Objective: To evaluate and compare the effects of conventional proprioceptive training and games with motion monitoring on plantar tactile sensitivity in older women.
Methods: A randomized controlled clinical trial, with 50 older women randomized into three groups: conventional proprioception (n = 17), games with motion monitoring (n = 16), and the control (n = 17). They underwent 24 intervention sessions, three times a week, for eight weeks.
An analytical method for the simultaneous determination of nine prohibited -nitrosamines in cosmetic products is presented. -nitrosamines are banned compounds in cosmetic products due to their harmful effects. Therefore, these compounds are not intentionally added to these products but, however, small amounts of them may be present due to unintentional causes, and thus sensitive methods for their analytical control are required.
View Article and Find Full Text PDFIn the body of research on the relationship between gesture and speech, some models propose they form an integrated system while others attribute gestures a compensatory role in communication. This study addresses the gesture-speech relationship by taking disfluency phenomena as a case study. Since it is part of a project aimed at designing virtual agents to be employed in museums, an analysis was performed on the communicative behavior of tourist guides.
View Article and Find Full Text PDFAn analytical method for the determination of residual acrylamide in cosmetic products containing potential acrylamide-releasing ingredients is presented. The method is based on vortex-assisted reversed-phase dispersive liquid-liquid microextraction (VA-RP-DLLME) to extract and preconcentrate acrylamide by using water as extraction solvent taking advantage the highly polar behavior of this analyte, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for its determination. Under optimized conditions (5 mL toluene as supporting solvent, 50 µL of water as extraction solvent, 1 min for vortex extraction time) the method was properly validated obtaining good analytical features (linearity up to 20 ng mL, method limits of detection and quantification of 0.
View Article and Find Full Text PDFBackground: Human gait is a complex task resulting from the interaction of sensory perception, muscle force output, and sensory-motor integration, which declines with the aging process and impacts gait speed in older women.
Research Question: What are the separate and combined impacts of sensory-motor factors on gait speed of older women?
Methods: Sixty healthy older women (69.3 ± 5.
Arch Gerontol Geriatr
December 2020
Purpose: This study aimed to compare heart rate variability (HRV) parameters obtained through symbolic analysis (SA), between older adults with and without hyperuricemia.
Methods: This is a cross-sectional study including 202 community-dwelling old adults, which was clinically stratified as with or without hyperuricemia, according to the cutoff point of serum uric acid ≥ 6 mg/dL for women and ≥ 7 mg/dL for men. Successive RR intervals were recorded along 5 min and analyzed with SA method.
This paper examines how individuals track targets that move in relatively unpredictable trajectories. Gaze and behavioural data were captured as twenty two participants learned a simulated competitive marksmanship task known colloquially as the Death Star over six training days. Participants spontaneously selected one of two consistent target-tracking strategies with approximately equal probability.
View Article and Find Full Text PDFBackground: Increasing perceived hand size with magnifying lenses improves tactile discrimination and induces changes in action performance. We previously demonstrated that motor skills (tested with grip force, finger tapping, and a reach to grasp tasks) improved when actions were performed with magnified compared to normal vision; twenty-eight percent of 25 participants with stroke exhibited significant improvement on a composite measure of motor performance with magnification as compared to a session without magnification.
Methods: To investigate the potential implications of magnification of vision for motor rehabilitation, we recruited individuals with stroke from the original cohort who exhibited an improvement of at least 10% in grip force and/or finger tapping for a home training protocol.
Background: Virtual reality (VR) offers unprecedented opportunity as a scientific tool to study visuomotor interactions, training, and rehabilitation applications. However, it remains unclear if haptic-free hand-object interactions in a virtual environment (VE) may differ from those performed in the physical environment (PE). We therefore sought to establish if the coordination structure between the transport and grasp components remain similar whether a reach-to-grasp movement is performed in PE and VE.
View Article and Find Full Text PDFNeuropsychologia
October 2018
Increasing perceived hand size using magnifying lenses improves tactile discrimination and motor performance in neurologically-intact individuals. We tested whether magnification of the hand can improve motor function in individuals with chronic stroke. Twenty-five individuals with a history of stroke more than 6 months prior to testing underwent a series of tasks exploring different aspects of motor performance (grip force, finger tapping, reaching and grasping, and finger matching) under two visual conditions: magnified or normal vision.
View Article and Find Full Text PDFPurpose: The aims of this study were to compare the autonomic heart control parameters from sarcopenic and non-sarcopenic community-dwelling elders.
Methods: This is a cross-sectional study including 76 community-dwelling old adults, which was clinically stratified as sarcopenic or non-sarcopenic, according to the current recommendations. They were submitted to 5-min recordings of successive RR intervals.
Reaching and grasping movements rely on visual information regarding the target characteristics (e.g. size) and the hand position during the action execution.
View Article and Find Full Text PDFOur understanding of reach-to-grasp movements has evolved from the original formulation of the movement as two semi-independent visuomotor channels to one of interdependence. Despite a number of important contributions involving perturbations of the reach or the grasp, some of the features of the movement, such as the presence or absence of coordination between the digits during the pincer grasp and the extent of spatio-temporal interdependence between the transport and the grasp, are still unclear. In this study, we physically perturbed the index finger into extension during grasping closure on a minority of trials to test whether modifying the movement of one digit would affect the movement of the opposite digit, suggestive of an overarching coordinative process.
View Article and Find Full Text PDFThe analysis of explosive force, through rate of force development (RFD) and contractile impulse (CI), from handgrip strength data seems to be useful and promising information to study the aging of musculoskeletal system and health status. We aimed to test the hypothesis that, in elderly women, the handgrip explosive force could be better associated to the functional mobility than maximum handgrip strength. Handgrip strength and the performance of Timed Up & Go Test (TUG) were measured from sixty-five community-dwelling healthy elderly women.
View Article and Find Full Text PDFReplanning ongoing movements following perturbations requires the accurate and immediate estimation of the motor response based on sensory input. Previous studies have used transcranial magnetic stimulation (TMS) in humans to demonstrate the participation of the anterior intraparietal sulcus (aIPS) and ventral premotor cortex (PMv) in visually mediated state estimation for grasping. Here, we test the role of parietofrontal circuits in processing the corrective responses to haptic perturbations of the finger during prehension.
View Article and Find Full Text PDFJ Undergrad Neurosci Educ
April 2014
Young students struggle with concepts that involve the parallel activity of large numbers of similar entities, precisely the kind of concepts that abound in neuroscience. While a direct experience to laboratory work cannot be replaced, such activities include a steep learning curve and may be impractical in certain course settings. This article describes a set of computer simulations of a number of neural processes using NetLogo (Wilensky, 1999), a software environment for the design and implementation of multi-agent simulations that has an intuitive graphical interface and minimal learning curve.
View Article and Find Full Text PDFThe aging process causes many changes in muscle strength, and analysis of explosive force from handgrip strength seems to be useful and promising in studying the aging musculoskeletal system. Therefore, the purpose of this study was to investigate if explosive force parameters [rate of force development (RFD) and contractile impulse (CI) over the time interval of 0-200 ms from the onset of contraction] during handgrip efforts decline differently than maximum handgrip strength with increasing age. Twenty healthy young women (20-27 years) and 65 healthy elderly women, assigned into three age groups (50-64, 65-74, and 75-86 years), participated in this study.
View Article and Find Full Text PDFWhile the process of hand preshaping during grasping has been studied for over a decade, there is relatively little information regarding the organization of digit contact timing (DCT). This dearth of information may be due to the assumption that DCT while grasping exhibits few regularities or to the difficulty in obtaining information through traditional movement recording techniques. In this study, we employed a novel technique to determine the time of digit contacts with the target object at a high precision rate in normal healthy participants.
View Article and Find Full Text PDFDetermining whether a conflict between gene trees and species trees represents incomplete lineage sorting (ILS) or hybridization involving native and/or invasive species has implications for reconstructing evolutionary relationships and guiding conservation decisions. Among vertebrates, turtles represent an exceptional case for exploring these issues because of the propensity for even distantly related lineages to hybridize. In this study we investigate a group of freshwater turtles (Trachemys) from a part of its range (the Greater Antilles) where it is purported to have undergone reticulation events from both natural and anthropogenic processes.
View Article and Find Full Text PDFParkinson's disease is a degenerative condition whose severity is assessed by clinical observations of motor behaviors. These are performed by a neurological specialist through subjective ratings of a variety of movements including 10-s bouts of repetitive finger-tapping movements. We present here an algorithmic rating of these movements which may be beneficial for uniformly assessing the progression of the disease.
View Article and Find Full Text PDFThe goal of this paper was to investigate the amplitude and sub-100 Hz frequency content of surface electromyography (EMG) signals obtained from agonist, antagonist and synergist muscles during a heel-raise task sustained to failure. Twenty-two healthy adults, 14 men and 8 women participated in the study. Surface EMG data from the raising and lowering phases of the movement were studied in the time (EMG amplitude) and frequency (wavelet transform) domains.
View Article and Find Full Text PDFSeveral studies have found that Parkinson's disease (PD) disrupts the organization of complex motor sequences regardless of the influence of parkinsonian medications. A clear candidate for the neural bases of such deficits, which we term "coordinative," is the failure to integrate propioceptive and visual information by cortico-striatal circuits in a timed fashion. Recent reports, however, have indicated that deep-brain stimulation of the subthalamic nucleus (STN DBS) may result in an improvement in coordinative deficits beyond the amelioration of "intensive deficits" such as bradykinesia and scaling errors.
View Article and Find Full Text PDFInvasive species are classically thought to suffer from reduced within-population genetic variation compared to their native-range sources due to founder effects and population bottlenecks during introduction. Reduction in genetic variation in introduced species may limit population growth, increase the risk of extinction, and constrain adaptation, hindering the successful establishment and spread of an alien species. Results of recent empirical studies, however, show higher than expected genetic variation, rapid evolution, and multiple native-range sources in introduced populations, which challenge the classical scenario of invasive-species genetics.
View Article and Find Full Text PDFPrevious studies in our laboratory examining pointing and reach-to-grasp movements of Parkinson's disease patients (PDPs) have found that PDPs exhibit specific deficits in movement coordination and in the sensorimotor transformations required to accurately guide movements. We have identified a particular difficulty in matching unseen limb position, sensed by proprioception, with a visible target. In the present work, we further explored aspects of complex sensorimotor transformation and motor coordination using a reach-to-grasp task in which object shape, visual feedback, and dopaminergic medication were varied.
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