An information theory analysis of duration of lifeguards' scanning

Observers recorded the duration of scanning by six lifeguards in three indoor swimming pools. Duration of scanning was significantly predicted by the absolute numbers of child swimmers (< 17 years) in the pools and when numbers of child swimmers were represented in terms of bits of information. Duration of scanning increased as a linear function of both numbers of children and child bits of information. These results are interpreted in terms of the Hick-Hyman law of information theory. Lifeguards appear to simplify the task of information processing and decision-making by concentrating on children as a more at-risk group of swimmers. Duration of scanning was not significantly related to changes in number of adult swimmers.     

Does supervision by a lifeguard make a difference in rule violations? Effects of lifeguards' scanning.

Systematic observations were made of five lifeguards at indoor public swimming pools. Scanning by lifeguards was associated with lower incidences of rule violations by swimmers. Greater numbers of lifeguards patrolling the pool areas tended to reduce violations. Rules violations tended to be fewer when adult-to-child ratios were low, suggesting that monitoring by a parent or an adult may encourage rule compliance.     

Does incident severity influence surveillance by lifeguards in aquatic scenes?

Do lifeguards monitor events according to the level of danger they pose to the patron? This study examined this question by displaying 40 min of video of natural swimming activity to three lifeguards while an eye‐tracker recorded their eye position. In a separate session, those same lifeguards viewed 100 short video clips of some of the incidents that had been presented earlier and they were asked to provide a severity rating (0–7) for each one. The proportion of time that an event was monitored was calculated, and was not consistently predicted by incident severity, physical salience, or incident duration, but by the number of swimmers in the scene. Although this study had an extremely small number of lifeguards and should be treated as exploratory, it suggests that lifeguards may have trouble monitoring incidents they deem severe when they are presented in the context of a busy aquatic scene.     

Gaze behaviour of experienced and novice beach lifeguards – An exploratory in situ study

For lifeguards, recognizing a swimmer in trouble is a key factor in the rescue process. Although reports show that lifeguards outperform non‐lifeguards in their surveillance task, it is unclear to what extent this difference is reflected in gaze behaviour. In the current study, gaze behaviour of nine novice and seven experienced beach lifeguards was recorded for 45 min while they were on active duty. Results showed that fixation duration of experienced lifeguards was longer and more variable than that of novice lifeguards, and that these differences were more pronounced when looking at the task‐relevant region (i.e., swimming zone). Compared to experienced lifeguards, novices were found to be more distracted by the task‐irrelevant regions when there were more people swimming. These findings suggest that experienced lifeguards use a more flexible and task‐related gaze strategy, and that there might be differences in visual information processing between novice and experienced beach lifeguards.     

The Effect of Lifeguard Experience upon the Detection of Drowning Victims in a Realistic Dynamic Visual Search Task

Lifeguard surveillance is a complex task that is crucial for swimmer safety, though few studies of applied visual search have investigated this domain. This current study compared lifeguard and non‐lifeguard search skills using dynamic, naturalistic stimuli (video clips of confederate swimmers) that varied in set size and type of drowning. Lifeguards were more accurate and responded faster to drowning targets. Differences between drowning targets were also found: Passive drownings were responded to less often, but more quickly than active drownings, highlighting that passive drownings may be less salient but are highly informative once detected. Set size effects revealed a dip in reaction speeds at an intermediate set‐size level, suggesting a possible change in visual search strategies as the array increases in size. Nonetheless, the ability of the test to discriminate between lifeguards and non‐lifeguards offers future possibilities for training and assessing lifeguard surveillance skills. Copyright © 2017 John Wiley & Sons, Ltd.     

BEHAVIORAL COMMUNITY INTERVENTION TO REDUCE THE RISK OF SKIN CANCER

Peer leader modeling, posted feedback, posted goals, and a commitment raffle were used at two swimming pools to increase behaviors associated with skin cancer prevention. During the intervention condition, pool lifeguards modeled the protective behaviors by wearing sunglasses, t-shirts, and hats, using zinc oxide and sunscreen, and staying in the shade. Children and adolescents (1 to 16 years old) increased their use of two or more protective behaviors from a baseline mean of 6.5% to 26.9% during the intervention. Adults (older than 16 years) increased their protective behaviors from a baseline mean of 22% to 37.95% during the intervention. The lifeguards increased their use of all the protective behaviors from a baseline mean of 16.7% to 63.5% during intervention. Ways to improve and expand this intervention are discussed.     

Infant temperament and the brainstem auditory evoked response in later childhood.

Brainstem auditory evoked responses (BAERs) were evaluated on 10-12-year-old children (N = 56) who had been classified as high or low reactive to unfamiliar stimuli at 4 months of age. BAER measurement was selected because high reactive infants tend to become inhibited or fearful young children, and adult introverts have a faster latency to wave V of the BAER than do extroverts. Children previously classified as high reactive at 4 months had larger wave V components than did low reactive children, a finding that possibly suggests greater excitability in projections to the inferior colliculus. The fact that a fundamental feature of brainstem activity differentiated preadolescent children belonging to two early temperamental groups supports the value of gathering physiological data in temperament research.     

Line bisection by left-handed preschoolers: A phenomenon of symmetrical neglect

When a normal dextral attempts to bisect a horizontal line placed across his/her midline, there is a tendency for the transection to be placed slightly to the left of true center, a tendency which may be a little more pronounced when the left hand is used. However, left-handed children at or younger than 5 years of age err substantially to the left with the left hand and to the right with the right hand. This symmetrical neglect of extents contralateral to the hand currently in use, which may possibly reflect relatively greater commissural immaturity in left-handers, was not seen in dextral children of comparable ages, whose performance closely followed adult patterns.     

A comparison of the kinematics of the dolphin kick in humans and cetaceans

Prerecorded video footage of 9 female and 13 male Olympic level athletes swimming underwater by using the dolphin kick was analyzed and comparisons of the stroke kinematics were made with a previous analysis of cetacean swimming conducted by Rohr and Fish (Rohr, J. J., & Fish, F. E. (2004). Strouhal numbers and optimization of swimming by odontocete cetaceans. The Journal of Experimental Biology, 207, 1633-1642). The velocities of the swimmers ranged from 1.12 m/s to 1.85 m/s which corresponded to a range of effort levels. While some swimmers performed the dolphin kick on their backs (dorsal), others employed the prone (ventral) or the side (lateral) position and no distinctions were made between these positions when considering the results. The raw quantities measured were body length L (from the fingertips of the outstretched arms to the tips of the toes), time T(L) taken by the swimmer to traverse a body length, kick amplitude A at the toes, and the number of video frames per kick. These allowed us to determine the average velocity U of the swimmer, the kick frequency f, the reduced or length-specific velocity U/L (body lengths traversed per second), and the non-dimensional quantities kick amplitude A/L, the Strouhal number fA/U (ratio of tip or toe speed to forward speed) and the quantity fL/U (kicks per body length traversed). Trends of these dimensional and non-dimensional quantities were examined for the swimmers and compared to the cetaceans. Results showed that humans and cetaceans have comparable non-dimensional kick amplitudes, but kick frequency in humans was greater than for cetaceans swimming at equivalent speeds. Human swimmers required up to five kicks per body length traveled, while cetaceans require only 1.3. Length-specific velocities reached a maximum of 0.81 for humans and this was about half that of cetaceans. Human swimmers had a mean Strouhal number of 0.80, which was above the range considered optimal for underwater undulatory propulsion.     

The importance of reflection and evaluation processes in daily training sessions for progression toward elite level swimming performance

Self-regulated learning (SRL) involves self-directed metacognitive subprocesses and motivational beliefs that facilitate more effective and efficient learning. We investigated whether youth swimmers who are on track to becoming elite swimmers apply SRL subprocesses more frequently in their daily training sessions compared with swimmers who are not on this track. Insights into swimmers’ use of training-centered SRL could advance understanding about underlying individual characteristics that contribute to optimal engagement in daily training and, consequently, progression toward elite level swimming performance. We collected data on training-centered SRL subprocesses (evaluation, planning, reflection, speaking up, effort and self-efficacy) and performance data for 157 youth swimmers aged 12–21 years (73 males and 84 females). The results of a multivariate analysis of covariance revealed significantly higher scores for reflection processes during training for high-performing swimmers but lower scores for effort compared with lower-performing swimmers (p < 0.05). A closer examination of the high-performing group showed that those demonstrating greater improvement during a season scored significantly higher for evaluation processes after training compared with those evidencing less improvement during a season (p < 0.05). Significant between-group differences in SRL subprocesses remained after adjusting for differences in weekly training hours. Youth swimmers on track to becoming elite swimmers are characterized by more frequent use of reflection processes during training and evaluation processes after training, which suggests that these swimmers’ learning and training processes are more effective and efficient. Ultimately, this could contribute to a higher quality of daily training, which may result in greater improvements during a season, higher performance levels, and a greater chance of reaching the level of elite swimming performance.     

Time perception is enhanced by task duration knowledge: Evidence from experienced swimmers

The present study deals with the impact on temporal estimation of previous knowledge about the duration of a specific task (referred to as ??task duration knowledge??). Athletes were recruited in this study because they are assumed to have high levels of task duration knowledge in their discipline. In Experiment 1, 28 elite swimmers had to estimate the time it would take to swim a given distance using two different strokes for which they had different task duration knowledge levels. The swimmers estimated duration more accurately and with less uncertainty in the high-knowledge than in the low-knowledge condition. In Experiment 2, the swimmers had to produce 36?s of swimming in various contexts that altered the retrieval of their task duration knowledge, with and without a secondary task. When swimmers could not rely on their task duration knowledge, their productions were more affected by the secondary task. In Experiment 3, the swimmers were more precise at producing time when visualising something that they knew well (swimming) rather than something that they had never experienced, which shows that physical execution is not a mandatory requirement for observing the enhancement effect resulting from task duration knowledge. These three converging experiments suggest that task duration knowledge is strongly involved in time perception.     

Lifeguards and Physically Risky Prosocial Groups: A comparison based on personality theory

The goal of this study is to explore the personality of experienced professional lifeguards in terms of Eysenck and Eysenck's PEN model of personality and Zuckerman's sensation seeking trait. A sample of 144 male professional lifeguards were contrasted with three different samples: (1) a general population sample; (2) a sample of individuals engaged in physically risky sports; and (3) a sample of prosocial physically risky professionals. It was found that lifeguards resembled most closely the prosocials followed by the sportsmen and finally the general population. The most frequent and largest differences between lifeguards and the comparison groups were found on extraversion, experience seeking, and neuroticism. The implications for lifeguard selection procedures and future research are discussed.     

Adult-child interaction under dyadic and polyadic conditions

The nature of adult-child interaction was examined under two conditions: dyadic (adult with one child) and polyadic (adult with four children). The subjects were staff and children in day nurseries, who were observed in a specially set-up task situation. In certain respects the interaction assumed different forms depending on group condition. The effects may be seen in stylistic differences in the adults' behaviour: thus in polyads individual children had not only less speech directed to them but also speech that tended to be more directive and prohibitive. While the total number of bids the adults received from children in polyads was considerably greater than in dyads, the increase was a selective one, referring only to requests for help and not to less urgent demands. The main strategy adopted by adults to cope with the increase in demand was by ignoring, the incidence of which was very much greater under polyadic than under dyadic conditions. Joint involvement of adult and child was also much reduced in the former setting. The implications of these findings for children reared under group care conditions are discussed, and attention is drawn to the importance of situational factors in determining caretaker responsiveness.     

Evaluation of a coaching strategy to reduce swimming stroke errors with beginning age-group swimmers

A coaching strategy to decrease errors in swimming strokes with swimmers who had not improved under "standard" coaching procedures was investigated using a multiple baseline design across subjects and swimming strokes. The procedure resulted in a large decrease in errors on swimming strokes during sessions in a training pool. Stimulus generalization of improved performance to normal practice conditions in the regular pool was observed with all but one swimmer. This improvement was maintained during two maintenance phases lasting approximately 2 weeks, as well as under standard coaching conditions during at least a 2-week follow-up. For two swimmers, error rates on one of the strokes showed a gradual increase between the third and fifth week of follow-up, but brief remedial prompting sessions immediately corrected their performance. Some beneficial response generalization to other components of the stroke being trained was observed, but no improvements were found on untrained strokes. The error correction package did not disrupt practice, require excessive amounts of the coach's time, or necessitate the use of cumbersome apparatus. In addition, the coach and the swimmers considered the procedures to be effective, and expressed their willingness to participate in them again in the future.     

Memory scanning by children: Meaningfulness and mediation

Two experiments were performed for the purpose of isolating factors that influence speed of memory scanning by children. The first experiment revealed an interaction involving age and type of stimulus. Young children required relatively greater time to process ambiguous stimuli. The second experiment, involving a pretraining phase designed to induce mediation, showed that preschool children scan representations more rapidly when given instructions to apply a mediator.     

Locomotor estimation of distance after visual scanning by children and adults

Subjects (120 young adults and 120 children) were tested for their abilities to estimate visually the distance to a target 5 m away, then walk unaided by vision to that target as accurately as possible. Experimental groups were determined by visual scanning time (1, 5, or 10 s), delay between the end of visual scanning and the start of locomotion (0, 1, 3, or 5 s), and by age (9 year old children or young adult). Adults performed locomotor distance estimations based on visual scanning more accurately than children under all conditions. Increased scanning time resulted in more accurate performances by children but not by adults, and increased delays between the end of scanning and the start of locomotion caused decreases in accuracy for children only. These decrements were partially ameliorated by increased scanning time. The total time spent without vision after scanning the target (delay time plus walking time) was an important factor, with sharp increases in error for all delay conditions for children. The results are discussed in terms of trace decay effects and developmental aspects of visual guidance of locomotion.     

Conservation training in four-year-old children

In Experiment 1 two training procedures were used to teach four-year-olds to conserve. Verbal rule instruction consisted of providing verbal rules and demonstrations of the operations referred to by the rules. Feedback consisted of providing verbal feedback contingent upon the children's responses. One week after training on conservation of number and length the children were given a posttest which included tests of conservation of number, length, and mass. Children who were given verbal rule instruction conserved significantly more on the number and length posttest problems than children who were not. However, this learning did not transfer to the mass problems, possibly because mass is not naturally acquired until some time after conservation of number and length. The feedback training procedure had no effect on conservation performance. In Experiment 2, the verbal rule instruction procedure was used to train four-year-olds on conservation of length and mass. One week after training the children were tested on both conservation of number, which is typically acquired before length and mass, and conservation of weight, which is typically acquired after length and mass, as well as on conservation of length and mass. Children who were given training conserved more on all four types of problems than children in the control group.     

Time,number and length: Similarities and differences in discrimination in adults and children

The aim of this study was to focus on similarities in the discrimination of three different quantities—time, number, and line length—using a bisection task involving children aged 5 and 8 years and adults, when number and length were presented nonsequentially (Experiment 1) and sequentially (Experiment 2). In the nonsequential condition, for all age groups, although to a greater extent in the younger children, the psychophysical functions were flatter, and the Weber ratio higher for time than for number and length. Number and length yielded similar psychophysical functions. Thus, sensitivity to time was lower than that to the other quantities, whether continuous or not. However, when number and length were presented sequentially (Experiment 2), the differences in discrimination performance between time, number, and length disappeared. Furthermore, the Weber ratio values as well as the bisection points for all quantities presented sequentially appeared to be close to that found for duration in the nonsequential condition. The results are discussed within the framework of recent theories suggesting a common mechanism for all analogical quantities.     

Two-year-olds use artist intention to understand drawings

Adults appreciate that an abstract visual representation can be understood through inferring the artist's intention. Many investigators have argued that this capacity is a late-emerging developmental accomplishment, a claim supported by findings that preschool children ignore explicit statements about intent when naming pictures. Using a simplified method, we explored picture naming in 2-year-olds. Experiment 1 found that when an adult artist drew an object, children later mapped a novel name for the drawing to the object that the adult had been looking at. Experiment 2 suggests that this response was not merely because there was more attention given to that object. These findings are consistent with the view that children are naturally disposed to reason about artifacts, including artwork, in terms of inferred intention.     

Preschoolers distribute scarce resources according to the moral valence of recipients' previous actions

Children aged 3 years and 4? years old watched a puppet, struggling to achieve goals, who was helped by a 2nd puppet and violently hindered by a 3rd. The children then distributed wooden biscuits between the helper and hinderer. In Experiment 1, when distributing a small odd number of biscuits, 4?-year-olds (N = 16) almost always gave more to the helper. Children verbally justified their unequal distributions by reference to the helper's prosocial behavior or the hinderer's antisocial behavior. In Experiment 2, when biscuits were more plentiful, 4?-year-olds (N = 16) usually gave equal numbers to helper and hinderer, indicating that 4?-year-olds usually preferred not to distribute unequally unless forced to by resource scarcity. Three-year-olds (N = 16 in Experiment 1, N = 20 in Experiment 3) gave more biscuits equally often to the helper and to the hinderer. In many cases, this was because they were confused as to the identities and actions of the puppets, possibly because they were shocked by the hinderer's actions. Two fundamental moral behaviors are therefore demonstrated in young preschoolers: indirect reciprocity of morally valenced acts and a preference for equality when distributing resources, although the cognitive bases for these behaviors remain unclear. These results join other recent studies in demonstrating that the seeds of complex moral understanding and behavior are found early in development.