Age-related differences of the gaze pattern in a realistic pedestrian traffic task

Laboratory studies suggest that the gaze pattern changes in older age, both in seated and in walking persons. Here we investigate the gaze pattern in a more complex and realistic scenario: walking in a virtual-reality shopping precinct. Seventeen young and sixteen older adults walked at their preferred speed on a treadmill driven by their leg movements, thus controlling the presentation of a virtual 3D world on a screen 130 cm ahead. The screen showed a shopping street with stationary and moving objects, and with six pedestrian traffic lights of whom three turned red upon approach. Gaze direction was registered by a video-based system. We found that each glance at a traffic light took longer in older than in young persons, and the sum of all glances at a traffic light was longer as well. In effect, older persons looked at the traffic light equally long throughout all three light phases, while young ones gradually increased their inspection of the traffic light as the green phase went on. The observed change of the gaze pattern in older age could represent a compensatory strategy to facilitate spatial orientation and/or movement preparation, or it could reflect a deficit of gaze disengagement. Future research should disambiguate these alternatives. In any case, the observed change is detrimental for seniors’ sensorimotor performance in everyday scenarios

Age Differences of Gaze Distribution during Pedestrian Walking in a Virtual-Reality Environment

The gaze pattern changes in old age, not only during artificial laboratory tasks but also during quasi-natural behavior. We have recently reported that older adults, walking in a virtual reality pedestrian precinct, spent longer time looking at pedestrian traffic lights than young adults did (Bock et al, 2015). We have interpreted this age-related change as a compensatory strategy, and we now analyze whether this strategy might be potentially hazardous in that it withdraws gaze from other regions that are critical for safe walking. Seventeen young and 16 older adults walked on a non-motorized treadmill linked to the 3D model of a pedestrian precint. The model was displayed on a monitor ahead, such that participants felt as if walking through the simulated world. Along their way, participants met a range of familiar objects such as pedestrian traffic lights, oncoming pedestrians and cats crossing their path. Eye position was recorded by a video-based system. We found that compared to young adults, older ones looked longer at regions of high behavioral relevance and less long at regions of low behavioral relevance. We conclude that looking longer at relevant regions might be a strategy for compensating central processing deficits, but this strategy may not pay off when an unexpected threat emerges in a seemingly irrelevant region

SESSION-RPE IS A VALUABLE INTERNAL LOAD EVALUATION METHOD IN BEACH VOLLEYBALL FOR BOTH GENDERS, ELITE AND AMATEUR PLAYERS, CONDITIONING AND TECHNICAL SESSIONS, BUT LIMITED FOR TACTICAL TRAINING AND GAMES

This study aimed to verify the validity of session-RPE method to monitor the internal training load (ITL) in beach volleyball players by considering sessions related to different genders, competition levels (elite or amateur), and types of session (conditioning, technical, or tactical/game). Session-RPE and Edwards’ methods were applied to quantify the ITLs of 12 elite (18 players; 197 individual sessions) and 12 amateur (18 players;189 individual sessions) training sessions. Very large relationships between the two methods emerged for both competition level (Elite: r=.77; Amateur: r=.75) and gender (male: r=.76; female: r=.75) subgroups, and conditioning sessions (r=.75). Large relationships emerged for technical (r=.61) sessions, whereas tactical/game sessions resulted only in moderate relationships (r=.36). Beach volleyball coaches could adequately use session-RPE method to monitor training for players of different genders, competition levels, and types of session, although tactical/game sessions should be considered with some caution

“How” is more important than “how much” for game possession in elite northern hemisphere rugby union

The present study aimed to analyse technical and tactical aspects of rugby teams competing in the 2016/17 PRO12 Championship (12 professional club teams from Wales, Scotland, Italy, and Ireland) according to: margin of victory (close and balanced games, 1\u20139 and 10\u201326 points of difference in final score, respectively), ranking position [the four best placed clubs from each nation (the 1 st \u20134 th team) and the three following ranked clubs (the 5 th \u20137 th team)], and game outcome and ranking combined (winning and losing performances in the 1 st \u20134 th and 5 th \u20137 th team subgroups). One hundred and thirty-two games were analyzed according to 20 key performance indicators. A non-parametric approach was applied to evaluate differences (p 640.05) between teams. In close games, winning teams reported less possession (p=0.039), defended more (tackles made, p=0.039), and carried the ball less than losing counterparts (p=0.05), whereas in balanced games, winning teams were found to be much better than losers in \u201ctries for\u201d (p<0.0001) as well as \u201ctries against\u201d (p<0.0001), and \u201cclear breaks\u201d (p=0.0003). The teams of the 1 st \u20134 th subgroups were found to be more oriented to provide a solid defence than the 5 th \u20137 th winning teams, which were more offensive oriented (possession, p=0.01; gain line carries, p=0.001; passes, p<0.0001). Finally, a similar scenario to that of balanced games emerged for winning and losing performances in the 1 st \u20134 th and 5 th \u20137 th team subgroups. Coaches and physical trainers of elite northern hemisphere rugby union teams should be aware that successful performances mainly consist of a strong defence, tackling, scrumming, breaking the defensive line and high occurrences of possessions during the attacking phase