Motion Sensitivity Research Articles

Perspective Cues Make Eye-specific Contributions to 3-D Motion Perception.

Robust 3-D visual perception is achieved by integrating stereoscopic and perspective cues. The canonical model describing the integration of these cues assumes that perspective signals sensed by the left and right eyes are indiscriminately pooled into a single representation that contributes to perception. Here, we show that this model fails to account for 3-D motion perception. We measured the sensitivity of male macaque monkeys to 3-D motion signaled by left-eye perspective cues, right-eye perspective cues, stereoscopic cues, and all three cues combined. The monkeys exhibited idiosyncratic differences in their biases and sensitivities for each cue, including left- and right-eye perspective cues, suggesting that the signals undergo at least partially separate neural processing. Importantly, sensitivity to combined cue stimuli was greater than predicted by the canonical model, which previous studies found to account for the perception of 3-D orientation in both humans and monkeys. Instead, 3-D motion sensitivity was best explained by a model in which stereoscopic cues were integrated with left- and right-eye perspective cues whose representations were at least partially independent. These results indicate that the integration of perspective and stereoscopic cues is a shared computational strategy across 3-D processing domains. However, they also reveal a fundamental difference in how left- and right-eye perspective signals are represented for 3-D orientation versus motion perception. This difference results in more effective use of available sensory information in the processing of 3-D motion than orientation and may reflect the temporal urgency of avoiding and intercepting moving objects.

Vestibular-autonomic interactions: beyond orthostatic dizziness.

This review aims to summarize the current literature describing vestibular-autonomic interactions and to describe their putative role in various disorders' clinical presentations, including orthostatic dizziness and motion sensitivity. The vestibular-autonomic reflexes have long been described as they relate to cardiovascular and respiratory function. Although orthostatic dizziness may be in part related to impaired vestibulo-sympathetic reflex (orthostatic hypotension), there are various conditions that may present similarly. A recent clinical classification aims to improve identification of individuals with hemodynamic orthostatic dizziness so that appropriate recommendations and management can be efficiently addressed. Researchers continue to improve understanding of the underlying vestibular-autonomic reflexes with recent studies noting the insular cortex as a cortical site for vestibular sensation and autonomic integration and modulation. Work has further expanded our understanding of the clinical presentation of abnormal vestibular-autonomic interactions that may occur in various conditions, such as aging, peripheral vestibular hypofunction, traumatic brain injury, and motion sensitivity. The vestibular-autonomic reflexes affect various sympathetic and parasympathetic functions. Understanding these relationships will provide improved identification of underlying etiology and drive improved patient management.

Dorsal and Ventral Stream Function in Children With Developmental Coordination Disorder.

Dorsal stream cortical networks underpin a cluster of visuomotor, visuospatial, and visual attention functions. Sensitivity to global coherence of motion and static form is considered a signature of visual cortical processing in the dorsal stream (motion) relative to the ventral stream (form). Poorer sensitivity to global motion compared to global static form has been found across a diverse range of neurodevelopmental disorders, suggesting a “dorsal stream vulnerability.” However, previous studies of global coherence sensitivity in Developmental Coordination Disorder (DCD) have shown conflicting findings. We examined two groups totalling 102 children with DCD (age 5–12 years), using the “Ball in the Grass” psychophysical test to compare sensitivity to global motion and global static form. Motor impairment was measured using the Movement-ABC (M-ABC). Global coherence sensitivity was compared with a typically developing control group (N = 69) in the same age range. Children with DCD showed impaired sensitivity to global motion (p = 0.002), but not global form (p = 0.695), compared to controls. Within the DCD group, motor impairment showed a significant linear relationship with global form sensitivity (p < 0.001). There was also a significant quadratic relationship between motor impairment and global motion sensitivity (p = 0.046), where poorer global motion sensitivity was only apparent with greater motor impairment. We suggest that two distinct visually related components, associated with global form and global motion sensitivity, contribute to DCD differentially over the range of severity of the disorder. Possible neural circuitry underlying these relationships is discussed.

Bifurcation analysis of dual-sidestay landing gear locking performance considering joint clearance

Sidestay lock mechanism is an important part of landing gear system, and the locking performance can be analyzed based on changes in its stability. However, during numerical continuation analysis of fully-rigid dual-sidestay landing gear without clearance, it has been found that the appearance of bifurcation points does not necessarily imply that both sidestay links can be locked synchronously. This problem reveals the limitations of fully-rigid model with ideally-articulated in solving dual-sidestay mechanisms with extremely high motion sensitivity. Therefore, this study proposes a bifurcation analysis method for synchronous locking of dual-sidestay landing gears, which takes into consideration the joint clearance. For in-depth analysis of this problem, we initially build kinematic and mechanical models of a landing gear mechanism that consider joint clearance. Then, the models are solved based on continuation. The fundamental causes of synchronous locking are discussed in detail, and the number of bifurcation points is found to be closely related to whether the landing gear is completely locked. Finally, the effects of structural parameters on the synchronous locking are analyzed, and the feasible region of parameters satisfying synchronous locking condition is given, which agrees well with the test results.

Materials Selection Principles for Sensing Human Motion and Physiological Signals Via Textiles

The advancement of smart apparels capable of tracking human physiological signals and body locomotion have a great potential to revolutionize human performance sensing and personalized health monitoring through transforming daily life clothing into sensors. Quantitative evaluation of kinetic parameters of individual gait along with physiological signals can be employed in games and sports, as well as in diagnosis of many diseases such as Parkinson’s, Multiple Sclerosis, and sleep disorders. Among different methodologies in developing wearable sensors such as inertial measurement units, textile-based electromechanical sensors encompass the majority of widely adopted applications. Electromechanical sensors fall into three major categories based on their active mechanisms: piezoelectric sensors, triboelectric sensors, and piezoresistive sensors. Recently, different combination of materials and designs have been reported to develop wearable sensors, each of which provides a unique window into a slightly different range of motion sensitivity. For example, some human signals and motions lie in the small-scale range of pressures such as those of a subtle touch, arterial pulses, and sound vibrations, while the other body movements lie in medium to large range of pressures, such as joint movements, and locomotion during sleep and intense activities. The ability to design an unobtrusive wearable sensor being highly responsive in the required range of signals calls for getting an insight into the difference between the three mechanisms of electromechanical sensing and their corresponding responses under certain conditions.Here, we introduced a set of materials selection principles which gives researchers an in-depth insight into how to design a wearable electromechanical sensor when it comes to acquire data from a specific source of motion. In order to achieve this goal, we performed a set of purposefully designed experiments on three types of wash-stable fabric-based electromechanical sensors that had already been introduced by our lab, i.e., triboelectric sensor, piezoelectric sensor, and piezoionic sensor as a subset of piezoresistive ones. These experiments explored the effect of impact pressure, bending angle and speed, frequency, presence of a base pressure, response time, breathability, and having a multi-layer structure on the performance and sensitivity of each type of sensors. For an instance, it turned out that the triboelectric and piezoelectric sensors are a more reliable sensing element for dynamic pressures, such as joint movements, with the former being failed in the presence of a base pressure. Piezoresistive sensors are the one with the ability to sense both static and dynamic pressures, as well as being responsive under a base pressure. However, piezoresistive one would not be a choice when it comes to bending applications. Upon this comprehensive comparison, we demonstrated a conclusive map which can provide the researchers with distinguishing features of these three types of sensors to be used in corresponding niche applications.For example, some human signals and motions lie in the small-scale range of pressures such as those of a subtle touch, arterial pulses, and sound vibrations, while the other body movements lie in medium to large range of pressures, such as joint movements, and locomotion during sleep and intense activities. The ability to design an unobtrusive wearable sensor being highly responsive in the required range of signals calls for getting an insight into the difference between the three mechanisms of electromechanical sensing and their corresponding responses under certain conditions. Figure 1

Surface motion of an arbitrary number of semi-circular viscoelastic alluvial valleys for incident planeSHwaves

SUMMARYA semi-analytical treatment of the seismic response of an arbitrary number of semi-circular viscoelastic alluvial valleys (including an infinite number of periodically distributed ones) in an elastic half-space under obliquely incident plane SH waves is presented. In terms of a radial wave function expansion and a region matching approach, a rigorous solution is derived for general computation for the anti-plane shear wave scattering problem. Upon confirmation of its accuracy with past solutions for single and twin elastic alluvial valleys, the proposed solution is used to present a comprehensive set of numerical examples to illustrate the sensitivity of the ground motion to the size, distribution, modulus, damping, and number of multiple alluvial valleys and frequency and direction of incident waves. It is found that the magnitudes of ground motions of a central alluvial valley are intensified and reduced by the surrounding valleys for vertical and grazing wave incidences, respectively. In addition, the duration of ground motions of the central alluvial valley tends to be prolonged due to the incoming secondary waves generated by surrounding valleys.

Reduced vestibular perception thresholds in persistent postural-perceptual dizziness- a cross-sectional study

BackgroundPersistent postural-perceptual dizziness (PPPD) is the most common functional vestibular disorder. A multisensory mismatch altered by psychological influences is considered to be an important pathophysiological mechanism. Increased cortical and subcortical excitability may play a role in the pathophysiology of PPPD. We hypothesized that decreased motion perception thresholds reflect one mechanism of the abnormal vestibular responsiveness in this disorder. We investigated the vestibular perception thresholds and the vestibular ocular reflex with a rotatory chair experiment to gain insights in the processing and adaption to vestibular provocation.MethodsIn this cross-sectional study 26 female PPPD patients and 33 healthy female age matched controls (HC) were investigated sitting in a motorized rotary chair shielded regarding visual and acoustic stimuli. The chair was rotated for 20 minutes with slowly increasing velocity to a maximum of 72°/s. We functionally tested motion perception thresholds and vegetative responses to rotation as well as vestibular-ocular reflex thresholds. We additionally investigated several psychological comorbidities (i.e. depression, anxiety, somatosensory amplification) using validated scores. Conventional dizziness scores were obtained to quantify the experienced dizziness and impact on daily life.ResultsPPPD patients showed a significant reduced vestibulo-perceptual threshold (PPPD: 10.9°/s vs. HC: 29.5°/s; p<0.001) with increased motion sensitivity and concomitant vegetative response during and after the chair rotation compared to healthy controls. The extent of increased vestibular sensitivity was in correlation with the duration of the disease (p=0.043). No significant difference was measured regarding nystagmus parameters between both groups.ConclusionPPPD patients showed increased vegetative response as well as decreased vestibulo-perceptual thresholds which are related to disease duration. This is of interest as PPPD might be sustained by increased vestibular excitability leading to motion intolerance and induction of dizziness when exposed to movement.

Effect of Yogasanas Versus Gaze Stability and Habituation Exercises on Dizziness in Vestibular Dysfunction.

Dizziness is a typical manifestation of vestibular pathologies. Clinical studies have shown that it affects 1.82% of young adults to more than 30% older adults. Habituation and compensation are some traditional rehabilitation protocols. Yoga is also known to have a significant effect on vestibulopathy. Hence, a need arises to compare the above two maneuvers. Participants were recruited (n = 32) after screening using the Dix-Hallpike and head impulse test. They were then divided into two groups (n = 16). The first one, Group A, received yogasanas, and the second one, Group B, received gaze stabilization and habituation exercises for 4 days a week for 3 weeks. Pre- and post intervention outcome measures were taken using the motion sensitivity quotient (MSQ) score and Dizziness Handicap Inventory (DHI) scale. In reducing symptoms of dizziness, the between-group comparison shows that Group A has shown greater improvement (12.37% ±1.43%) in MSQ and Group B has shown greater improvement (16.12 ± 3.56) in DHI. Within-group comparison shows that both the interventions are effective in reducing symptoms of dizziness (P < 0.05). Both gaze stabilization along with habituation exercises and yogasanas are effective in improving the symptoms of dizziness in patients with peripheral vestibular dysfunction. When compared between the groups, yogasanas had a superior hand in the MSQ score, whereas gaze stabilization and habituation exercises had a superior hand in the DHI scale.

A-95 The Relationship between Attention Deficit Hyperactivity Disorder (ADHD) and Vestibular Impairments Following Adolescent Sports-Related Concussion (SRC)

Abstract Objective Athletes with ADHD may experience longer and/or more complicated recoveries following SRC; however, previous research has focused on neurocognitive outcomes. The objective of this study was to investigate the relationship between a history of ADHD among adolescent athletes and vestibular impairments following SRC. Method Participants included 166 athletes aged 15.9 +/− 1.5 who sustained an SRC, including 25 with a documented history of ADHD. Appropriate summary statistics were used to describe the data. ADHD and non-ADHD groups were compared using t-tests and Mann–Whitney U tests for continuous variables and Chi-square tests for categorical variables. A linear regression model analyzed the relationship between a history of ADHD and vestibular outcomes including horizontal and vertical vestibulo-ocular reflex (hVOR; vVOR), visual motion sensitivity (VMS), and Dizziness Handicap Index (DHI), while referral to vestibular therapy (VT) was analyzed using logistic regression. Results Athletes with ADHD experienced significantly higher rates of on-field dizziness, (p = 0.039) and dizziness following vVOR testing on the Vestibular/Ocular Motor Screening (VOMS; p = 0.041). Athletes with ADHD were more likely to be referred to vestibular therapy (VT) (p = 0.033) and displayed abnormal vVOR test during the initial VT visit (p = 0.040). Conclusions Adolescent athletes with a history of ADHD are more likely to report on-field dizziness following SRC and increased dizziness with vVOR testing on VOMS, thus resulting in more frequent referrals to VT, where they also display abnormal vVOR results. Additional research is needed to improve treatment strategies and recovery outcomes in athletes after SRC.

A Randomized Controlled Trial of Precision Vestibular Rehabilitation in Adolescents following Concussion: Preliminary Findings

To compare the effectiveness of a 4-week precision vestibular rehabilitation intervention compared with a behavioral management control intervention for adolescents with vestibular symptoms/impairment within 21days of a concussion. This study used double-blind, randomized controlled trial design involving adolescent (12-18 years) patients with a diagnosed sport/recreation-related concussion with vestibular symptoms/impairment from a concussion-specialty clinic between October 2018 and February 2020. Eligible participants were randomized in a 1:1 to either a 4-week vestibular intervention group (VESTIB) or a behavioral management control group (CONTROL). CONTROLS (n=25) were prescribed behavioral management strategies (eg, physical activity, sleep, hydration, nutrition, stress management) and instructed to perform stretching/physical activity (eg, walking, stationary cycle) 30minutes/day. VESTIB (n=25) were prescribed precision vestibular rehabilitation exercises and instructed to perform at-home exercises for 30minutes/day. Primary outcomes were improvement in Vestibular/Ocular Motor Screening vestibular items (ie, horizontal/vertical vestibular-ocular reflex, visual motion sensitivity) at 4weeks postenrollment. We screened 310 and enrolled a total of 55 (18%) adolescent patients who were randomized to one of the interventions. Fifty of fifty-five (91%) participants completed all aspects of the study protocol. Participants in VESTIB improved significantly across the intervention period in horizontal (mean difference-1.628; 95% CI [-3.20, -0.06]; P=.04) and vertical (mean difference-2.24; 95% CI [-4.01, -0.48]; P=.01) vestibular-ocular reflex, but not visual motion sensitivity (mean difference-2.03; 95% CI [-4.26, 0.19]) of the Vestibular/Ocular Motor Screening score compared with CONTROLS. Overall, the vestibular intervention group experienced greater clinical improvements in vestibular symptoms/impairment than controls across the 4-week intervention. ClinicalTrials.gov: NCT03555370.

Migraine Features in Patients With Isolated Aural Fullness and Proposal for a New Diagnosis.

To compare the presence of migraine features between patients with isolated aural fullness (AF) who meet the diagnostic criteria for migraine headache and those who do not, and to propose diagnostic criteria for migraine-related AF based on our results. We performed a retrospective study of patients presenting to a tertiary-care neurotology clinic between 2014 and 2020 with migraine-related AF. This was defined as isolated, prolonged aural fullness concurrent with migraine features once other etiologies were ruled out via examination, audiometry, and imaging. Migraine features were compared between patients meeting the diagnostic criteria for migraine headache and those not meeting the criteria. Seventy-seven patients with migraine-related AF were included. The mean age was 56 ± 15 years and 55 (71%) patients were female. Eleven (14%) patients fulfilled the criteria for migraine headache (migraine group). Of the 66 patients who did not meet the criteria (nonmigraine group), 17 (26%) met 4/5 criteria, and 32 (48%) met 3/5 criteria, for a total of 49 (74%) patients. The migraine and nonmigraine groups were only different in 5 of 20 features, including family history of migraine (p = 0.007), sound sensitivity (p < 0.001), mental fogginess (p = 0.008), visual motion sensitivity (p = 0.008), and light sensitivity (p < 0.001). There are minimal differences in the overall prevalence of migraine features between patients with migraine-related AF who meet and do not meet the diagnostic criteria for migraine. Our findings suggest that the criteria may be too stringent and exclude many patients from potentially benefitting from treatment with migraine prophylaxis.

Abdominal T2-Weighted Imaging and T2 Mapping Using a Variable Flip Angle Radial Turbo Spin-Echo Technique.

T2 mapping is of great interest in abdominal imaging but current methods are limited by low resolution, slice coverage, motion sensitivity, or lengthy acquisitions. Develop a radial turbo spin-echo technique with refocusing variable flip angles (RADTSE-VFA) for high spatiotemporal T2 mapping and efficient slice coverage within a breath-hold and compare to the constant flip angle counterpart (RADTSE-CFA). Prospective technical efficacy. Testing performed on agarose phantoms and 12 patients. Focal liver lesion classification tested on malignant (N=24) and benign (N=11) lesions. 1.5 T/RADTSE-VFA, RADTSE-CFA. A constrained objective function was used to optimize the refocusing flip angles. Phantom and/or in vivo data were used to assess relative contrast, T2 estimation, specific absorption rate (SAR), and focal liver lesion classification. STATISTICAL TESTS: t-Tests or Mann-Whitney Rank Sum tests were used. Phantom data did not show significant differences in mean relative contrast (P=0.10) and T2 accuracy (P=0.99) between RADTSE-VFA and RADTSE-CFA. Adding noise caused T2 overestimation predominantly for RADTSE-CFA and low T2 values. In vivo results did not show significant differences in mean spleen-to-liver (P=0.62) and kidney-to-liver (P=0.49) relative contrast between RADTSE-VFA and RADTSE-CFA. Mean T2 values were not significantly different between the two techniques for spleen (T2VFA =109.2 ± 12.3msec; T2CFA =110.7 ± 11.1msec; P=0.78) and kidney-medulla (T2VFA =113.0 ± 8.7msec; T2CFA =114.0 ± 8.6msec; P=0.79). Liver T2 was significantly higher for RADTSE-CFA (T2VFA =52.6 ± 6.6msec; T2CFA =60.4 ± 8.0msec) consistent with T2 overestimation in the phantom study. Focal liver lesion classification had comparable T2 distributions for RADTSE-VFA and RADTSE-CFA for malignancies (P=1.0) and benign lesions (P=0.39). RADTSE-VFA had significantly lower SAR than RADTSE-CFA increasing slice coverage by 1.5. RADTSE-VFA provided noise-robust T2 estimation compared to the constant flip angle counterpart while generating T2-weighted images with comparable contrast. The VFA scheme minimized SAR improving slice efficiency for breath-hold imaging. 2 TECHNICAL EFFICACY STAGE: 1.

Acute Application of Imidacloprid Alters the Sensitivity of Direction Selective Motion Detecting Neurons in an Insect Pollinator.

Cholinergic pesticides, such as the neonicotinoid imidacloprid, are the most important insecticides used for plant protection worldwide. In recent decades, concerns have been raised about side effects on non-target insect species, including altered foraging behavior and navigation. Although pollinators rely on visual cues to forage and navigate their environment, the effects of neonicotinoids on visual processing have been largely overlooked. To test the effect of acute treatment with imidacloprid at known concentrations in the brain, we developed a modified electrophysiological setup that allows recordings of visually evoked responses while perfusing the brain in vivo. We obtained long-lasting recordings from direction selective wide-field, motion sensitive neurons of the hoverfly pollinator, Eristalis tenax. Neurons were treated with imidacloprid (3.9 μM, 0.39 μM or a sham control treatment using the solvent (dimethylsulfoxide) only. Exposure to a high, yet sub-lethal concentration of imidacloprid significantly alters their physiological response to motion stimuli. We observed a general effect of imidacloprid (3.9 μM) increasing spontaneous activity, reducing contrast sensitivity and giving weaker directional tuning to wide-field moving stimuli, with likely implications for errors in flight control, hovering and routing. Our electrophysiological approach reveals the robustness of the fly visual pathway against cholinergic perturbance (i.e., at 0.39 μM) but also potential threatening effects of cholinergic pesticides (i.e., evident at 3.9 μM) for the visual motion detecting system of an important pollinator.

Dynamic Rupture Study of Near-Field Velocity Pulses during the 2016 Kumamoto Earthquake, Japan

ABSTRACT Simulating the ground motions of future earthquakes requires a proper understanding and modeling of source, path, and site effects. Ground motions recorded during recent earthquakes very close to their ruptured faults provide new evidence of the importance of source effects and suggest that physics-based rupture modeling is critical to account for them. Here, we develop dynamic rupture models to simulate the near-fault ground motions generated by the 2016 Kumamoto, Japan, earthquake (Mw 7.0) at Nishihara village, which feature a large-amplitude velocity pulse. Comparison of mainshock and foreshock waveforms suggests that the source of the velocity pulse is on the Futagawa fault segment located very close to the site. Our dynamic models use the spectral element method and are built upon a previous kinematic description of the event via a so-called “characterized source model,” with three strong-motion generation areas (SMGAs) on the assumed fault plane. We first develop a reference model that reproduces the main features of the rupture process in agreement with previous results of kinematic source inversion. We then examine the sensitivity of the simulated near-fault ground motions to the frictional parameters (critical slip-weakening distance and stress drop) in the shallow part of the fault and to the geometrical properties of the shallow SMGA. Even assuming drastically different frictional properties in the shallow part of the fault, the amplitude of the simulated ground motions was affected little. On the other hand, changes of geometrical properties of the shallow SMGA generated large differences in simulated ground motions. The results indicate that geometrical features of the shallow SMGA played a more important role in generating near-fault ground motions with velocity pulses as observed at Nishihara village during the 2016 Kumamoto earthquake.

An Overview of Protective Gloves with Regards to Hand Performance and the Evaluation Methods

Many tasks are carried out with the use of hands in various environments and working conditions, so protective gloves are widely utilized by workers voluntarily or as needed. The present study aims to introduce the hand, its various parts, and the importance of protecting the hands, which are subjected to several mechanical and perceptive situations. Moreover, the literature introduces the types of protective gloves, their design and structure. The factors affecting the performance of protective gloves and their evaluation methods are also included. This paper contains two parts; the first part is allocated to overview the importance of protective gloves and the second part is assigned to the published researches in each field and their results are elaborated. By probing the results of the previously conducted researches on protective gloves, it was found that wearing protective gloves often reduced the strength capability of the hand, tactile sensitivity, manual dexterity and range of motion, while the discrepancy in the results of some functions, such as pinch or torque, was observable in the studied researches. Examination of hand performance measurement tasks also showed weaknesses and shortcomings in some methods, and this was one of the causes of contradictions in the results of studies.

Optoelectronic devices for smart healthcare applications

The diverse vision systems found in nature can provide interesting design inspiration for imaging devices, ranging from optical subcomponents to digital cameras, with more desirable optical characteristics compared to conventional imagers. The advantages of natural vision systems include high visual acuity, wide field of view, wavelength-free imaging, improved aberration correction and depth of field, and high motion sensitivity. Recent advances in soft materials, ultrathin electronics/optoelectronics have facilitated the realization of novel processes and device designs that mimic biological vision systems. This presentation highlights recent progress and continued efforts in the research and development of optoelectronic devices and imaging systems for smart healthcare applications.

Flexible Wearable Sensors Based in Carbon Nanotubes Reinforced Poly(Ethylene Glycol) Diglycidyl Ether (PEGDGE): Analysis of Strain Sensitivity and Proof of Concept

The electromechanical capabilities of carbon nanotube (CNT) doped poly(ethylene glycol) diglycidyl ether (PEGDGE) have been explored. In this regard, the effect of both CNT content and curing conditions were analyzed. The electrical conductivity increased both with CNT content and curing temperature due to the lower gel time that leads to a lower reaggregation during curing. More specifically, the percolation threshold at 160 and 180 °C curing temperatures is below 0.01 wt.%, and this limit increases up to 0.1 wt.% at 140 °C for an 8 h curing cycle. Moreover, the strain monitoring capabilities were investigated, and the effect of contact resistance was also analyzed. The electrical contacts made with silver ink led to higher values of gauge factor (GF) but presented some issues at very high strains due to their possible detachment during testing. In every case, GF values were far above conventional metallic gauges with a very significant exponential behavior, especially at low CNT content due to a prevalence of tunneling mechanisms. Finally, a proof of concept of fingers and knee motion monitoring was carried out, showing a high sensitivity for human motion sensing.

Norm-Based Cutoffs as Predictors of Prolonged Recovery After Adolescent Sport-Related Concussion.

To identify predictors of prolonged recovery (ie, >28 days) using patient demographic factors and healthy, norm-based cutoffs on a multimodal test battery in adolescents after sport-related concussions (SRCs). Retrospective cohort. Patients were deemed recovered after successful completion of return-to-play/school protocols and received medical clearance. Community concussion clinic. Male and female adolescent student athletes diagnosed with a SRC and evaluated within 1 week of injury. Patient demographics, medical history, injury description, computerized neurocognitive testing, vestibular/ocular testing, and symptoms at initial clinical visit. Performance on clinical testing to predict recovery duration, classified as normal (<28 days) or prolonged (>28 days). A total of 201 adolescent student athletes (age = 15.3 ± 1.4 years) were included (female 35%). Average recovery duration for the entire cohort was 22.3 ± 13.3 days, with 22% (n = 45) of adolescent student athletes taking >28 days to recover. The final model was 88.3% accurate in classifying normal and prolonged recovery. Predictor variables included sex, loss of consciousness, history of ocular disorder, history of concussion, performance on visual motor speed composite, visual motion sensitivity symptom provocation and near point of convergence distance, number-naming total time, and symptom count. These findings suggest that using norm-based cutoffs from cognitive, oculomotor, and vestibulo-ocular testing and symptom reporting, clinicians can accurately predict a prolonged recovery (sensitivity = 81%) and normal recovery (specificity = 83%) in an adolescent, SRC cohort.

Twin vortex computer in fluid flow

Fluids exist universally in nature and technology. Among the many types of fluid flows is the well-known vortex shedding, which takes place when a fluid flows past a bluff body. Diverse types of vortices can be found in this flow as the Reynolds number increases. In this study, we reveal that these vortices can be employed for conducting certain types of computation. The results from computational fluid dynamics simulations showed that optimal computational performance is achieved near the critical Reynolds number, where the flow exhibits a twin vortex before the onset of the Kármán vortex shedding associated with the Hopf bifurcation. It is revealed that as the Reynolds number increases toward the bifurcation point, the input sensitivity of the twin vortex motion also increases, suggesting the modality of information processing within the system. Our finding paves a novel path to understand the relationship between fluid dynamics and its computational capability.

Selecting the Most Relevant Brain Regions to Classify Children with Developmental Dyslexia and Typical Readers by Using Complex Magnocellular Stimuli and Multiple Kernel Learning.

Increasing evidence supports the presence of deficits in the visual magnocellular (M) system in developmental dyslexia (DD). The M system is related to the fronto-parietal attentional network. Previous neuroimaging studies have revealed reduced/absent activation within the visual M pathway in DD, but they have failed to characterize the extensive brain network activated by M stimuli. We performed a multivariate pattern analysis on a Region of Interest (ROI) level to differentiate between children with DD and age-matched typical readers (TRs) by combining full-field sinusoidal gratings, controlled for spatial and temporal frequencies and luminance contrast, and a coherent motion (CM) sensitivity task at 6%-CML6, 15%-CML15 and 40%-CML40. ROIs spanning the entire visual dorsal stream and ventral attention network (VAN) had higher discriminative weights and showed higher act1ivation in TRs than in children with DD. Of the two tasks, CM had the greatest weight when classifying TRs and children with DD in most of the ROIs spanning these streams. For the CML6, activation within the right superior parietal cortex positively correlated with reading skills. Our approach highlighted the dorsal stream and the VAN as highly discriminative areas between children with DD and TRs and allowed for a better characterization of the “dorsal stream vulnerability” underlying DD.