Motor Signature Research Articles

Multivariate morphological brain signatures predict patients with chronic abdominal pain from healthy control subjects.

Irritable bowel syndrome (IBS) is the most common chronic visceral pain disorder. The pathophysiology of IBS is incompletely understood; however, evidence strongly suggests dysregulation of the brain-gut axis. The aim of this study was to apply multivariate pattern analysis to identify an IBS-related morphometric brain signature that could serve as a central biological marker and provide new mechanistic insights into the pathophysiology of IBS. Parcellation of 165 cortical and subcortical regions was performed using FreeSurfer and the Destrieux and Harvard-Oxford atlases. Volume, mean curvature, surface area, and cortical thickness were calculated for each region. Sparse partial least squares discriminant analysis was applied to develop a diagnostic model using a training set of 160 females (80 healthy controls and 80 patients with IBS). Predictive accuracy was assessed in an age-matched holdout test set of 52 females (26 healthy controls and 26 patients with IBS). A 2-component classification algorithm comprising the morphometry of (1) primary somatosensory and motor regions and (2) multimodal network regions explained 36% of the variance. Overall predictive accuracy of the classification algorithm was 70%. Small effect size associations were observed between the somatosensory and motor signature and nongastrointestinal somatic symptoms. The findings demonstrate that the predictive accuracy of a classification algorithm based solely on regional brain morphometry is not sufficient, but they do provide support for the utility of multivariate pattern analysis for identifying meaningful neurobiological markers in IBS.

Reliability of a novel serious game using dual-task gait profiles to early characterize aMCI

Background: As the population of older adults is growing, the interest in a simple way to detect characterize amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer’s disease (AD), is becoming increasingly important. Serious game (SG) -based cognitive and motor performance profiles while performing everyday activities and dual-task walking (DTW) “motor signatures” are two very promising markers that can be detected in predementia states. We aim to compare the consistency, or conformity, of measurements made by a custom SG with DTW (NAV), a SG without DTW (DOT), neuropsychological measures and genotyping as markers for early detection of aMCI.Methods: The study population included three groups: early AD (n = 86), aMCI (n = 65), and healthy control subjects (n = 76), who completed the custom SG tasks in three separate sessions over a 3-month period. Outcome measures were neuropsychological data across-domain and within-domain intra-individual variability (IIV) and DOT and NAV latency-based and accuracy-based IIV. IIV reflects a transient, within-person change in behavioral performance, either during different cognitive domains (across-domain) or within the same domain (within-domain). Test–retest reliability of the DOT and NAV markers were assessed using an intraclass correlation (ICC) analysis.Results: Results indicated that performance data, such as the NAV latency-based and accuracy-based IIV, during the task displayed greater reliability across sessions compared to DOT. During the NAV task-engagement, the executive function, planning, and motor performance profiles exhibited moderate to good reliability (ICC = 0.6–0.8), while during DOT, executive function and spatial memory accuracy profiles exhibited fair to moderate reliability (ICC = 0.3–0.6). Additionally, reliability across tasks was more stable when three sessions were used in the ICC calculation relative to two sessions.Discussion: Our findings suggest that “motor signature” data during the NAV tasks were a more reliable marker for early diagnosis of aMCI than DOT. This result accentuates the importance of utilizing motor performance data as a metric for aMCI populations where memory decline is often the behavioral outcome of interest. In conclusion, custom SG with DTW performance data provide an ecological and reliable approach for cognitive assessment across multiple sessions and thus can be used as a useful tool for tracking longitudinal change in observational and interventional studies on aMCI.

Social Motor Coordination in Schizophrenia Patients: From Impairment to Rehabilitation

Introduction Motor coordination of interacting people influences social cognitive functioning, impacting feelings of connectedness or interpersonal rapport and communication. Social interaction deficits are one of the most significant and defining features of schizophrenia but until recently no quantitative and objective measures of social motor coordination in schizophrenia have been proposed. Objectives We aimed to investigate social motor coordination of patients suffering from schizophrenia and the implication of this paradigm in rehabilitation, using priming effects. Methods Interpersonal coordination was assessed with a hand-held pendulum task. In the first experiment we evaluated intentional social motor coordination in 20 schizophrenia patients and 20 healthy controls. In the second experiment, hand-held pendulum task was realized after implicit exposure to pro-social, non-social or anti-social primes, in 45 patients and 45 healthy controls. Results We found that intentional social motor coordination was impaired in patient suffering from schizophrenia with lower stability and the fact that patients never led the coordination. In the second experiment, we found that schizophrenia patients who received pro-social priming have greater stability during interpersonal coordination. Furthermore, pro-social priming induced, in their synchronization partner greater feelings of connectedness towards patients. Conclusion First we demonstrate that schizophrenic patients have a specific relational motor signature. Such findings may lead to the development of rehabilitation protocols improving social motor coordination and successful social exchanges of patients. This hypothesis is strengthened by the fact that pro-social priming can have a direct and important effect on improving social motor interaction in patients suffering from schizophrenia.

Use of Machine Learning to Identify Children with Autism and Their Motor Abnormalities.

In the present work, we have undertaken a proof-of-concept study to determine whether a simple upper-limb movement could be useful to accurately classify low-functioning children with autism spectrum disorder (ASD) aged 2-4. To answer this question, we developed a supervised machine-learning method to correctly discriminate 15 preschool children with ASD from 15 typically developing children by means of kinematic analysis of a simple reach-to-drop task. Our method reached a maximum classification accuracy of 96.7% with seven features related to the goal-oriented part of the movement. These preliminary findings offer insight into a possible motor signature of ASD that may be potentially useful in identifying a well-defined subset of patients, reducing the clinical heterogeneity within the broad behavioral phenotype.

The motor signature of mild cognitive impairment: results from the gait and brain study.

Background.Early motor changes associated with aging predict cognitive decline, which suggests that a “motor signature” can be detected in predementia states. In line with previous research, we aim to demonstrate that individuals with mild cognitive impairment (MCI) have a distinct motor signature, and specifically, that dual-task gait can be a tool to distinguish amnestic (a-MCI) from nonamnestic MCI.Methods.Older adults with MCI and controls from the “Gait and Brain Study” were assessed with neurocognitive tests to assess cognitive performance and with an electronic gait mat to record temporal and spatial gait parameters. Mean gait velocity and stride time variability were evaluated under simple and three separate dual-task conditions. The relationship between cognitive groups (a-MCI vs nonamnestic MCI) and gait parameters was evaluated with linear regression models and adjusted for confounders.Results.Ninety-nine older participants, 64 MCI (mean age 76.3±7.1 years; 50% female), and 35 controls (mean age 70.4±3.9 years; 82.9% female) were included. Forty-two participants were a-MCI and 22 were nonamnestic MCI. Multivariable linear regression (adjusted for age, sex, physical activity level, comorbidities, and executive function) showed that a-MCI was significantly associated with slower gait and higher dual-task cost under dual-task conditions.Conclusion.Participants with a-MCI, specifically with episodic memory impairment, had poor gait performance, particularly under dual tasking. Our findings suggest that dual-task assessment can help to differentiate MCI subtyping, revealing a motor signature in MCI.

Localizing the source of mouse ultrasonic vocalizations using a four-channel microphone array.

Event Abstract Back to Event Localizing the source of mouse ultrasonic vocalizations using a four-channel microphone array. Joshua P. Neunuebel1*, Adam L. Taylor2 and Roian S. Egnor1 1 Howard Hughes Medical Institute - Janelia Farm Research Campus, United States 2 Howard Hughes Medical Institute - Janelia Farm Research Campus, United States Mice emit ultrasonic vocalizations that are characterized by frequencies ranging from 30 to 125 kHz, which exceed the thresholds of human hearing. These vocalizations may facilitate communication (Barthelemy et al., 2004), indicate social status (Pomerantz et al., 1983), aid in mate selection (Hammerschmidt et al., 2009), and help identify individuals (Sugimoto et al., 2011). Unlike birds, elephants, marmosets, and other animals that vocalize in a range that is audible to humans, identifying the source of a mouse ultrasonic vocalization during a social interaction with multiple potential vocalizers is problematic because mice lack a visible motor signature during vocal output and the vocalizations are inaudible. Accurately identifying the source of the sound is essential for understanding the functional role of mouse ultrasonic vocalization during social behavior. To address this issue, we constructed a microphone array with four microphones, each capable of recording up to 200 kHz (Avisoft; CM16/CMPA), located in a large, acoustically favorable mouse cage. For each vocalization, the delays in the arrival time between each pair of microphones were calculated for all pairwise microphone combinations and used to determine the location of the sound. To test the capacities of the system, two sets of experiments were conducted. First, a set of 25 prerecorded mouse vocalizations, obtained by pairing two SWR mice of the opposite gender and ranging from 20 to 115 ms in duration, were played and repeated five times from a single speaker (Avisoft; Ultrasonic Electrostatic Speaker ESS16). The speaker was shifted with five coarse movements covering the entire mouse cage or shifted with multiple fine movements in a smaller, centrally confined region of the cage. A second set of experiments consisted of recording vocalizations from a single freely moving SWR mouse that were elicited by either urine or bedding of female SWR mice. This method provides a powerful tool to address the function of mouse ultrasonic vocalizations in social settings. References Barthelemy M, Gourbal BE, Gabrion C, & Petit G. (2004). “Influence of the female sexual cycle on BALB/c mouse calling behaviour during mating.” Naturwissenschaften 91(3):135-8. Pomerantz SM, Nunez AA, & Bean NJ. (1983). "Female behavior is affected by male ultrasonic vocalizations in house mice." Physiology & Behavior 31: 91-96. Hammerschmidt K, Radyushkin K, Ehrenreich H, & Fischer J. (2009). “Female mice respond to male ultrasonic 'songs' with approach behaviour.” Biol Lett 5(5):589-92. Sugimoto H, Okabe S, Kato M, Koshida N, Shiroishi T, Mogi K, Kikusui T, & Koide T. (2011). “A role for strain differences in waveforms of ultrasonic vocalizations during male-female interaction.” PLoS One 6(7): e22093. Keywords: Animal trajectories, auditory, Communication, Positional tracking, Social context, Sound, Sound source localization, ultrasound Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for participant symposium and student poster award) Topic: Social Behavior Citation: Neunuebel JP, Taylor AL and Egnor RS (2012). Localizing the source of mouse ultrasonic vocalizations using a four-channel microphone array.. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00326 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: 30 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Joshua P Neunuebel, Howard Hughes Medical Institute - Janelia Farm Research Campus, Ashburn, VA, 20147, United States, neunuebelj@janelia.hhmi.org 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 Joshua P Neunuebel Adam L Taylor Roian S Egnor Google Joshua P Neunuebel Adam L Taylor Roian S Egnor Google Scholar Joshua P Neunuebel Adam L Taylor Roian S Egnor PubMed Joshua P Neunuebel Adam L Taylor Roian S Egnor 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.

A motor signature of REM sleep behavior disorder

The purpose of this study was to determine if there was a common pattern in movements during REM sleep behavior disorder (RBD). We blindly compared video-monitored movements during RBD (n = 136 clips) and wakefulness/arousal (n = 53 clips) in patients with Parkinson's disease (n = 29) and without parkinsonism (idiopathic RBD, n = 31; narcolepsy, n = 5). The scorers accurately guessed the sleep/wake stage of 94% of video clips. Compared with wake movements, RBD movements were faster and more often repeated, jerky, and pseudohallucinatory, not self-centered, never associated with tremor, and rarely involved the environment in an appropriate manner. A specific posture of the hand (limp wrist with flexed digits) during grasping movements was evidenced during RBD in 48% of patients, reminiscent of hand-babbling in babies. These characteristics of movements were found in the 3 conditions (Parkinson's disease, idiopathic RBD, and primary narcolepsy), delineating a common motor signature of RBD.

Sprinter’s motor signature does not change with fatigue

The aim of this study was to investigate human adaptations to fatigue induced by track sprint repetitions. Eight male sprinters were asked to run 4×100m as quickly as possible with 3min of recovery. Subjects were filmed (50Hz) in order to measure stride length and frequency. Velocity was measured by means of radar (250Hz) while contact and flight times were registered wirelessly by two pressure sensors (400Hz) embedded under the insole of the subjects' shoes. Contact and flight times were used to calculate stiffness. In addition, blood samples were taken prior to warm-up, 1min after each 100-m sprint and every 2min after the last repetition until a lactate peak ([BLa]) was reached. [BLa] did not affect mechanical and stride parameters. Inter-series ANOVA showed that velocity decreased significantly (-3.55%) between Repetition 1 (8.18±0.29ms(-1)) and Repetition 4 (7.89±0.42ms(-1)), while [BLa] increased from 6.74±1.15 to 13.58±1.48mmoll(-1) (p<0.05). The first main result was that leg stiffness remained constant until Repetition 3 and then dramatically increased at Repetition 4, whereas vertical stiffness remained constant throughout all four repetitions. This behavior could be considered to be a neuromuscular adaptation to fatigue used by skilled athletes. The second main result was that velocity decreased during the second phase (30-80m) of the entire 100m. In addition, a PCA revealed three different sprint profiles explaining 88.2% of the total variance: the contact-time-pattern (39.46%), force-pattern (27.96%) and stride-pattern (20.77%). Two different motor signatures were identified with fatigue. In the first, athletes switch from the key variable to another when exhausted without changing their motor behavior (during Repetition 3 and/or Repetition 4). In the second, athletes do not change their motor behavior with fatigue.

Detection of Motor Bearing Outer Raceway Defect by Wavelet Packet Transformed Motor Current Signature Analysis

Motor current signature analysis (MCSA) is a method of sampling the running current through a data logger at high sampling speed, followed by using mathematical tools such as fast Fourier transform (FFT) to identify relevant motor signature changes in the frequency spectrum for motor fault identification. Although there are numerous types of motor fault, research conducted by Electric Power Research Institute (EPRI) indicated that motor bearing fault accounted for more than 40% of all types of motor fault. The main aim of this paper is to evaluate the use of MCSA for detecting bearing outer raceway defect. Stage-by-stage experimental verification shows that the method of MCSA is effective in detecting bearing fault with the use of wavelet packet transformation (WPT). In addition, a novel linear application of linear regression for wavelet data analysis is applied and presented in this paper.

Online and Remote Motor Energy Monitoring and Fault Diagnostics Using Wireless Sensor Networks

This paper identifies the synergies between wireless sensor networks (WSNs) and nonintrusive electrical-signal-based motor signature analysis and proposes a scheme of applying WSNs in online and remote energy monitoring and fault diagnostics for industrial motor systems. The main scope is to provide a system overview where the nonintrusive nature of the electrical-signal-based motor signature analysis enables its applications in a WSN architecture. Special considerations in designing nonintrusive motor energy monitoring and fault diagnostic methods in such systems are discussed. This paper also provides detailed analyses to address the real-world challenges in designing and deploying WSNs in practice, including wireless-link-quality dynamics, noise and interference, and environmental impact on communication range and reliability. The overall system feasibility is investigated through a series of laboratory experiments and field tests. First, the concept of a remote and online energy monitoring and fault diagnostic system is demonstrated using a simplified star-type IEEE 802.15.4 compliant WSN in the laboratory. Two well-established nonintrusive motor diagnostic algorithms are intentionally used to prove the feasibility. Next, the challenges of applying the proposed WSN scheme in real industrial environments are analyzed experimentally using field test results.

Prestin's Anion Transport and Voltage-Sensing Capabilities Are Independent

The integral membrane protein prestin, a member of the SLC26 anion transporter family, is responsible for the voltage-driven electromotility of mammalian outer hair cells. It was argued that the evolution of prestin's motor function required a loss of the protein's transport capabilities. Instead, it was proposed that prestin manages only an abortive hemicycle that results in the trapped anion acting as a voltage sensor, to generate the motor's signature gating charge movement or nonlinear capacitance. We demonstrate, using classical radioactive anion ([14C]formate and [14C]oxalate) uptake studies, that in contrast to previous observations, prestin is able to transport anions. The prestin-dependent uptake of both these anions was twofold that of cells transfected with vector alone, and comparable to SLC26a6, prestin's closest phylogenetic relative. Furthermore, we identify a potential chloride-binding site in which the mutations of two residues (P328A and L326A) preserve nonlinear capacitance, yet negate anion transport. Finally, we distinguish 12 charged residues out of 22, residing within prestin's transmembrane regions, that contribute to unitary charge movement, i.e., voltage sensing. These data redefine our mechanistic concept of prestin.

Acute Superior Oblique Palsy in Monkeys: I. Changes in Static Eye Alignment

To investigate immediate and long-term changes in static ocular alignment with acute acquired superior oblique palsy (SOP) in monkeys. The trochlear nerve was severed intracranially in two rhesus monkeys. After the surgery, the paretic eye was patched for 6 to 9 days, and then binocular viewing was allowed. Three-axis eye movements (horizontal, vertical, and torsional) were measured with binocular, dual search coils. Eye movements were recorded over a +/-20 degrees horizontal and vertical range of fixations before the lesion and then, beginning the first day after surgery. Changes in alignment with +/-30 degrees head tilt were also studied. The main findings were (1) misalignment (10-12 degrees vertical in adduction, down; 10-12 degrees torsional in abduction, down); (2) changes in vertical deviation (VD) with head tilt (Delta 2-6 degrees with left versus right 30 degrees tilt); and (3) changes in comitance and VD over time. During the early postlesion period, before binocular viewing was allowed, VD decreased and comitance improved. Once binocular viewing was allowed, VD increased and comitance worsened. Rhesus monkeys with induced SOP show a characteristic pattern of misalignment that helps define the ocular motor signature of acute denervation of the superior oblique muscle. The animals also showed striking changes over time in the amount and comitance of the vertical misalignment that depended on whether viewing was monocular or binocular, suggesting a role for proprioception in adaptation to misalignment with habitual monocular viewing.

Unintended interpersonal co-ordination: “can we march to the beat of our own drum?”

The main purpose of this article was to identify whether an interpersonal motor co-ordination emerges between two participants when they intentionally tried to not co-ordinate their movements between each other. To do this we conjointly examined both the emergence of the motor co-ordination (collective properties) between the two participants, and the maintenance of the individual intrinsic motor properties present in the interpersonal co-ordination. Six pairs of participants performed three situations where they freely moved their right forearm with no instructions (nor restrictions) on frequency or relative phase. The goal of the first two situations was for participants to intentionally co-ordinate ( P-on) or not co-ordinate ( P-off) their movements between each other. In order to determine his/her individual motor properties, each participant performed this task alone, in a third condition. The cross-wavelet transform (CWT) revealed in the P-off condition the emergence of an unintended co-ordination in the frequency domain. Moreover, random distribution of the relative phase appeared, in this condition, whereas in the P-on condition, we observed a collective organization especially at a relative phase around 0°. Conjointly, the wavelet transform (WT) showed the presence of individual intrinsic motor properties (motor signature) in the three conditions. These results indicate that, when there was information sharing, participants could not avoid (unintentionally) coordinating with someone. This study suggests that, in daily life, interactions with other people lead the individual motor behavior to adapt unintended motor co-ordination.

Motor Signature, Falls Risk, and Home-Based Interventions in Older Adults With Mild Cognitive Impairment

Motor Signature, Falls Risk, and Home-Based Interventions in Older Adults With Mild Cognitive Impairment

A review of induction motors signature analysis as a medium for faults detection

This paper is intended as a tutorial overview of induction motors signature analysis as a medium for fault detection. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of motor signature analysis for the detection and the localization of abnormal electrical and mechanical conditions that indicate, or may lead to, a failure of induction motors. The paper is focused on the so-called motor current signature analysis which utilizes the results of spectral analysis of the stator current. The paper is purposefully written without state-of-the-art terminology for the benefit of practising engineers in facilities today who may not be familiar with signal processing.

Instantaneous power as a medium for the signature analysis of induction motors

Preventive maintenance of electric drive systems with induction motors involves monitoring of their operation for detection of abnormal electrical and mechanical conditions that indicate, or may lead to, a failure of the system. Intensive research effort has been for sometime focused on the motor current signature analysis (MCSA). The MCSA techniques utilize the results of spectral analysis of the stator current. Reliable interpretation of the spectra is difficult, since distortions of the current waveform caused by the abnormalities in the drive system are usually minute. In this paper, an alternate medium for the motor signature analysis, namely the instantaneous power, is proposed. By theoretical analysis, computer simulations, and laboratory experiments, it is shown that the instantaneous power carries more information than the current itself. Utilization of the instantaneous power is thus enhancing the reliability of diagnostics of induction motor drives.

Noninvasive detection of broken rotor bars in operating induction motors

A description is given of a computer-based noninvasive broken bar fault detector for squirrel-cage rotors of induction motors. The detector can be applied to existing motors without disassembly or shutdown and has the sensitivity to diagnose the presence of a single broken bar or an open end ring. It is suitable for monitoring the trend of the motor signature, or it can be used as a one-time diagnostic tool.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>