Oculomotor Control in Amputee Soccer Players

2020 ◽  
Vol 37 (1) ◽  
pp. 41-55
Author(s):  
Wojciech Jedziniak ◽  
Piotr Lesiakowski ◽  
Teresa Zwierko

The authors investigated the dynamics of saccadic parameters during a stationary oculomotor target task in amputee soccer players (n = 16), able-bodied soccer players (n = 16), and nonathletic control subjects (n = 16). Eye movements during the visual-search tasks were recorded binocularly using a mobile eye-tracking system, and the gaze parameters were analyzed (fixation duration, saccade duration, saccade amplitude, saccade average acceleration, saccade peak deceleration, saccade average velocity, and ocular mobility index). The average saccade acceleration in the amputee soccer players was significantly lower than in the able-bodied players (p = .021). Other saccade characteristics in disabled athletes were comparable to those of the able-bodied groups. Moreover, the able-bodied soccer players presented faster saccadic parameters than nonathletes in terms of saccade acceleration (p = .002), deceleration (p = .015), and velocity (p = .009). The modification of oculomotor functions may result from extensive practice and participation in ball games. The authors’ hypothesis that oculomotor functions in amputee soccer players may be impaired was not fully confirmed.

Author(s):  
Carlos Lago-Peñas ◽  
Anton Kalén ◽  
Miguel Lorenzo-Martinez ◽  
Roberto López-Del Campo ◽  
Ricardo Resta ◽  
...  

This study aimed to evaluate the effects playing position, match location (home or away), quality of opposition (strong or weak), effective playing time (total time minus stoppages), and score-line on physical match performance in professional soccer players using a large-scale analysis. A total of 10,739 individual match observations of outfield players competing in the Spanish La Liga during the 2018–2019 season were recorded using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions (central defenders, players = 94; external defenders, players = 82; central midfielders, players = 101; external midfielders, players = 72; and forwards, players = 67) and the following match running performance categories were considered: total distance covered, low-speed running (LSR) distance (0–14 km · h−1), medium-speed running (MSR) distance (14–21 km · h−1), high-speed running (HSR) distance (>21 km · h−1), very HSR (VHSR) distance (21–24 km · h−1), sprint distance (>24 km · h−1) Overall, match running performance was highly dependent on situational variables, especially the score-line condition (winning, drawing, losing). Moreover, the score-line affected players running performance differently depending on their playing position. Losing status increased the total distance and the distance covered at MSR, HSR, VHSR and Sprint by defenders, while attacking players showed the opposite trend. These findings may help coaches and managers to better understand the effects of situational variables on physical performance in La Liga and could be used to develop a model for predicting the physical activity profile in competition.


2021 ◽  
Vol 11 (5) ◽  
pp. 539
Author(s):  
Tamara Jakovljević ◽  
Milica M. Janković ◽  
Andrej M. Savić ◽  
Ivan Soldatović ◽  
Gordana Čolić ◽  
...  

Reading is one of the essential processes during the maturation of an individual. It is estimated that 5–10% of school-age children are affected by dyslexia, the reading disorder characterised by difficulties in the accuracy or fluency of word recognition. There are many studies which have reported that coloured overlays and background could improve the reading process, especially in children with reading disorders. As dyslexia has neurobiological origins, the aim of the present research was to understand the relationship between physiological parameters and colour modifications in the text and background during reading in children with and without dyslexia. We have measured differences in electroencephalography (EEG), heart rate variability (HRV), electrodermal activities (EDA) and eye movements of the 36 school-age (from 8 to 12 years old) children (18 with dyslexia and 18 of control group) during the reading task in 13 combinations of background and overlay colours. Our findings showed that the dyslexic children have longer reading duration, fixation count, fixation duration average, fixation duration total, and longer saccade count, saccade duration total, and saccade duration average while reading on white and coloured background/overlay. It was found that the turquoise background, turquoise overlay, and yellow background colours are beneficial for dyslexic readers, as they achieved the shortest time duration of the reading tasks when these colours were used. Additionally, dyslexic children have higher values of beta (15–40 Hz) and the broadband EEG (0.5–40 Hz) power while reading in one particular colour (purple), as well as increasing theta range power while reading with the purple overlay. We have observed no significant differences between HRV parameters on white colour, except for single colours (purple, turquoise overlay, and yellow overlay) where the control group showed higher values for mean HR, while dyslexic children scored higher with mean RR. Regarding EDA measure, we found systematically lower values in children with dyslexia in comparison to the control group. Based on the present results, we can conclude that both pastel and intense background/overlays are beneficial for reading of both groups and all sensor modalities could be used to better understand the neurophysiological origins in dyslexic children.


2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Fabio E Fontana ◽  
Alexandria Uding ◽  
Andrew Cleneden ◽  
Lindsey Cain ◽  
Lea Ann Shaddox ◽  
...  

The purpose of this project was to compare the gaze behavior of older adults to young adults during locomotor tasks requiring participants to change the direction and vary the speed of walking.Older adults were further divided into high- and low-risk of falling groups based on scores in the Berg balance scale and pre-established risk factor criteria. Gaze behavior was measured using the applied sciences eye tracking system as participants walked under four different conditions. The results suggest that, independent of group or target, fixations on target were shorter, the faster participants walked. Results also revealed that older adults at high-risk of falling tended to move their gaze off the to-be-stepped-on target before actually making heel contact with the target, whereas the young and older adults at low-risk of falling did not. Based on these results we recommend warning older adults about the negative effects of walking speed on their ability to recognize and comprehend the challenges on the ground ahead by suggesting they slow down when walking. Another strategy is to train older adults to make heel contact with the ground before transferring their gaze to another aspect of the environment, which may serve to reduce the likelihood of tripping.


2016 ◽  
Vol 11 (6) ◽  
pp. 846-852 ◽  
Author(s):  
A Scott ◽  
JJ Malone ◽  
R Morgans ◽  
D Burgess ◽  
W Gregson ◽  
...  

The aim of the investigation was to determine the relationship between blood creatine kinase and physical match performance in 15 elite male soccer players competing in the English Premier League. Blood samples were collected 48 h following a competitive match and analysed for creatine kinase concentration immediately after collection. Physical match performance data were collected using a computerised tracking system (Prozone®) from >6 matches for each player. Mean ± S.D creatine kinase concentration 48 h post-match was 520 ± 224 µ.mol.l−1. Large individual variation in creatine kinase response at this time point was observed (184 µ.mol.l−1 to 1573 µ.mol.l−1). No significant correlation coefficients were observed between the chosen indicators of physical match performance and creatine kinase concentration 48 h post-match. These data suggest that creatine kinase concentrations are elevated as a consequence of playing a soccer match. Creatine kinase may also be of limited value in supporting important decisions in the coaching process.


2012 ◽  
Vol 5 (4) ◽  
Author(s):  
Antoine Coutrot ◽  
Nathalie Guyader ◽  
Gelu Ionescu ◽  
Alice Caplier

Models of visual attention rely on visual features such as orientation, intensity or motion to predict which regions of complex scenes attract the gaze of observers. So far, sound has never been considered as a possible feature that might influence eye movements. Here, we evaluate the impact of non-spatial sound on the eye movements of observers watching videos. We recorded eye movements of 40 participants watching assorted videos with and without their related soundtracks. We found that sound impacts on eye position, fixation duration and saccade amplitude. The effect of sound is not constant across time but becomes significant around one second after the beginning of video shots.


Vision ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 39
Author(s):  
Julie Royo ◽  
Fabrice Arcizet ◽  
Patrick Cavanagh ◽  
Pierre Pouget

We introduce a blind spot method to create image changes contingent on eye movements. One challenge of eye movement research is triggering display changes contingent on gaze. The eye-tracking system must capture the image of the eye, discover and track the pupil and corneal reflections to estimate the gaze position, and then transfer this data to the computer that updates the display. All of these steps introduce delays that are often difficult to predict. To avoid these issues, we describe a simple blind spot method to generate gaze contingent display manipulations without any eye-tracking system and/or display controls.


2019 ◽  
Vol 11 (3) ◽  
pp. 168781401881953
Author(s):  
Guichao Ren ◽  
Xiaohua Zhao ◽  
Zhanzhou Lin ◽  
Wenxiang Xu

The development of freeway construction and the increasing coverage of the road network have led to increasing requirements for guide signs. This article investigated drivers’ visual cognition pattern regarding exit guide signs on freeway interchanges. A static visual cognition experiment with 32 participants was carried out. The route information volume (four levels) and destination information volume (seven levels) were selected as the variables. An eye-tracking system was utilized to record drivers’ eye movement indicators, such as eye movement time, saccade frequency, seek time, and fixation duration. The results indicated that the eye movement time, saccade frequency, and seek time are highly correlated with information volume and increase significantly with the increases in information volume; although the fixation duration has no correlation with information volume, the fixation duration value, saccade frequency, and seek time of destination information are significantly higher than those of route information, and the destination information fulfills a stronger guiding function during the driver’s trip. The corresponding threshold values of destination information are 5, 5, 4, and 3 under the four levels of route information, and the threshold value of route information is 3.


Author(s):  
Despina Vasileva ◽  

A study about perception of a page from a textbook of Bulgarian is presented in the article. Participants in the experiment are 30 students of age 15 to 19 from high schools in Sofia. The study is realized through an eye tracking system. For the purposes of the study 8 stimuli (textbook pages) were constructed, containing the components as follows: “text”, “image”, and “diagram”. In each stimulus the quantity of the components differs. All possible pairs in a combination in the left and in the right field of view are presented in the stimuli. The goal of the research is to be examined the fixation of the gaze on each elements of a textbook page. To assess the characteristic of the gaze was calculated the number of saccades in the left and right visual field of the slides. The data are organized in spreadsheets. Statistical analysis is performed in two-group t-test (two samples with different variances). Mean number of saccades, standard deviation, standard error, critical ratio are calculated.


Author(s):  
Miguel Lorenzo-Martínez ◽  
Francisco J. Corredoira ◽  
Carlos Lago-Peñas ◽  
Roberto López-Del Campo ◽  
Fabio Nevado-Garrosa ◽  
...  

AbstractThe aim of this study was to examine the effects of chronological age on acceleration and deceleration match performance in professional soccer players. A total of 5317 individual match observations were collected on 420 professional players competing in the Spanish LaLiga during the 2018–2019 season, using a multiple-camera computerised tracking system (TRACAB; ChyronHego, Melville, NY, USA). Players were classified using a k-means cluster analysis into four different age groups: 17–23 years, 24–27 years, 28–30 years, and 31–38 years. Linear mixed models were adjusted to compare the players’ match performance according to their age group and playing position (central defenders, external defenders, central midfielders, external midfielders, and forwards). The results showed that players aged between 31–38 years performed a significantly less total number of accelerations (ES=0.30–0.48) and decelerations (ES=0.29–0.49) in comparison with younger players. These age-related physical performance declines were more pronounced among central defenders, central midfielders, and forwards. However, no significant effects were obtained for players’ maximum acceleration and deceleration capacities. The current findings provide useful information for coaches and strength and conditioning specialists to better understand the effects of age on players’ physical performance and to develop age-tailored training programs.


2020 ◽  
Vol 41 (12) ◽  
pp. 858-866
Author(s):  
Lars Reinhardt ◽  
Stephan Schulze ◽  
Rene Schwesig ◽  
Eduard Kurz

AbstractThis investigation examined the position-specific physical performance in different locomotor categories and physiological demands concurrently in official games of sub-elite players and to present a new performance index (PI). Time-motion (distance, velocity, acceleration) and heart rate data of 55 soccer players were simultaneously captured via a GPS tracking system. The relationship between external and internal match-load (PI) was determined on the basis of heart rate, average velocity and acceleration. In contrast to the mean heart rate (85.2±3.2%, P=0.806, ηp²=0.03), the average total distance covered (9946±715 m) was largely affected by players’ position (P<0.001, ηp²=0.63). Furthermore, a mixed design ANOVA showed a large interaction effect between position and locomotor category (P<0.001, ηp²=0.44). On average, PI was 1.57±0.37 m/min²/%, with notably lower values in the 2nd half. The position-specific profiles already reported for higher leagues were also present in sub-elite soccer players. Despite lower values for total distance and smaller distances in the high-intensity zones (>14.4 km/h), internal loads were comparable to those observed in European top leagues. In comparison to a performance measure that ignores accelerations, PI was shown to be less dependent on the playing position and had higher variability. Consequently, PI is better suited to distinguish between players’ performance.


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