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Progestin-induced changes in play behaviour of the prepubertal rat.

The effects of neonatal exposure to medroxyprogesterone acetate on later play behaviour was studied. The experiments reported here indicate that animals of both sexes exposed to the hormone neonatally show lower levels of rough-and-tumble play in the prepubertal period. The effect is primarily one on play initiation: the organisation of play behaviour once initiated is not significantly affected, and the effect on play does not seem to be secondary to effects on some other behaviour. Several hypotheses are considered that might account for these findings.

Animals↗

Suppression of play fighting by amphetamine: effects of catecholamine antagonists, agonists and synthesis inhibitors.

Moderate doses of amphetamine and methylphenidate profoundly depress play fighting in juvenile rats. To test the idea that this behavioral effect was dependent on the release of catecholamines (CAs) we administered haloperidol (0.05-0.8 mg/kg), chlorpromazine (0.5-5 mg/kg), phenoxybenzamine (0.5-20 mg/kg) or propranolol (0.5-20 mg/kg) alone or in combination with 0.5 or 1 mg/kg d-amphetamine sulfate. None of these CA antagonists reversed the suppression of play fighting (indexed by pinning) caused by amphetamine, but at higher doses haloperidol, chlorpromazine and phenoxybenzamine depressed both pinning and rearing. The presynaptic NE agonist clonidine (0.05-0.2 mg/kg) also failed to block the effects of amphetamine on play; instead it too depressed both pinning and rearing. Finally the CA synthesis inhibitor, alpha-methyltyrosine (total dose: 100 mg/kg) did not attenuate the suppression of play by amphetamine. Ephedrine (10-80 mg/kg) mimicked the effects of amphetamine on pinning, but apomorphine did not. At doses from 0.125-0.5 mg/kg apomorphine stimulated pinning while 1 mg/kg had no effect. The present findings confirm earlier reports that amphetamine suppresses play fighting but the mechanism of action remains obscure.

Aggression↗

A behavioral analysis of the effects of amphetamine on play and locomotor activity in the post-weaning rat.

Amphetamine has been shown to canalize or direct the activity of a young rat towards ethologically relevant stimuli. In the five-day-old, amphetamine increases the speed of approach to the nipple of an anesthetized dam; in the 15-day-old, amphetamine increases motor activity and directs it toward an anesthetized adult, however, in the juvenile rat amphetamine reportedly disrupts species-specific behaviors such as huddling and play. The present experiments further assessed the effects of amphetamine in the post-weaning rat by measuring drug-induced behaviors in the presence of an alert and anesthetized companion. In Experiment 1, subjects were videotaped in the presence of an alert non-treated, same-age rat and components of play, a predominant behavior of the post-weaning rat, were recorded. Results confirmed previous reports that low doses of amphetamine (0.5 mg/kg) disrupt play behavior, however, in the present experiment higher doses of amphetamine (1.0 mg/kg) did not disrupt the percentage of time spent in play. Further analysis of drug-induced behavior revealed that the 1.0 mg/kg amphetamine-injected rat engaged in play with the companion, although the drug-treated animal did exhibit marked alterations in the flexibility of its motor patterns. The second experiment confirmed that amphetamine did not disrupt the amount of time a juvenile rat spent with an anesthetized age-mate. In fact, amphetamine-induced activity was directed towards the anesthesized same-age rat. Following amphetamine treatment, all subjects were active nearly 100% of the observation period whether they were tested alone or in the presence of an anesthetized same-age rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

The role of the striatum in organizing sequences of play fighting in neonatally dopamine-depleted rats.

Juvenile rats sustaining dopamine depletions by intraventricular injections of 6-hydroxydopamine (6-OHDA) as neonates were used to study the role of the striatum in controlling play fighting. As juveniles, the rats exhibited all the behavior elements typical of play fighting. However, they were more likely to use defensive tactics that shortened the playful contact between partners; and when contacting the partner, they were more likely to switch to other behaviors, such as allogrooming and sexual mounting, rather than continue with the play sequence. It is suggested here that the striatum is important for maintaining sequential organization of play fighting.

Aggression↗

Physiological stress response to video-game playing: the contribution of built-in music.

Recent studies on video game playing have uncovered a wide range of measurable physiological effects on the organism, such as increases in cardiovascular activity and breathing responses. However, the exact source of these effects remains unclear. Given the well-known effects of sound on physiological activity, especially those of noise and of music, and on the secretion of the stress hormone cortisol in particular, we hypothesized that music may be a major source of stress during video game playing. We thus examined the effect of built-in music on cortisol secretion as a consequence of video game playing. Players were assigned quasi-randomly to either a Music or a Silence condition. Four saliva samples were taken, that is, after practice (T1), immediately after having played for 10 minutes (T2), 15 minutes after the end of the experiment (T3), and 30 minutes after the end of the experiment (T4). The results show that the Music group had significantly higher cortisol levels at T3, that is, when cortisol levels are assumed to reflect the stress induced by the game. These findings suggest for the first time that the auditory input contributes significantly to the stress response found during video game playing.

Adult↗

The playing habits and other commitments of elite junior Australian football players.

The Victorian Football League Under 18 (VFL U18) competition provides a pathway to the elite senior level of Australian football. Players involved in the VFL U18 competition also play football in other contexts, including for school and local clubs, and can have considerable additional work and educational demands. A total of 103 elite junior Australian football players from six VFL U18 clubs participated in a survey that asked about their football playing habits and other commitments. The median age of players when they first joined their VFL U18 squad was 16.3 years. The players participated in a median of five weekly training sessions during the last two weeks of the 1999 preseason and played a median of five preseason games. Fifty percent of the players expected to participate in 3-4 training sessions per week and 25% expected to play more than two games per week during the 1999 season. Half of the players reported ambitions to play Australian Football League (AFL) football. Further research is needed to determine whether or not high participation levels have negative impacts on performance and injury risk in these players.

Adolescent↗

Playing conditions, player preparation and rugby injury: a case-control study.

This paper investigates the effect of player preparation, ground conditions and weather conditions upon the injury risk for Rugby Union players. A population-based case-control study was performed using a sample (n= 1043) of New Zealand Rugby Union players aged 16 y and above. Details concerning game preparation (warm-up and usual position), and ground and weather conditions (precipitation, wind and temperature) were obtained from the players. If players were injured during the season (n= 624) they were asked to provide details about the game in which they were last injured. Uninjured players (n= 419) provided details about the last game in which they played. Injuries were more likely to occur when games were played on hard grounds or in calm or warm conditions. Playing out of position and the duration of warming up did not significantly alter the risk of injury. When player preparation, ground and weather conditions, grade, age, playing position and rugby experience were simultaneously controlled for, hard ground and the absence of wind were associated with increased risk. The influence of these factors may be indirect, through adaptation to the conditions in which a game is played.

Adolescent↗

Promoting respect for the rules and injury prevention in ice hockey: evaluation of the fair-play program.

OBJECTIVE: To reduce the number of transgressions to the rule, the occurrence of violent acts and to prevent injuries, Hockey Québec adopted the Fair-Play Program (FPP). The objective of the present study was to evaluate the effectiveness of the FPP. METHODS: 52 Bantam (14-15 years) teams participated in this cohort study. In total, 49 games (13 with the FPP, 36 without FPP) were systematically assessed for transgressions to the rule. Body checking was allowed in all games. Transgressions to the rule data were obtained using a real time observation system in a natural setting, while injury data were collected through a self-administered questionnaire. Data were analysed using generalised linear models with generalised estimating equations accounting for potential team effect. RESULTS: The number of penalties per game was significantly lower (p < 0.01) for games played with the FPP. Overall, no difference was noted in the number of transgressions observed during games played with or without the FPP. Players in leagues where the FPP was used held their opponents more frequently (p < 0.0001). On the other hand, players in leagues without the FPP shoved and hit more (p = 0.05). No difference was noted in the injury rate for games played with or without the FPP. CONCLUSIONS: This study showed that the FPP is one of the tools available to help those in the hockey world promote fair play values. Moreover, this project clearly showed the importance of program evaluation and the value of direct observation in a natural setting.

Adolescent↗

Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules Football: a case study.

A purpose of this study was to determine if pre-season anthropometric and physiological measures were significantly different for the players from one Australian Football League (AFL) club selected to play in the first game of the season compared to the players not selected. Another purpose was to compare fitness test results for defenders, forwards and mid-fielders in the same AFL club. Thirty-four players were tested for isolated quadriceps and hamstrings strength, leg extensor muscle strength and power, upper body strength, sprinting speed, vertical jump (VJ), endurance, skinfolds and hamstring flexibility. The starters who were selected to play the first game were a significantly older and more experienced playing group, and were significantly better (p < 0.05) in measures of leg power, sprinting speed and the distance covered in the Yo Yo intermittent recovery test compared to the non-starters. Although there were trends for the superiority of the starters, the differences in lower and upper body strength, VJ and predicted VO2max were non-significant. The forwards generally produced the worst fitness scores of the playing positions with the midfielders having significantly lower skinfolds and the defenders possessing better hamstring strength and VJ compared to the forwards. It was concluded that some fitness qualities can differentiate between starters and non-starters, at least in one AFL club. Comparisons of playing positions and the development of fitness norms for AFL players require further research.

Adult↗

Heart rate increase to alcohol administration and video lottery terminal play among probable pathological gamblers and nonpathological gamblers.

The authors examined heart-rate responses to alcohol consumption and video lottery terminal (VLT) play. Regular VLT players (30 probable pathological gamblers [PPGs]; 30 nonpathological gamblers [NPGs]) were randomized to an alcohol (mean postdrinking blood alcohol concentration = 0.056%) or placebo condition. Heart rate was recorded at pre- and postdrinking baselines and during VLT play. Consistent with an earlier study, alcohol-condition participants displayed elevated heart rates relative to placebo-condition participants only at postdrinking and VLT play. Moreover, alcohol-condition participants showed a greater heart rate increase to VLT play than did placebo-condition participants. However, PPGs were not more susceptible to alcohol- and/or VLT play-induced heart rate accelerations than were NPGs. Implications for gambling/alcohol-disorder comorbidity are discussed.

Adult↗

Measuring problem video game playing in adolescents.

AIMS: Some researchers suggest that for some people, video game playing is an addictive behaviour similar to substance dependence. Our aim was to design and validate a scale to measure the problems associated with the apparently addictive use of all types of video games and video game systems, because there is no instrument at the present time that can be used for this purpose. DESIGN: We reviewed the DSM-IV criteria for substance dependence and for pathological gambling, as well as the literature on the addictions in order to design a short scale (PVP; problem video game playing) that is quick and easy to apply. PARTICIPANTS: The scale was administered to 223 Spanish adolescents aged between 13 and 18 years. The study was carried out in Granada and Algeciras, Spain. FINDINGS: Psychometric analyses show that the PVP seems to be unidimensional and has acceptable internal consistency (Cronbach's alpha) at 0.69. The pattern of associations between the scale scores and alternative measures of problem play supports its construct validity (higher total scores in the scale were associated with higher frequency of play, mean and longest times per session, self and parents' perception of playing to excess, and scores in the Severity of Dependence Scale). CONCLUSIONS: Our results confirm that the excessive use of video games is associated with a number of problems which resemble a dependence syndrome, and the PVP appears as a useful instrument for the measurement of such problems.

Adolescent↗

Performance characteristics according to playing position in elite soccer.

The paper provides a large-scale study into the motion characteristics of top class soccer players, during match play, according to playing position. Three hundred top-class outfield soccer players were monitored during 20 Spanish Premier League and 10 Champions League games using a computerized match analysis system (Amisco Pro, Nice, France). Total distance covered in five selected categories of intensity, and the mean percentage of playing time spent in each activity were analyzed according to playing position. Midfield players covered a significantly greater total distance (p < 0.0001) than the groups of defenders and forwards did. Analyzing the different work rates showed significant differences (p < 0.5 - 0.0001) between the different playing positions. There were no significant differences between halves in the total distance covered, or in distances covered at submaximal and maximal intensities. However, significantly more distance was covered in the first half compared to the second in medium intensities (11.1 - 19 km/h). The current findings provide a detailed description of the demands placed on elite soccer players, according to their positional role at different work intensities, which may be helpful in the development of individualized training programs.

Humans↗

Musical skill in dementia: a violinist presumed to have Alzheimer's disease learns to play a new song.

Previous studies have described patients with possible or probable Alzheimer's disease (AD) who continued to play familiar songs skillfully, despite their dementias. There are no reports about patients with dementia who successfully learned to play new songs, and two papers describe failures of patients with AD to learn to play a new song although they continued to play familiar songs competently. In the present paper we describe a moderately demented patient (SL) with probable AD who learned to play a song (Cossackaya!) on the violin that was published after the apparent onset of his dementia. He showed modest retention of the song at delays of 0 and 10 minutes. This contrasts with his profound disturbance in both recall and recognition on other anterograde memory tests (word lists, stories, figures, environmental sounds, sounds of musical instruments), and marked impairment on measures of remote memory (famous faces, autobiographical memory). SL showed milder deficits in confrontation naming, verbal fluency and attention, but no dyspraxia or aphasic comprehension deficits. Except for the Block Design test, his visuospatial skills were intact. SL's learning of the new song in the absence of any evidence of episodic memory is reminiscent of patients with temporal lobe amnesia who show better memory for song melody than for lyrics or verse, although his retention was not as good.

Aged↗

A comparison of physiological and anthropometric characteristics among playing positions in sub-elite rugby league players.

This study compared the physiological and anthropometric characteristics of specific playing positions and positional playing groups in sub-elite rugby league players. Altogether, 415 sub-elite rugby league players underwent measurements of standard anthropometry (body mass, height, sum of four skinfolds), muscular power (vertical jump), speed (10-m, 20-m, and 40-m sprint), agility ("L" run), and estimated maximal aerobic power (multi-stage fitness test). Props were significantly heavier and had a greater skinfold thickness than all other playing positions. Centres, fullbacks, and hookers were faster than props over 40 m. When the data were analysed according to positional commonality, props were taller, heavier, had a greater skinfold thickness, were less agile, and were slower over 10 m than all other positional groups. The hookers/halves and outside backs positional groups were significantly faster over 40 m than the backrowers and props positional groups. In addition, the hookers/halves and outside backs positional groups had significantly greater estimated maximal aerobic power than the props positional group. The results of this study demonstrate that few physiological and anthropometric differences exist among individual playing positions in sub-elite rugby league players, although props are taller, heavier, have greater skinfold thickness, slower 10-m and 40-m speed, less agility, and lower estimated maximal aerobic power than other positional groups. These findings provide normative data for sub-elite rugby league players competing in specific individual positions and positional playing groups.

Anthropometry↗

Why people continue to play online games: in search of critical design factors to increase customer loyalty to online contents.

As people increasingly play online games, numerous new features have been proposed to increase players' log-on time at online gaming sites. However, few studies have investigated why people continue to play certain online games or which design features are most closely related to the amount of time spent by players at particular online gaming sites. This study proposes a theoretical model using the concepts of customer loyalty, flow, personal interaction, and social interaction to explain why people continue to play online network games. The study then conducts a large-scale survey to validate the model. Finally, it analyzes current online games to identify design features that are closely related to the theoretical concepts. The results indicate that people continue to play online games if they have optimal experiences while playing the games. This optimal experience can be attained if the player has effective personal interaction with the system or pleasant social interactions with other people connected to the Internet. Personal interaction can be facilitated by providing appropriate goals, operators and feedback; social interaction can be facilitated through appropriate communication places and tools. This paper ends with the implications of applying the study results to other domains such as e-commerce and cyber communities.

Communication↗

Structures underpinning pretend play and word production in young hearing children and children with hearing loss.

Relationships between pretend play and word production were investigated in 10 hearing (H) and 10 toddlers with hearing loss (D) who attended an auditory/oral early intervention program. All children were videotaped interacting in free play with their hearing primary caregiver at 28, 29, and 30 months of age. Group comparisons were made for the scores for highest and mean levels of pretend play and for the underlying structures of decontextualization, decentration, sequencing, and planning. Relationships with word production were then explored for the two groups separately. Results showed significantly higher levels of pretend play for all dimensions for the hearing children and an association between level of pretend play and word production for the children with hearing loss. Associations between word production and sequencing and planning were found for both groups of children. Word production was associated with decontextualization for the hearing children and with decentration for the children with hearing loss. We discuss theoretical implications of the findings together with implications for intervention with toddlers who have hearing loss.

Journal Article↗

Returning to play: the mind does matter.

OBJECTIVE: The purpose of this article was to provide a brief historical perspective of the psychological factors that affect the potential for athletic injury, the psychological variables that affect recovery from injury, and the increasing pressure athletes face to return to play as soon as possible following an injury. DATA SOURCES/METHODS: A literature search was conducted using SportDiscus with keywords athlete, injury, sport psychology, and return to play. Further support for the literature cited and conclusions comes from more than 16 years of collegial consultations and direct clinical experience with multiple collegiate, Olympic, and professional sport organizations. RESULTS: Although the primary body of research regarding the psychological factors affecting sport injury and return to play is found in studies conducted in the 1980s, more recent research continues to support many of the original findings. Additionally, the applied experience of a full-time licensed and practicing sport psychologist is consistent with the early and subsequent research. CONCLUSIONS: Research, supported by applied experience, has resulted in the development of a set of causative psychological factors that increase the likelihood of sport injury, increase the potential recovery time from injury, and have thus far stood the test of time. One factor, however, that has changed over the years is the increasing pressure that elite athletes experience in returning to play much more quickly following an injury. Awareness of this increasing pressure is an important consideration for health care providers and sport organizations to ensure that athletes return medically and psychologically ready to play.

Adaptation, Psychological↗

Return to play following muscle strains.

OBJECTIVE: To assess return to play strategies following muscle strains with the desired outcomes of decreased competition play lost and minimized risk for recurrent injury. METHODS: Literature review of previous studies that examine return to play criteria for the commonly seen muscle strain injuries in sport. RESULTS: There have been no studies directly comparing different return to play approaches. Studies have instead concentrated on recurrence risk factors and prognosis assessment, particularly for hamstring injuries. There is some literature support for risk factors for recurrence such as persisting strength deficits, larger injuries seen on diagnostic imaging, players in high-risk positions or sports, inability to complete functional tasks without pain, and strains of specific high-risk muscles (biceps femoris, central tendon of rectus femoris, medial head of gastrocnemius, adductor longus or magnus). CONCLUSIONS: There are no consensus guidelines or agreed-upon criteria for safe return to sport following muscle strains that completely eliminate the risk for recurrence and maximize performance. At this time, it may be a sensible strategy to allow earlier return to play in team sports and accept a low to moderate injury recurrence rate. Improved prognostic assessment of muscle strains with injury identification (MRI) and injury assessment (isokinetic testing) may be assist practitioners to lower, but not eliminate, recurrent injuries.

Athletic Injuries↗