Extraction and Data Processing of Freestyle Skiing Based on Motion Biomechanics

Objectives: Based on the principle of motion biomechanics, this paper studied the extraction and data processing of freestyle ski signals. Firstly, the algorithm of SLIC depth information and movement information was described in detail, and then the test and data collection methods were explained. Methods: Secondly, the algorithm was tested by this algorithm and traditional algorithm in the data set on the results of the comparison, the superiority of this algorithm was verified. Results: and starting from the characteristics of the underlying information of scene, consider in significant areas of the visual stimulus level. Conclusion: but at the same time the attention mechanism of human visual system was affected by the high-level features.

Disentangling of Local and Wide-Field Motion Adaptation

Motion adaptation has been attributed in flying insects a pivotal functional role in spatial vision based on optic flow. Ongoing motion enhances in the visual pathway the representation of spatial discontinuities, which manifest themselves as velocity discontinuities in the retinal optic flow pattern during translational locomotion. There is evidence for different spatial scales of motion adaptation at the different visual processing stages. Motion adaptation is supposed to take place, on the one hand, on a retinotopic basis at the level of local motion detecting neurons and, on the other hand, at the level of wide-field neurons pooling the output of many of these local motion detectors. So far, local and wide-field adaptation could not be analyzed separately, since conventional motion stimuli jointly affect both adaptive processes. Therefore, we designed a novel stimulus paradigm based on two types of motion stimuli that had the same overall strength but differed in that one led to local motion adaptation while the other did not. We recorded intracellularly the activity of a particular wide-field motion-sensitive neuron, the horizontal system equatorial cell (HSE) in blowflies. The experimental data were interpreted based on a computational model of the visual motion pathway, which included the spatially pooling HSE-cell. By comparing the difference between the recorded and modeled HSE-cell responses induced by the two types of motion adaptation, the major characteristics of local and wide-field adaptation could be pinpointed. Wide-field adaptation could be shown to strongly depend on the activation level of the cell and, thus, on the direction of motion. In contrast, the response gain is reduced by local motion adaptation to a similar extent independent of the direction of motion. This direction-independent adaptation differs fundamentally from the well-known adaptive adjustment of response gain according to the prevailing overall stimulus level that is considered essential for an efficient signal representation by neurons with a limited operating range. Direction-independent adaptation is discussed to result from the joint activity of local motion-sensitive neurons of different preferred directions and to lead to a representation of the local motion direction that is independent of the overall direction of global motion.

An Application of Machine Learning to Predict Stiffness Discrimination Thresholds Using Haptics

The effectiveness of our interaction with the computer-generated environments is subject to our physical limitations in real life such as our ability of discriminating differences in stiffness or roughness. This ability, represented by Weber fractions, is usually quantified by means of psychophysical experimentation. The experimentation process is tedious and repetitive as it requires the same task to be completed by participants until the mastery at a certain stimulus level can be ensured before moving onto the next level. Moreover, these thresholds are dependent on the tested standard stimulus level and, therefore, need to be identified by separate experiments for every possible standard stimulus level. The purpose of the current study is to reduce the amount of experimentation and predict the thresholds for stiffness discrimination of individuals after being tested at a single stimulus level. The prediction models tested provide a moderate level of prediction power, but more features, potentially physical and demographical in nature, are needed to increase their effectiveness. The procedure described herein can be extended to any modality other than stiffness and, therefore, has the potential to predict overall palpation effectiveness of an individual after a feasible amount of data is obtained through experimentation.

Real-time finite element analysis allows homogenization of tissue scale strains and reduces variance in a mouse defect healing model

Mechanical loading allows both investigation into the mechano-regulation of fracture healing as well as interventions to improve fracture-healing outcomes such as delayed healing or non-unions. However, loading is seldom individualised or even targeted to an effective mechanical stimulus level within the bone tissue. In this study, we use micro-finite element analysis to demonstrate the result of using a constant loading assumption for all mouse femurs in a given group. We then contrast this with the application of an adaptive loading approach, denoted real time Finite Element adaptation, in which micro-computed tomography images provide the basis for micro-FE based simulations and the resulting strains are manipulated and targeted to a reference distribution. Using this approach, we demonstrate that individualised femoral loading leads to a better-specified strain distribution and lower variance in tissue mechanical stimulus across all mice, both longitudinally and cross-sectionally, while making sure that no overloading is occurring leading to refracture of the femur bones.

Effects Of Spectral Tuning Of White Light on Attention Level And Sleep Quality

Non-image-forming lighting effects reveal the multiple circadian influences of light on human behaviours. A psychophysical experiment was conducted in two sessions (morning and afternoon) for 60 days. The experiment was designed to explore the influence of different circadian lighting by spectral tuning with controlled CCT and illuminance on attention level, brain activity, and sleep quality by measuring PVSAT, EEG, and PSQI, respectively, by 20 participants. The results showed that the white lighting of high circadian stimulus level and high melanopic irradiance significantly enhances the attention level, brain activity, and sleep quality compared to low circadian stimulus level.

Factors Affecting Auditory Estimates of Virtual Room Size: Effects of Stimulus, Level, and Reverberation

When vision is unavailable, auditory level and reverberation cues provide important spatial information regarding the environment, such as the size of a room. We investigated how room-size estimates were affected by stimulus type, level, and reverberation. In Experiment 1, 15 blindfolded participants estimated room size after performing a distance bisection task in virtual rooms that were either anechoic (with level cues only) or reverberant (with level and reverberation cues) with a relatively short reverberation time of T60 = 400 milliseconds. Speech, noise, or clicks were presented at distances between 1.9 and 7.1 m. The reverberant room was judged to be significantly larger than the anechoic room ( p < .05) for all stimuli. In Experiment 2, only the reverberant room was used and the overall level of all sounds was equalized, so only reverberation cues were available. Ten blindfolded participants took part. Room-size estimates were significantly larger for speech than for clicks or noise. The results show that when level and reverberation cues are present, reverberation increases judged room size. Even relatively weak reverberation cues provide room-size information, which could potentially be used by blind or visually impaired individuals encountering novel rooms.

Notched and Nonnotched Stimuli Are Equally Effective at the Mixing Point Level in Sound Therapy for Tinnitus Relief

Background Broadband noise (nonnotched) and notched noise are common sound sources in sound therapy for tinnitus relief. Studies on sound therapy using nonnotched or notched stimuli have reported large and small tinnitus improvements depending on the participant. However, the more effective sound source remains unclear given the among-study methodology differences. Purpose This study aimed to evaluate the tinnitus relief effects of sound therapy using stimuli with different spectral characteristics. Research Design This was a prospective study involving within-subject (baseline vs. 12-month follow-up) measurements for two groups (notched noise group vs. broadband noise group). Study Sample We enrolled 30 adults with subjective and tonal tinnitus (notched noise group: 16, broadband noise group: 14). Intervention The participants underwent 3-hour daily sound therapy using either notched noise or broadband noise for 12 months. The stimulus level for sound therapy was set to each participant's mixing point. Data Collection and Analysis Tinnitus loudness and the Korean version of the Tinnitus Primary Function Questionnaire score were measured at baseline and at the 12-month follow-up time point. Results Both groups showed a significant improvement in tinnitus loudness and the Korean version of the Tinnitus Primary Function Questionnaire score. Conclusions Notched and nonnotched stimuli are equally effective at the mixing point in sound therapy for tinnitus relief. Individuals with difficulties in tinnitus frequency measurement could easily undergo sound therapy using nonnotched stimuli.

Probing the Neural Systems Underlying Flexible Dimensional Attention

Flexibly shifting attention between stimulus dimensions (e.g., shape and color) is a central component of regulating cognition for goal-based behavior. In the present report, we examine the functional roles of different cortical regions by manipulating two demands on task switching that have been confounded in previous studies—shifting attention between visual dimensions and resolving conflict between stimulus–response representations. Dimensional shifting was manipulated by having participants shift attention between dimensions (either shape or color; dimension shift) or keeping the task-relevant dimension the same (dimension same). Conflict between stimulus–response representations was manipulated by creating conflict between response-driven associations from the previous set of trials and the stimulus–response mappings on the current set of trials (e.g., making a leftward response to a red stimulus during the previous task, but being required to make a rightward response to a red stimulus in the current task; stimulus–response conflict), or eliminating conflict by altering the features of the dimension relevant to the sorting rule (stimulus–response no-conflict). These manipulations revealed activation along a network of frontal, temporal, parietal, and occipital cortices. Specifically, dimensional shifting selectively activated frontal and parietal regions. Stimulus–response conflict, on the other hand, produced decreased activation in temporal and occipital cortices. Occipital regions demonstrated a complex pattern of activation that was sensitive to both stimulus–response conflict and dimensional attention switching. These results provide novel information regarding the distinct role that frontal cortex plays in shifting dimensional attention and posterior cortices play in resolving conflict at the stimulus level.

Effect of Number of Electrodes Used to Elicit Electrical Stapedius Reflex Thresholds in Cochlear Implants

<b><i>Introduction:</i></b> When mapping cochlear implant (CI) patients with limited reporting abilities, the lowest electrical stimulus level that produces a stapedial reflex (i.e., the electrical stapedius reflex threshold [eSRT]) can be measured to estimate the upper bound of stimulation on individual or a subset of CI electrodes. However, eSRTs measured for individual electrodes or a subset of electrodes cannot be used to predict the global adjustment of electrical stimulation levels needed to achieve comfortable loudness sensations that can be readily used in a speech coding strategy. In the present study, eSRTs were measured for 1-, 4-, and 15-electrode stimulation to (1) determine changes in eSRT levels as a function of the electrode stimulation mode and (2) determine which stimulation mode eSRT levels best approximate comfortable loudness levels from patients’ clinical maps. <b><i>Methods:</i></b> eSRTs were measured with the 3 different electrical stimulation configurations in 9 CI patients and compared with behaviorally measured, comfortable loudness levels or M-levels from patients’ clinical maps. <b><i>Results:</i></b> A linear, mixed-effects, repeated-measures analysis revealed significant differences (<i>p</i> &#x3c; 0.01) between eSRTs measured as a function of the stimulation mode. No significant differences (<i>p</i> = 0.059) were measured between 15-electrode eSRTs and M-levels from patients’ clinical maps. The eSRTs measured for 1- and 4-electrode stimulation differed significantly (<i>p</i> &#x3c; 0.05) from the M-levels on the corresponding electrodes from the patients’ clinical map. <b><i>Conclusion:</i></b> eSRT profiles based on 1- or 4-electrode stimulation can be used to determine comfortable loudness level on either individual or a subset of electrodes, and 15-electrode eSRT profiles can be used to determine the upper bound of electrical stimulation that can be used in a speech coding strategy.