Tommaso Faret Philippe Peigneux Google Liliia Roshchupkina Whitney Stee Tommaso Faret Philippe Peigneux Google Scholar Liliia Roshchupkina Whitney Stee Tommaso Faret Philippe Peigneux PubMed Liliia Roshchupkina Whitney Stee Tommaso Faret Philippe Peigneux Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.