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Author: Grafiati
Published: 30 May 2022
Last updated: 31 May 2022

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1

Levy-Tzedek, S., M. Ben Tov, and A. Karniel. "Rhythmic movements are larger and faster but with the same frequency on removal of visual feedback." Journal of Neurophysiology 106, no. 5 (November 2011): 2120–26. http://dx.doi.org/10.1152/jn.00266.2011.

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The brain controls rhythmic movement through neural circuits combining visual information with proprioceptive information from the limbs. Although rhythmic movements are fundamental to everyday activities the specific details of the responsible control mechanisms remain elusive. We tested 39 young adults who performed flexion/extension movements of the forearm. We provided them with explicit knowledge of the amplitude and the speed of their movements, whereas frequency information was only implicitly available. In a series of 3 experiments, we demonstrate a tighter control of frequency compared with amplitude or speed. We found that in the absence of visual feedback, movements had larger amplitude and higher peak speed while maintaining the same frequency as when visual feedback was available; this was the case even when participants were aware of performing overly large and fast movements. Finally, when participants were asked to modulate continuously movement frequency, but not amplitude, we found the local coefficient of variability of movement frequency to be lower than that of amplitude. We suggest that a misperception of the generated amplitude in the absence of visual feedback, coupled with a highly accurate perception of generated frequency, leads to the performance of larger and faster movements with the same frequency when visual feedback is not available. Relatively low local coefficient of variability of frequency in a task that calls for continuous change in movement frequency suggests that we tend to operate at a constant frequency at the expense of variation in amplitude and peak speed.
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2

Sanjoaquin, Miguel A., Paul N. Appleby, Elizabeth A. Spencer, and Timothy J. Key. "Nutrition and lifestyle in relation to bowel movement frequency: a cross-sectional study of 20 630 men and women in EPIC–Oxford." Public Health Nutrition 7, no. 1 (February 2004): 77–83. http://dx.doi.org/10.1079/phn2003522.

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AbstractObjective:To investigate the relationships between nutritional and lifestyle factors and bowel movement frequency.Design:Cross-sectional analysis using data from a prospective study. Mean numbers of bowel movements were calculated in relation to a range of factors. In addition, individuals were categorised according to frequency of bowel movements: fewer than 7 per week (‘less than daily’) versus 7 or more per week (‘daily’), and odds ratios were calculated from logistic regression models. Results for each factor were adjusted for the other factors under consideration.Setting:The European Prospective Investigation into Cancer and Nutrition, Oxford cohort (EPIC–Oxford), UK.Participants:In total, 20,630 men and women aged 22–97 years at recruitment. Thirty per cent of the subjects were vegetarians or vegans.Results:Women had fewer bowel movements on average than men, and were less likely to have daily bowel movements. Mean bowel movement frequency was higher in vegetarians (10.5 in men, 9.1 in women) and especially in vegans (11.6 in men, 10.5 in women) compared with participants who ate meat (9.5 in men, 8.2 in women). There were also significant positive associations between bowel movement frequency and body mass index (BMI), intakes of dietary fibre and non-alcoholic fluids, for both men and women. Vigorous exercise was positively associated with bowel movement frequency in women although results for men were less clear. Alcohol intake was positively associated with bowel movement frequency in men but not in women.Conclusion:Being vegetarian and especially vegan is strongly associated with a higher frequency of bowel movements. Moreover, having a high intake of dietary fibre and fluids and a high BMI are associated with an increase in frequency of bowel movements.
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3

Heazell, Alexander E. P., Jayne Budd, Minglan Li, Robin Cronin, Billie Bradford, Lesley M. E. McCowan, Edwin A. Mitchell, et al. "Alterations in maternally perceived fetal movement and their association with late stillbirth: findings from the Midland and North of England stillbirth case–control study." BMJ Open 8, no. 7 (July 2018): e020031. http://dx.doi.org/10.1136/bmjopen-2017-020031.

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ObjectiveTo report perception of fetal movements in women who experienced a stillbirth compared with controls at a similar gestation with a live birth.DesignCase–control study.Setting41 maternity units in the UK.ParticipantsCases were women who had a late stillbirth ≥28 weeks gestation (n=291) and controls were women with an ongoing pregnancy at the time of the interview (n=733). Controls were frequency matched to cases by obstetric unit and gestational age.MethodsData were collected using an interviewer-administered questionnaire which included questions on maternal perception of fetal movement (frequency, strength, increased and decreased movements and hiccups) in the 2 weeks before the interview/stillbirth. Five fetal movement patterns were identified incorporating the changes in strength and frequency in the last 2 weeks by combining groups of similar pattern and risk. Multivariable analysis adjusted for known confounders.Primary outcome measureAssociation of maternally perceived fetal movements in relation to late stillbirth.ResultsIn multivariable analyses, women who reported increased strength of movements in the last 2 weeks had decreased risk of late stillbirth compared with those whose movements were unchanged (adjusted OR (aOR) 0.18, 95% CI 0.13 to 0.26). Women with decreased frequency (without increase in strength) of fetal movements were at increased risk (aOR 4.51, 95% CI 2.38 to 8.55). Daily perception of fetal hiccups was protective (aOR 0.31, 95% CI 0.17 to 0.56).ConclusionsIncreased strength of fetal movements and fetal hiccups is associated with decreased risk of stillbirth. Alterations in frequency of fetal movements are important in identifying pregnancies at increased risk of stillbirth, with the greatest risk in women noting a reduction in fetal activity. Clinical guidance should be updated to reflect that increase in strength and frequency of fetal movements is associated with the lowest risk of stillbirth, and that decreased fetal movements are associated with stillbirth.Trial registrationnumberNCT02025530.
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4

Taylor, Jordan A., and Kurt A. Thoroughman. "Divided Attention Impairs Human Motor Adaptation But Not Feedback Control." Journal of Neurophysiology 98, no. 1 (July 2007): 317–26. http://dx.doi.org/10.1152/jn.01070.2006.

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When humans experience externally induced errors in a movement, the motor system's feedback control compensates for those errors within the movement. The motor system's predictive control then uses information about those errors to inform future movements. The role of attention in these two distinct motor processes is unclear. Previous experiments have revealed a role for attention in motor learning over the course of many movements; however, these experimental paradigms do not determine how attention influences within-movement feedback control versus across-movement adaptation. Here we develop a dual-task paradigm, consisting of movement and audio tasks, which can differentiate and expose attention's role in these two processes of motor control. Over the course of several days, subjects performed horizontal reaching movements, with and without the audio task; movements were occasionally subjected to transient force perturbations. On movements with a force perturbation, subjects compensated for the force-induced movement errors, and on movements immediately after the force perturbation subjects exhibited adaptation. On every movement trial, subjects performed a two-tone frequency-discrimination task. The temporal specificity of the frequency-discrimination task allowed us to divide attention within and across movements. We find that divided attention did not impair the within-movement feedback control of the arm, but did reduce subsequent movement adaptation. We suggest that the secondary task interfered with the encoding and transformation of errors into changes in predictive control.
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5

Hinze, Vasko Kilian, Ozge Uslu, Jessica Emily Antono, Melanie Wilke, and Arezoo Pooresmaeili. "The effect of subliminal incentives on goal-directed eye movements." Journal of Neurophysiology 126, no. 6 (December 1, 2021): 2014–26. http://dx.doi.org/10.1152/jn.00414.2021.

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Reward incentives motivate humans to exert more effort, and they do so even when rewards are subconsciously perceived. It has been unknown whether these effects also extend to eye movements that have lower energetic demands compared with other movement types. We devised a behavioral task that required fast execution of multiple eye movements. Subliminal rewards enhanced the frequency and peak velocity of saccadic eye movements, with the most reliable effect observed for saccadic frequency.
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6

Suzuki, Takako, Makoto Suzuki, Kilchoon Cho, Naoki Iso, Takuhiro Okabe, Toyohiro Hamaguchi, Junichi Yamamoto, and Naohiko Kanemura. "EEG Oscillations in Specific Frequency Bands Are Differently Coupled with Angular Joint Angle Kinematics during Rhythmic Passive Elbow Movement." Brain Sciences 12, no. 5 (May 14, 2022): 647. http://dx.doi.org/10.3390/brainsci12050647.

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Rhythmic passive movements are often used during rehabilitation to improve physical functions. Previous studies have explored oscillatory activities in the sensorimotor cortex during active movements; however, the relationship between movement rhythms and oscillatory activities during passive movements has not been substantially tested. Therefore, we aimed to quantitatively identify changes in cortical oscillations during rhythmic passive movements. Twenty healthy young adults participated in our study. We placed electroencephalography electrodes over a nine-position grid; the center was oriented on the transcranial magnetic stimulation hotspot of the biceps brachii muscle. Passive movements included elbow flexion and extension; the participants were instructed to perform rhythmic elbow flexion and extension in response to the blinking of 0.67 Hz light-emitting diode lamps. The coherence between high-beta and low-gamma oscillations near the hotspot of the biceps brachii muscle and passive movement rhythms was higher than that between alpha oscillation and passive movement rhythm. These results imply that alpha, beta, and gamma oscillations of the primary motor cortex are differently related to passive movement rhythm.
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7

Gerloff, Christian, Camilo Toro, Letizia Leocani, and Mark Hallett. "Movement-related cortical potentials during repetitive high-frequency finger movements: preliminary results." Electroencephalography and Clinical Neurophysiology 102, no. 1 (January 1997): P14. http://dx.doi.org/10.1016/s0013-4694(97)86270-0.

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8

Stanford, T. R., E. G. Freedman, and D. L. Sparks. "Site and parameters of microstimulation: evidence for independent effects on the properties of saccades evoked from the primate superior colliculus." Journal of Neurophysiology 76, no. 5 (November 1, 1996): 3360–81. http://dx.doi.org/10.1152/jn.1996.76.5.3360.

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1. Microstimulation is used to investigate how activity in the superior colliculus (SC) contributes to determining the properties of primate saccadic eye movements. The site of collicular stimulation, the duration of the stimulation train, and the frequency of the stimulation train are each varied to examine the relative contributions of the locus, duration, and level of collicular activity to determining saccade amplitude, direction, duration, and velocity. 2. For any given site of stimulation, a relationship between movement amplitude and train duration can be demonstrated. Movement amplitude is a monotonically increasing, but saturating, function of increasing train duration. The size of the largest movement is dictated by the site of stimulation. Within the range over which amplitude can be modulated, movement offset is linked to the offset of the stimulation train. As a result, each decrement or increment in train duration produces a corresponding decrement or increment in movement duration. 3. The peak velocity of an evoked movement is influenced by the frequency of stimulation; a higher frequency of stimulation produces a movement of higher velocity. 4. The effects of train duration and frequency can be traded to produce movements that have comparable amplitudes but different dynamic characteristics; high-velocity movements of short duration and low-velocity movements of long duration can be produced by stimulating with high-frequency, short-duration, and low-frequency, long-duration trains, respectively. Across stimulation frequencies, the amplitude of an evoked movement is best related to the total number of pulses in the stimulation train. 5. Because it is possible to compensate for reduced velocity by increasing the duration of the stimulation train, the same site-specific maximum amplitude can be attained with different frequencies of stimulation. 6. Small, but significant, changes in movement direction occur as a result of varying train duration or train frequency. 7. The latency to movement onset (i.e., interval from stimulation onset to movement onset) depends upon the frequency of stimulation. A higher frequency of stimulation produces a movement of shorter latency. 8. These data demonstrate that both the site of stimulation and the parameters of stimulation contribute to determining the properties of a movement evoked from the primate SC. In doing so, they contradict the results of early microstimulation studies that suggest that the properties of eye movements evoked from the primate SC are determined solely by the site of stimulation. The findings conflict with the traditional view of collicular function that suggests that the collicular motor representation is purely anatomic. Rather, these data support a revised view whereby the locus, duration, and level of collicular activity contribute to determining the properties of a primate saccadic eye movement. According to this view, independent information relating to desired displacement and saccade velocity are extracted from the spatiotemporal profile of collicular activity.
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9

Robles-Puente, Sergio. "Fundamental frequency movements in one-word imperatives." Journal of the Acoustical Society of America 137, no. 4 (April 2015): 2267. http://dx.doi.org/10.1121/1.4920272.

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10

Brogaard, Jonathan, Allen Carrion, Thibaut Moyaert, Ryan Riordan, Andriy Shkilko, and Konstantin Sokolov. "High frequency trading and extreme price movements." Journal of Financial Economics 128, no. 2 (May 2018): 253–65. http://dx.doi.org/10.1016/j.jfineco.2018.02.002.

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11

Van Acker, Gustaf M., Sommer L. Amundsen, William G. Messamore, Hongyu Y. Zhang, Carl W. Luchies, Anthony Kovac, and Paul D. Cheney. "Effective intracortical microstimulation parameters applied to primary motor cortex for evoking forelimb movements to stable spatial end points." Journal of Neurophysiology 110, no. 5 (September 1, 2013): 1180–89. http://dx.doi.org/10.1152/jn.00172.2012.

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High-frequency, long-duration intracortical microstimulation (HFLD-ICMS) applied to motor cortex is recognized as a useful and informative method for corticomotor mapping by evoking natural-appearing movements of the limb to consistent stable end-point positions. An important feature of these movements is that stimulation of a specific site in motor cortex evokes movement to the same spatial end point regardless of the starting position of the limb. The goal of this study was to delineate effective stimulus parameters for evoking forelimb movements to stable spatial end points from HFLD-ICMS applied to primary motor cortex (M1) in awake monkeys. We investigated stimulation of M1 as combinations of frequency (30–400 Hz), amplitude (30–200 μA), and duration (0.5–2 s) while concurrently recording electromyographic (EMG) activity from 24 forelimb muscles and movement kinematics with a motion capture system. Our results suggest a range of parameters (80–140 Hz, 80–140 μA, and 1,000-ms train duration) that are effective and safe for evoking forelimb translocation with subsequent stabilization at a spatial end point. The mean time for stimulation to elicit successful movement of the forelimb to a stable spatial end point was 475.8 ± 170.9 ms. Median successful frequency and amplitude were 110 Hz and 110 μA, respectively. Attenuated parameters resulted in inconsistent, truncated, or undetectable movements, while intensified parameters yielded no change to movement end points and increased potential for large-scale physiological spread and adverse focal motor effects. Establishing cortical stimulation parameters yielding consistent forelimb movements to stable spatial end points forms the basis for a systematic and comprehensive mapping of M1 in terms of evoked movements and associated muscle synergies. Additionally, the results increase our understanding of how the central nervous system may encode movement.
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12

Noah, J. Adam, Carol Boliek, Tania Lam, and Jaynie F. Yang. "Breathing Frequency Changes at the Onset of Stepping in Human Infants." Journal of Neurophysiology 99, no. 3 (March 2008): 1224–34. http://dx.doi.org/10.1152/jn.00868.2007.

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Breathing frequency increases at the onset of movement in a wide rage of mammals including adult humans. Moreover, the magnitude of increase in the rate of breathing appears related to the rate of the rhythmic movement. We determined whether human infants show the same type of response when supported to step on a treadmill. Twenty infants (ages 9.7 ± 1.2 mo) participated in trials consisting of sitting, stepping on the treadmill, followed by sitting again. Breathing frequency was recorded with a thermocouple, positioned under one naris and taped to a soother that the infant held in his/her mouth. A video camera, electrogoniometers, and force platforms under the treadmill belts recorded stepping movements. We found that the rate of breathing changed at the beginning of stepping. Most surprisingly, we found that when infants stepped at a frequency slower than their breathing frequency in sitting, the breathing frequency decreased. Average breathing frequency during stepping was positively correlated with stepping frequency. There was no evidence of entrainment between stepping and breathing. In conclusion, the rapid change in breathing frequency at the beginning of movement is functional in infants. The direction and magnitude of change in breathing is associated with the leg movements.
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13

Abbott, R. D., H. Petrovitch, L. R. White, K. H. Masaki, C. M. Tanner, J. D. Curb, A. Grandinetti, P. L. Blanchette, J. S. Popper, and G. W. Ross. "Frequency of bowel movements and the future risk of Parkinson’s disease." Neurology 57, no. 3 (August 14, 2001): 456–62. http://dx.doi.org/10.1212/wnl.57.3.456.

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Background: Constipation is frequent in PD, although its onset in relation to clinical PD has not been well described. Demonstration that constipation can precede clinical PD could provide important clues to understanding disease progression and etiology. The purpose of this report is to examine the association between the frequency of bowel movements and the future risk of PD.Methods: Information on the frequency of bowel movements was collected from 1971 to 1974 in 6790 men aged 51 to 75 years without PD in the Honolulu Heart Program. Follow-up for incident PD occurred over a 24-year period.Results: Ninety-six men developed PD an average of 12 years into follow-up. Age-adjusted incidence declined consistently from 18.9/10,000 person-years in men with <1 bowel movement/day to 3.8/10,000 person-years in those with >2/day (p = 0.005). After adjustment for age, pack-years of cigarette smoking, coffee consumption, laxative use, jogging, and the intake of fruits, vegetables, and grains, men with <1 bowel movement/day had a 2.7-fold excess risk of PD versus men with 1/day (95% CI: 1.3, 5.5; p = 0.007). The risk of PD in men with <1 bowel movement/day increased to a 4.1-fold excess when compared with men with 2/day (95% CI: 1.7, 9.6; p = 0.001) and to a 4.5-fold excess versus men with >2/day (95% CI: 1.2, 16.9; p = 0.025).Conclusions: Findings indicate that infrequent bowel movements are associated with an elevated risk of future PD. Further study is needed to determine whether constipation is part of early PD processes or is a marker of susceptibility or environmental factors that may cause PD.
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14

Stegemöller, Elizabeth L., Tanya Simuni, and Colum MacKinnon. "Effect of movement frequency on repetitive finger movements in patients with Parkinson's disease." Movement Disorders 24, no. 8 (May 1, 2009): 1162–69. http://dx.doi.org/10.1002/mds.22535.

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15

Espay, Alberto J., Anthony E. Lang, and Robert Chen. "Effect of movement frequency on repetitive finger movements in patients with Parkinson's disease." Movement Disorders 25, no. 2 (January 8, 2010): 252. http://dx.doi.org/10.1002/mds.22930.

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16

White, Olivier, Yannick Bleyenheuft, Renaud Ronsse, Allan M. Smith, Jean-Louis Thonnard, and Philippe Lefèvre. "Altered Gravity Highlights Central Pattern Generator Mechanisms." Journal of Neurophysiology 100, no. 5 (November 2008): 2819–24. http://dx.doi.org/10.1152/jn.90436.2008.

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In many nonprimate species, rhythmic patterns of activity such as locomotion or respiration are generated by neural networks at the spinal level. These neural networks are called central pattern generators (CPGs). Under normal gravitational conditions, the energy efficiency and the robustness of human rhythmic movements are due to the ability of CPGs to drive the system at a pace close to its resonant frequency. This property can be compared with oscillators running at resonant frequency, for which the energy is optimally exchanged with the environment. However, the ability of the CPG to adapt the frequency of rhythmic movements to new gravitational conditions has never been studied. We show here that the frequency of a rhythmic movement of the upper limb is systematically influenced by the different gravitational conditions created in parabolic flight. The period of the arm movement is shortened with increasing gravity levels. In weightlessness, however, the period is more dependent on instructions given to the participants, suggesting a decreased influence of resonant frequency. Our results are in agreement with a computational model of a CPG coupled to a simple pendulum under the control of gravity. We demonstrate that the innate modulation of rhythmic movements by CPGs is highly flexible across gravitational contexts. This further supports the involvement of CPG mechanisms in the achievement of efficient rhythmic arm movements. Our contribution is of major interest for the study of human rhythmic activities, both in a normal Earth environment and during microgravity conditions in space.
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17

Cornman, Hannah L., Jan Stenum, and Ryan T. Roemmich. "Video-based quantification of human movement frequency using pose estimation: A pilot study." PLOS ONE 16, no. 12 (December 20, 2021): e0261450. http://dx.doi.org/10.1371/journal.pone.0261450.

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Assessment of repetitive movements (e.g., finger tapping) is a hallmark of motor examinations in several neurologic populations. These assessments are traditionally performed by a human rater via visual inspection; however, advances in computer vision offer potential for remote, quantitative assessment using simple video recordings. Here, we evaluated a pose estimation approach for measurement of human movement frequency from smartphone videos. Ten healthy young participants provided videos of themselves performing five repetitive movement tasks (finger tapping, hand open/close, hand pronation/supination, toe tapping, leg agility) at four target frequencies (1–4 Hz). We assessed the ability of a workflow that incorporated OpenPose (a freely available whole-body pose estimation algorithm) to estimate movement frequencies by comparing against manual frame-by-frame (i.e., ground-truth) measurements for all tasks and target frequencies using repeated measures ANOVA, Pearson’s correlations, and intraclass correlations. Our workflow produced largely accurate estimates of movement frequencies; only the hand open/close task showed a significant difference in the frequencies estimated by pose estimation and manual measurement (while statistically significant, these differences were small in magnitude). All other tasks and frequencies showed no significant differences between pose estimation and manual measurement. Pose estimation-based detections of individual events (e.g., finger taps, hand closures) showed strong correlations (all r>0.99) with manual detections for all tasks and frequencies. In summary, our pose estimation-based workflow accurately tracked repetitive movements in healthy adults across a range of tasks and movement frequencies. Future work will test this approach as a fast, quantitative, video-based approach to assessment of repetitive movements in clinical populations.
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18

Shabi, Oren, Sari Natan, Avraham Kolel, Abhishek Mukherjee, Oren Tchaicheeyan, Haguy Wolfenson, Nahum Kiryati, and Ayelet Lesman. "Motion magnification analysis of microscopy videos of biological cells." PLOS ONE 15, no. 11 (November 5, 2020): e0240127. http://dx.doi.org/10.1371/journal.pone.0240127.

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It is well recognized that isolated cardiac muscle cells beat in a periodic manner. Recently, evidence indicates that other, non-muscle cells, also perform periodic motions that are either imperceptible under conventional lab microscope lens or practically not easily amenable for analysis of oscillation amplitude, frequency, phase of movement and its direction. Here, we create a real-time video analysis tool to visually magnify and explore sub-micron rhythmic movements performed by biological cells and the induced movements in their surroundings. Using this tool, we suggest that fibroblast cells perform small fluctuating movements with a dominant frequency that is dependent on their surrounding substrate and its stiffness.
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19

Scherer, Reinhold, Stavros P. Zanos, Kai J. Miller, Rajesh P. N. Rao, and Jeffrey G. Ojemann. "Classification of contralateral and ipsilateral finger movements for electrocorticographic brain-computer interfaces." Neurosurgical Focus 27, no. 1 (July 2009): E12. http://dx.doi.org/10.3171/2009.4.focus0981.

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Electrocorticography (ECoG) offers a powerful and versatile platform for developing brain-computer interfaces; it avoids the risks of brain-invasive methods such as intracortical implants while providing significantly higher signal-to-noise ratio than noninvasive techniques such as electroencephalography. The authors demonstrate that both contra- and ipsilateral finger movements can be discriminated from ECoG signals recorded from a single brain hemisphere. The ECoG activation patterns over sensorimotor areas for contra- and ipsilateral movements were found to overlap to a large degree in the recorded hemisphere. Ipsilateral movements, however, produced less pronounced activity compared with contralateral movements. The authors also found that single-trial classification of movements could be improved by selecting patient-specific frequency components in high-frequency bands (> 50 Hz). Their discovery that ipsilateral hand movements can be discriminated from ECoG signals from a single hemisphere has important implications for neurorehabilitation, suggesting in particular the possibility of regaining ipsilateral movement control using signals from an intact hemisphere after damage to the other hemisphere.
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Glimcher, P. W., and D. L. Sparks. "Effects of low-frequency stimulation of the superior colliculus on spontaneous and visually guided saccades." Journal of Neurophysiology 69, no. 3 (March 1, 1993): 953–64. http://dx.doi.org/10.1152/jn.1993.69.3.953.

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1. The first experiment of this study determined the effects of low-frequency stimulation of the monkey superior colliculus on spontaneous saccades in the dark. Stimulation trains, subthreshold for eliciting short-latency fixed-vector saccades, were highly effective at biasing the metrics (direction and amplitude) of spontaneous movements. During low-frequency stimulation, the distribution of saccade metrics was biased toward the direction and amplitude of movements induced by suprathreshold stimulation of the same collicular location. 2. Low-frequency stimulation biased the distribution of saccade metrics but did not initiate movements. The distribution of intervals between stimulation onset and the onset of the next saccade did not differ significantly from the distribution of intervals between an arbitrary point in time and the onset of the next saccade under unstimulated conditions. 3. Results of our second experiment indicate that low-frequency stimulation also influenced the metrics of visually guided saccades. The magnitude of the stimulation-induced bias increased as stimulation current or frequency was increased. 4. The time course of these effects was analyzed by terminating stimulation immediately before, during, or after visually guided saccades. Stimulation trains terminated at the onset of a movement were as effective as stimulation trains that continued throughout the movement. No effects were observed if stimulation ended 40–60 ms before the movement began. 5. These results show that low-frequency collicular stimulation can influence the direction and amplitude of spontaneous or visually guided saccades without initiating a movement. These data are compatible with the hypothesis that the collicular activity responsible for specifying the horizontal and vertical amplitude of a saccade differs from the type of collicular activity that initiates a saccade.
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21

G., Umashankar, Vimala Juliet, and Sheeba Santhosh. "Acquiring and processing of female EEG signals of various wrist movements for neuro prosthetic applications." International Journal of Engineering & Technology 7, no. 2.25 (May 3, 2018): 154. http://dx.doi.org/10.14419/ijet.v7i2.25.20497.

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Human brain contain neurons which generate electrical signals, this can be recorded through electro encephalograph(EEG). Sensory motor cortices are responsible for motor activity i.e., various body movements, among which wrist movement reveals frequency change in Alpha & Beta bands of EEG signal. The aim of this approach is to calculate frequency changes responsible for various wrist movements such as flexion, extension, clockwise rotation and anticlockwise rotation, pronation and supination of female in both eyes open and eyes close conditions using FFT, wavelet transform classifier, where the largest set of EEG data is reduced to dimensions and the spectral frequencies for particular wrist movements are classified and the statistical analysis is done of various trials for both eyes open and eyes close conditions in both time domain and frequency domain and the mean and standard deviation of various trials will be compared for eyes open and eyes close condition in both time domain and frequency domain and these values can be implemented for neuro prosthetic applications.
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Haishi, Kouichi, and Mitsuru Kokubun. "Developmental Trends in Pursuit Eye Movements among Preschool Children." Perceptual and Motor Skills 81, no. 3_suppl (December 1995): 1131–37. http://dx.doi.org/10.2466/pms.1995.81.3f.1131.

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The purpose of this study was to investigate the developmental differences in pursuit eye movements among preschool children. The subjects were 28 children aged 3 to 6 years old and 5 adults aged 22 to 37 years. The target was moved sinusoidally on the horizontal plane at 0.3-, 0.5-, and 0.7-Hz stimulus frequency. The power ratio which represented the smoothness of eye movements and the phase difference between eye movements and target movement was calculated. The power ratio decreased with increased stimulus frequency for all subjects, indicating that eye movements became less smooth. At all stimulus frequencies, the power ratio was higher for adults than for children. Among the three age groups of children, there was no statistically significant difference on this parameter. The phase shifted from a small amount of lead for no lag to the lag with faster stimulus frequency in adults, but the gap was not statistically significant. For children, there was a statistically significant difference across age groups on change in the phase difference. These findings may suggest that the developmental differences in pursuit eye movements of children across ages 3 to 6 years were clear in what related to the phase difference.
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23

Kirk, Andrew, and Kenneth M. Heilman. "Auricular Myoclonus." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 18, no. 4 (November 1991): 503–4. http://dx.doi.org/10.1017/s0317167100032236.

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ABSTRACT:We describe a young man with a two and a half year history of idiopathic irregular contractions of an antitragicus muscle in the absence of a more generalized movement disorder. These contractions persisted in sleep and could not be replicated voluntarily. Because proximal nerve block temporarily eliminated the movements and complex hand movements reduced their amplitude and frequency, we suspect a central generator. However, these movements were not associated with any known pathologic condition.
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Vanner, Stephen, and Lawrence C. Hookey. "Timing and Frequency of Bowel Activity in Patients Ingesting Sodium Picosulphate/Magnesium Citrate and Adjuvant Bisacodyl for Colon Cleansing Before Colonoscopy." Canadian Journal of Gastroenterology 25, no. 12 (2011): 663–66. http://dx.doi.org/10.1155/2011/950263.

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BACKGROUND: Despite the wealth of research investigating bowel cleansing efficacy, there are very little data on the timing or frequency of bowel movements after each agent is ingested.OBJECTIVE: To examine the effect of each component of a three-day combined sodium picosulphate/magnesium citrate (PSLX) and bisacodyl regimen on the timing and frequency of bowel activity in patients undergoing colonoscopy.METHODS: Outpatients booked for colonoscopy were asked to complete a diary of their bowel preparation that tracked the timing of bowel movements. Bowel preparation quality was assessed using the Ottawa Bowel Preparation Scale. Bowel activity was compared with baseline and correlated with colon cleansing. Subgroup analysis was performed examining the effect of timing of the procedure and split-dose regimens.RESULTS: One hundred patients undergoing colon cleansing received bisacodyl 10 mg at 17:00 three days and two days before the day of colonoscopy. In one group, both sachets of PSLX were given the night before colonoscopy, while the second group, whose colonoscopies were scheduled after 11:00, ingested one sachet the night before and the second sachet at 06:00 on the day of colonoscopy. Patients had a mean of 1.7 bowel movements per day in the seven days before starting the cleansing regimen. Both doses of bisacodyl tablets resulted in a significant increase in the mean number of bowel movements compared with baseline (3.3/day first dose; 3.8/day second dose [P=0.03 and 0.001, respectively]). Each dose of PSLX also resulted in a significant increase in bowel movement frequency compared with baseline, with means of 4.4, 6.3 and 4.5 bowel movements after each dose. The mean time to the final bowel movement following the second sachet of PSLX was 8.9 h when taken the night before, and 3.9 h when taken the morning of the procedure. Bowel preparation quality significantly correlated with bowel frequency when total bowel movements were considered and when only the effects of bisacodyl were accounted for (P<0.01 for each).DISCUSSION: These data demonstrate that the addition of bisacodyl before PSLX ingestion has a significant additive effect on bowel frequency and correlates with bowel cleansing quality. The timing of the resulting bowel movements have practical implications for sleep and travel times to endoscopy suites.
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Wells, Greg D., and James Duffin. "Frequency of movements and respiratory control in exercise." Respiratory Physiology & Neurobiology 161, no. 3 (May 2008): 221–22. http://dx.doi.org/10.1016/j.resp.2008.01.010.

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Haouzi, Philippe, and Bruno Chenuel. "Frequency of movements and respiratory control in exercise." Respiratory Physiology & Neurobiology 161, no. 3 (May 2008): 219–20. http://dx.doi.org/10.1016/j.resp.2008.01.011.

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Aittokallio, T., M. Gyllenberg, J. Järvi, O. Nevalainen, and O. Polo. "Detection of high-frequency respiratory movements during sleep." Computer Methods and Programs in Biomedicine 61, no. 3 (March 2000): 171–85. http://dx.doi.org/10.1016/s0169-2607(99)00043-7.

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Vanyukov, Polina M., Tessa Warren, Mark E. Wheeler, and Erik D. Reichle. "The emergence of frequency effects in eye movements." Cognition 123, no. 1 (April 2012): 185–89. http://dx.doi.org/10.1016/j.cognition.2011.12.011.

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Katsiampa, Paraskevi, Shaen Corbet, and Brian Lucey. "High frequency volatility co-movements in cryptocurrency markets." Journal of International Financial Markets, Institutions and Money 62 (September 2019): 35–52. http://dx.doi.org/10.1016/j.intfin.2019.05.003.

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Kadar, Endre E., R. C. Schmidt, and M. T. Turvey. "Constants underlying frequency changes in biological rhythmic movements." Biological Cybernetics 68, no. 5 (March 1993): 421–30. http://dx.doi.org/10.1007/bf00198774.

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Yanagisawa, Takufumi, Masayuki Hirata, Youichi Saitoh, Tetsu Goto, Haruhiko Kishima, Ryohei Fukuma, Hiroshi Yokoi, Yukiyasu Kamitani, and Toshiki Yoshimine. "Real-time control of a prosthetic hand using human electrocorticography signals." Journal of Neurosurgery 114, no. 6 (June 2011): 1715–22. http://dx.doi.org/10.3171/2011.1.jns101421.

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Object A brain-machine interface (BMI) offers patients with severe motor disabilities greater independence by controlling external devices such as prosthetic arms. Among the available signal sources for the BMI, electrocorticography (ECoG) provides a clinically feasible signal with long-term stability and low clinical risk. Although ECoG signals have been used to infer arm movements, no study has examined its use to control a prosthetic arm in real time. The authors present an integrated BMI system for the control of a prosthetic hand using ECoG signals in a patient who had suffered a stroke. This system used the power modulations of the ECoG signal that are characteristic during movements of the patient's hand and enabled control of the prosthetic hand with movements that mimicked the patient's hand movements. Methods A poststroke patient with subdural electrodes placed over his sensorimotor cortex performed 3 types of simple hand movements following a sound cue (calibration period). Time-frequency analysis was performed with the ECoG signals to select 3 frequency bands (1–8, 25–40, and 80–150 Hz) that revealed characteristic power modulation during the movements. Using these selected features, 2 classifiers (decoders) were trained to predict the movement state—that is, whether the patient was moving his hand or not—and the movement type based on a linear support vector machine. The decoding accuracy was compared among the 3 frequency bands to identify the most informative features. With the trained decoders, novel ECoG signals were decoded online while the patient performed the same task without cues (free-run period). According to the results of the real-time decoding, the prosthetic hand mimicked the patient's hand movements. Results Offline cross-validation analysis of the ECoG data measured during the calibration period revealed that the state and movement type of the patient's hand were predicted with an accuracy of 79.6% (chance 50%) and 68.3% (chance 33.3%), respectively. Using the trained decoders, the onset of the hand movement was detected within 0.37 ± 0.29 seconds of the actual movement. At the detected onset timing, the type of movement was inferred with an accuracy of 69.2%. In the free-run period, the patient's hand movements were faithfully mimicked by the prosthetic hand in real time. Conclusions The present integrated BMI system successfully decoded the hand movements of a poststroke patient and controlled a prosthetic hand in real time. This success paves the way for the restoration of the patient's motor function using a prosthetic arm controlled by a BMI using ECoG signals.
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Sosnik, Ronen, Sebastian Haidarliu, and Ehud Ahissar. "Temporal Frequency of Whisker Movement. I. Representations in Brain Stem and Thalamus." Journal of Neurophysiology 86, no. 1 (July 1, 2001): 339–53. http://dx.doi.org/10.1152/jn.2001.86.1.339.

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How does processing of information change the internal representations used in subsequent stages of sensory pathways? To approach this question, we studied the representations of whisker movements in the lemniscal and paralemniscal pathways of the rat vibrissal system. We recently suggested that these two pathways encode movement frequency in different ways. We proposed that paralemniscal thalamocortical circuits, functioning as phase-locked loops (PLLs), translate temporally coded information into a rate code. Here we focus on the two major trigeminal nuclei of the brain stem, nucleus principalis and subnucleus interpolaris, and on their thalamic targets, the ventral posteromedial nucleus (VPM) and the medial division of the posterior nucleus (POm). This is the first study in which these brain stem and thalamic nuclei were explored together in the same animals and using the same stimuli. We studied both single- and multi-unit activity. We moved the whiskers both mechanically and by air puffs; here we present air-puff-induced movements because they are more similar to natural movements than movements induced by mechanical stimulations. We describe the basic properties of the responses in these brain stem and thalamic nuclei. The responses in both brain stem nuclei were similar; responses to air puffs were mostly tonic and followed the trajectory of whisker movement. The responses in the two thalamic nuclei were similar during low-frequency stimulations or during the first pulses of high-frequency stimulations, exhibiting more phasic responses than those of brain stem neurons. However, with frequencies >2 Hz, VPM and POm responses differed, generating different representations of the stimulus frequency. In the VPM, response amplitudes (instantaneous firing rates) and spike counts (total number of spikes per stimulus cycle) decreased as a function of the frequency. In the POm, latencies increased and spike count decreased as a function of the frequency. Having described the basic response properties in the four nuclei, we then focus on a specific test of our PLL hypothesis for coding in the paralemniscal pathway. We used short-duration air puffs, much shorter than whisker movements during natural whisking. The activity in this situation was consistent with the prediction we made on the basis of the PLL hypothesis.
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McIntosh, Angus R., and Colin R. Townsend. "Do different predators affect distance, direction, and destination of movements by a stream mayfly?" Canadian Journal of Fisheries and Aquatic Sciences 55, no. 8 (August 1, 1998): 1954–60. http://dx.doi.org/10.1139/f98-082.

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We observed the directions and distances travelled by Nesameletus ornatus mayfly nymphs in stream channels (current velocity 18 cm·s-1) with either Eldon's galaxias (Galaxias eldoni), brown trout (Salmo trutta), or no fish. Short (<20 cm) upstream movements were most common, but movements up to 90 cm in both directions were recorded. Predators had no significant impact on movement direction or distance compared with controls when all movements were considered. Only movements in direct response to galaxias were significantly longer and more likely to be in a downstream direction than movements not directly associated with galaxias. In most cases the frequency of downstream drift distances fitted a negative exponential model. Our results showed that when current and turbulence were low, N. ornatus could have considerable control over their movement.
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Fedorov, Dmitry, Andrey Khitrov, Evgeny Veselkov, Yuliya Domracheva, and Oksana Kozyreva. "SYNTHESIS OF THE LOW-FREQUENCY VIBRATION EXCITER." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (June 16, 2021): 66–71. http://dx.doi.org/10.17770/etr2021vol3.6526.

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The article is devoted to synthesis of the low-frequency vibration exciter for checking of sensors of acceleration. In many areas of the modern equipment sensors of acceleration working in very low range of frequencies are widely used. For checking and graduation of such sensors the vibration exciter capable to provide rectilinear horizontal harmonic oscillations of the calibrated accelerometer in so low range of frequencies are required. Low frequencies of fluctuations cause the necessity of creation of big amplitudes of movements for ensuring the acceptable values of amplitudes of accelerations. The low-frequency electrodynamic vibration exciter with a magnetic suspension of mobile part which is a component of the National Standard of the vibration movement of the Russian Federation is so far created. However, development of the modern equipment demands expansion of frequency ranges to the area of ultralow frequencies. One of requirements shown to the vibration exciter working in the ultralow range of frequencies is increase in amplitude of horizontal movements of a mobile part as with small amplitudes the speed and acceleration of the harmonious law of the movements proportional according to the frequency of fluctuations and a square of this frequency, will have small amplitude values. One of problems of realization of a control system of the electric drive of the vibration exciter consists in that a mobile part possesses indifferent position of balance. The centre of fluctuations of a mobile part is not defined and can be in any point on magnetic conductor length. That fluctuations had the steady centre in an average point of a magnetic conductor without use of a mechanical spring, the drive is supplied with an additional control system of fluctuations, or a so-called electromagnetic spring.
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Nishizawa, Uichi, and Shigeki Toyama. "Phase Difference Control System for TR Motor." Applied Mechanics and Materials 841 (June 2016): 173–78. http://dx.doi.org/10.4028/www.scientific.net/amm.841.173.

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The authors have developed a translational and rotational motor in one device by ultrasonic drive technology. This motor has two degree of freedom, that is, translational movement and rotational movement (TR motor). Two movements are controlled independently or simultaneously such as screw movement. As the motor is driven by ultrasonic vibration at the resonant frequency, the motor (stator) is designed and optimized by FEM analysis. Based on the analysis of FEM, the authors have developed a TR motor successfully. It shows good controllability in both movements.
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Stegemöller, Elizabeth L., Tanya Simuni, and Colum D. MacKinnon. "Reply: Effect of movement frequency on repetitive finger movements in patients with Parkinson's disease." Movement Disorders 25, no. 2 (January 27, 2010): 252–53. http://dx.doi.org/10.1002/mds.22957.

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Lucidi, C. A., and S. L. Lehman. "Adaptation to fatigue of long duration in human wrist movements." Journal of Applied Physiology 73, no. 6 (December 1, 1992): 2596–603. http://dx.doi.org/10.1152/jappl.1992.73.6.2596.

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Subjects made fast, accurate, consistent wrist flexions under normal conditions and under conditions of low-frequency fatigue. Movements made 1 h after fatiguing exercise were indistinguishable from those made before exercise, even though twitch tensions were only approximately 60% of their fresh values. Electromyograms (EMGs) recorded from the fatigued muscles were, however, different from those recorded before exercise. EMGs during unfatigued movements showed multiple bursts typical for rapid movements. In the presence of low-frequency fatigue, the duration of the first burst was longer than that under normal conditions, and its onset occurred earlier relative to the initiation of movement. The area of the second agonist burst and, in some cases, the antagonist burst, was increased, although changes in their timings were unclear. We conclude that subjects adapted to low-frequency fatigue by changing the neural patterns controlling their muscles and present a simple model of excitation-contraction coupling that demonstrates how the observed changes in excitation can produce the same kinematics.
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Tada, Hideoki, and Shoichi Iwasaki. "Spontaneous Eyeblinks Elicited by Vertical Eye Movements." Perceptual and Motor Skills 60, no. 1 (February 1985): 191–200. http://dx.doi.org/10.2466/pms.1985.60.1.191.

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Two experiments were carried out to examine the relationship between eyeblinks and eye movements under a visual search task. Exp. I showed that the vertical eye movements brought about slightly more eyeblinks than the horizontal ones. In Exp. II, the vertical eye movements were accompanied with significantly more frequent eyeblinks than the horizontal ones. Upward saccadic eye movements especially were associated with the more frequent eyeblinks than the downward ones. These results suggested a possible relationship between the eyeblinks and Bell's phenomenon. However, the comparison of eyeblink rates between eye-movement and the no-eye-movement conditions in Exp. II indicated that in the latter condition eyeblinks were significantly more frequent than in the former condition. Some psychological factors were suggested as likely important determinants of the frequency of eyeblinks.
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Bell, Gordon J., Gary D. Snydmiller, and Alex B. Game. "An Investigation of the Type and Frequency of Movement Patterns of National Hockey League Goaltenders." International Journal of Sports Physiology and Performance 3, no. 1 (March 2008): 80–87. http://dx.doi.org/10.1123/ijspp.3.1.80.

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Twenty-four National Hockey League (NHL) goaltenders were observed to determine the types and frequency of their movements during actual games. A secondary purpose was to compare these movements across the 3 periods of game play and between 2 NHL seasons (2003–04 and 2005–06) as a result of several rule changes between seasons. The mean (± SD) age, height, body mass, and years of NHL experience of the goaltenders were 30 ± 4 y, 85.4 ± 4.4 kg, 184.0 ± 3.8 cm, 6.6 ± 4.0 y, respectively. The mean (± SD) number of times and type of movements used during a game in order of most frequent were vertical movement (43.7 ± 10.3), moving laterally (39.7 ± 12.7), moving into full-butterfly position (32.1), anterior–posterior movement in front of goal crease (31.5 ± 11.5), skating out of the goal area to play the puck (19.7 ± 6.3), and using a half butterfly on a single leg pad (left = 5.2 ± 1.9, right = 6.4 ± 2.1). Goaltenders played the puck less frequently during the final period of the game than during the first 2 periods and more frequently between the 2 different NHL seasons after certain rule changes. It was concluded that NHL goaltenders move most frequently vertically, laterally, and out of the net to play the puck. In addition, goaltenders moved out of the goal area to play the puck less often in the third period but more frequently after several league rule changes designed to reduce this movement.
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Haddock, Michael G., Jeff A. Sloan, John W. Bollinger, Gamini Soori, Preston D. Steen, and James A. Martenson. "Patient Assessment of Bowel Function During and After Pelvic Radiotherapy: Results of a Prospective Phase III North Central Cancer Treatment Group Clinical Trial." Journal of Clinical Oncology 25, no. 10 (April 1, 2007): 1255–59. http://dx.doi.org/10.1200/jco.2006.09.0001.

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Purpose To evaluate patient assessment of long-term effect of pelvic radiotherapy on bowel function. Patients and Methods As part of a prospective randomized trial evaluating the impact of sucralfate on bowel function in patients receiving pelvic radiotherapy, patient-assessed bowel function data were collected during radiotherapy and again at 4 weeks and 1 year after completion of radiotherapy. Results The number of bowel movements per day increased up to week 4 and then slowly decreased. At 1 year, the mean number of bowel movements per day had increased from 1.75 to 2.09 and the median from 1 to 2. All measures of adverse bowel function worsened during radiotherapy. Frequency of bowel movements and symptoms of frequency, nocturnal bowel movements, cramping, and bleeding returned close to baseline values by 1 year. Symptoms of urgency, clustering, and measures of incontinence were all persistent at 1 year. The mean increase in bowel function score at 1 year was 0.74 (range, −5 to 7). Conclusion Pelvic radiotherapy is associated with a slight increase in bowel movement frequency and decrease in several patient-reported measures of adverse bowel function. Several measures of adverse function persisted at 1 year.
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Nagano, Yasuharu, Shogo Sasaki, Yui Shimada, Takeshi Koyama, and Hiroshi Ichikawa. "High-Impact Details of Play and Movements in Female Basketball Game." Sports Medicine International Open 05, no. 01 (February 3, 2021): E22—E27. http://dx.doi.org/10.1055/a-1309-3085.

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AbstractThis study aimed to identify the high-impact details of play and movements with higher acceleration and their frequency during a female basketball match. Trunk acceleration was measured during a simulated basketball game with eight female players. The extracted instance was categorized, which generated at > 6 and 8 G resultant accelerations using a video recording and an accelerometer attached to the players’ trunk, as details of play and movements. The frequency and ratio of the details of play and movements regarding all detected movements were calculated. A total of 1062 and 223 play actions were detected for the resultant acceleration thresholds of > 6 and 8 G, respectively. For these acceleration thresholds, in terms of details of play, positioning on the half-court was the most frequently observed (29.6 and 23.8%, respectively). In terms of movements, deceleration was the most frequently detected movement (21.5 and 23.3%, respectively), followed by landing (7.6 and 15.7%, respectively). Deceleration during positioning on the half-court and defense as well as landing mostly after a shot were detected as high-impact frequent basketball-specific movements. The results also showed that characteristics of movements or playing style and playing position may have an effect on acceleration patterns during a basketball game.
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Bressan, Giulia, Giulia Cisotto, Gernot R. Müller-Putz, and Selina Christin Wriessnegger. "Deep Learning-Based Classification of Fine Hand Movements from Low Frequency EEG." Future Internet 13, no. 5 (April 21, 2021): 103. http://dx.doi.org/10.3390/fi13050103.

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The classification of different fine hand movements from electroencephalogram (EEG) signals represents a relevant research challenge, e.g., in BCI applications for motor rehabilitation. Here, we analyzed two different datasets where fine hand movements (touch, grasp, palmar, and lateral grasp) were performed in a self-paced modality. We trained and tested a newly proposed CNN, and we compared its classification performance with two well-established machine learning models, namely, shrinkage-linear discriminant analysis (LDA) and Random Forest (RF). Compared to previous literature, we included neuroscientific evidence, and we trained our Convolutional Neural Network (CNN) model on the so-called movement-related cortical potentials (MRCPs). They are EEG amplitude modulations at low frequencies, i.e., (0.3,3) Hz that have been proved to encode several properties of the movements, e.g., type of grasp, force level, and speed. We showed that CNN achieved good performance in both datasets (accuracy of 0.70±0.11 and 0.64±0.10, for the two datasets, respectively), and they were similar or superior to the baseline models (accuracy of 0.68±0.10 and 0.62±0.07 with sLDA; accuracy of 0.70±0.15 and 0.61±0.07 with RF, with comparable performance in precision and recall). In addition, compared to the baseline, our CNN requires a faster pre-processing procedure, paving the way for its possible use in online BCI applications.
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Kim, Jennifer A., James C. Eliassen, and Jerome N. Sanes. "Movement Quantity and Frequency Coding in Human Motor Areas." Journal of Neurophysiology 94, no. 4 (October 2005): 2504–11. http://dx.doi.org/10.1152/jn.01047.2004.

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Studies of movement coding have indicated a relationship between functional MRI signals and increasing frequency of movement in primary motor cortex and other motor-related structures. However, prior work has typically used block-designs and fixed-time intervals across the varying movements frequencies that may prevent ready distinction of brain mechanisms related to movement quantity and, especially, movement frequency. Here, we obtained functional MRI signals from humans working in an event-related design to extract independent activation related to movement quantity or movement frequency. Participants tapped once, twice, or thrice at 1, 2, or 3 Hz, and the tapping evoked activation related to movement quantity in the precentral and postcentral gyri, supplementary motor area, cerebellum, putamen, and thalamus. Increasing movement frequency failed to yield activation in these motor-related areas, although linear movement frequency affects occurred in nonmotor regions of cortex and subcortex. Our results do not replicate prior data suggesting movement frequency encoding in motor-related areas; instead we observed movement quantity coding in motor-related brain areas. The discrepancy between prior studies and this study likely relates to methodology concerns. We suggest that the movement quantity relationships in human motor areas and encoding of movement frequency in nonmotor areas may reflect a functional anatomical substrate for mediating distinct movement parameters.
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Yeom, Hong Gi, June Sic Kim, and Chun Kee Chung. "Macroscopic Neural Oscillation during Skilled Reaching Movements in Humans." Computational Intelligence and Neuroscience 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/2714052.

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The neural mechanism of skilled movements, such as reaching, has been considered to differ from that of rhythmic movement such as locomotion. It is generally thought that skilled movements are consciously controlled by the brain, while rhythmic movements are usually controlled autonomously by the spinal cord and brain stem. However, several studies in recent decades have suggested that neural networks in the spinal cord may also be involved in the generation of skilled movements. Moreover, a recent study revealed that neural activities in the motor cortex exhibit rhythmic oscillations corresponding to movement frequency during reaching movements as rhythmic movements. However, whether the oscillations are generated in the spinal cord or the cortical circuit in the motor cortex causes the oscillations is unclear. If the spinal cord is involved in the skilled movements, then similar rhythmic oscillations with time delays should be found in macroscopic neural activity. We measured whole-brain MEG signals during reaching. The MEG signals were analyzed using a dynamical analysis method. We found that rhythmic oscillations with time delays occur in all subjects during reaching movements. The results suggest that the corticospinal system is involved in the generation and control of the skilled movements as rhythmic movements.
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Mohamed, Ayman A. "EXPOSURE FREQUENCY IN L2 READING." Studies in Second Language Acquisition 40, no. 2 (May 19, 2017): 269–93. http://dx.doi.org/10.1017/s0272263117000092.

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AbstractThe present study brings together methods of extensive reading studies and eye-movement research to track the cognitive effects of exposure frequency on vocabulary processing and learning. Forty-two advanced second language learners of English read a stage 1 graded reader, Goodbye Mr. Hollywood, on a computer screen while their eye movements were recorded. The eye-tracking task was followed by comprehension questions and vocabulary posttests. Target vocabulary consisted of 20 pseudo words and 20 known words with a range of repetition from 1 to 30. Eye-movement data showed that readers spent more time on pseudo words than on familiar words and that fixation times decreased across encounters with more attention given to target words on early encounters. Repeated exposure supported form recognition but was not as significant for meaning recall and recognition. Total times spent on each encounter was positively associated with learning success in all vocabulary measures. The amount of attention, as reflected in total reading times on each pseudo word, positively predicted learning outcomes above and beyond the number of encounters. Results of the study add a cognitive dimension to the concept of engagement in lexical learning in the process of incidental learning from second language reading.
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Friedman, Wendy A., H. Philip Zeigler, and Asaf Keller. "Vibrissae motor cortex unit activity during whisking." Journal of Neurophysiology 107, no. 2 (January 15, 2012): 551–63. http://dx.doi.org/10.1152/jn.01132.2010.

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Rats generate stereotyped exploratory (5–12 Hz) vibrissa movements when navigating through their environment. Like other rhythmic behaviors, the production of whisking relies on a subcortical pattern generator. However, the relatively large vibrissae representation in motor cortex (vMCx) suggests that cortex also contributes to the control of whisker movements. The goal of this study was to examine the relationship between neuronal activity in vMCx and the kinematics of vibrissae movements. We recorded multiunit activity (MUA) and single units in the rhythmic region of vMCx while measuring vibrissa position in awake, head-restrained rats. The rats were engaged in one of two behavioral tasks where they were rewarded for either 1) producing noncontact whisking epochs that met specified criteria (epochs ≥4 Hz, whisks >5 mm) or 2) whisking to contact an object. There was significant coherence between the frequency of MUA and vibrissae movements during free-air whisking but not when animals were using their vibrissae to contact an object. Spike rate in vMCx was most frequently correlated with the amplitude of vibrissa movements; correlations with movement frequency did not exceed chance levels. These findings suggest that the specific parameter under cortical control may be the amplitude of whisker movements.
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Haishi, Kouichi, Hideyuki Okuzumi, and Mitsuru Kokubun. "Quantitative Evaluation of Pursuit Eye Movements with Frequency Analysis." Equilibrium Research 56, no. 1 (1997): 34–38. http://dx.doi.org/10.3757/jser.56.34.

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Yang, Changkook, and John W. Winkelman. "Clinical and Polysomnographic Characteristics of High Frequency Leg Movements." Journal of Clinical Sleep Medicine 06, no. 05 (October 15, 2010): 431–38. http://dx.doi.org/10.5664/jcsm.27931.

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Döşemeci, L., M. Cengiz, M. Yılmaz, and A. Ramazanoĝlu. "Frequency of spinal reflex movements in brain-dead patients." Transplantation Proceedings 36, no. 1 (January 2004): 17–19. http://dx.doi.org/10.1016/j.transproceed.2003.11.049.

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Tsang, Edward P. K., Ran Tao, Antoaneta Serguieva, and Shuai Ma. "Profiling high-frequency equity price movements in directional changes." Quantitative Finance 17, no. 2 (June 7, 2016): 217–25. http://dx.doi.org/10.1080/14697688.2016.1164887.

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