Coping skills of olympic developmental soccer athletes.

Athletes at Olympic Developmental Program (ODP) camps experience unusually high levels of expectations and inherent mental and physical challenges within such a short span of time. With the increasing emphasis on talent development, there has been consensus by the ODP staff to more clearly define present levels of coping skills, in order to enhance athletic prediction, maximize training efforts, identify the predisposition to injury, and focus on areas pertinent to successful performance. This study examined athletic and pain coping skills of U. S. ODP soccer athletes not previously investigated. Following written informed consent, 70 males completed the Athletic Coping Skills Inventory and the Sports Inventory for Pain. Data were analyzed by competitive level (U-14, U-15), and skill position (goalkeeper/defense, midfield/foward). MANOVA indicated a significant main effect across competitive level (Wilks' Lambda F(12,57) = 2.27; p = 0.02; n-beta = 0.915) but no significant effect by skill position (Wilks' Lambda F(12,57) = 0.931; p = 0.523; n-beta = 0.457). Post hoc analyses indicated that U-15 athletes scored significantly higher in concentration (p = 0.01) and body awareness (p = 0.03), but lower in avoidance (p = 0.01) than U-14 competitors. In conclusion, older, more experienced athletes revealed more positive athletic and pain coping skills than younger, less experienced athletes, although athletes in skill positions requiring spontaneous decision-making skills and split-second adjustment in a constantly changing sport environment (forwards, midfielders) did not exhibit more positive athletic and pain coping skills than those positions requiring reaction and protection (defenders, goalkeepers).

Dietary administration of nickel: effects on behavior and metallothionein levels.

Adult male rats were fed either 0, 10, or 20 mg Ni/kg body weight (as NiCl2) via a 10 g daily food ration. Following 14 days of exposure, animals were trained over a period of 61 days to lever press for food on a VI-2 operant training schedule while continuing to experience the indicated daily doses. Those rats treated with 20 mg/kg Ni lever pressed at a significantly lower rate than controls. Group 10 mg/kg subjects were not significantly different on this behavioral measure than control subjects. Atomic absorption spectrophotometric analysis revealed a dose/response accumulation of Ni in the kidney, but analyses of blood, bone, brain, hair, small intestine, liver, and testes did not show differential agent accumulations. Neither hepatic nor renal metallothionein levels were increased above control levels. These findings were discussed within the framework of other recent behavioral and biochemical studies of heavy metal toxicity.

Effects of acute trimethyltin exposure on appetitive acquisition and extinction performance in the adult rat.

Adult male rats were given one intragastric infusion of either 7 mg/kg trimethyltin chloride (dose calculated as the base of trimethyltin [TMT]) or physiological saline. Twenty-one days after dosing, subjects from each condition were divided into two equal-sized groups and trained with either partial (PRF) or continuous (CRF) reinforcement in a straight alley maze. The acquisition phase of training, lasting 40 trials (4 trials/day), was followed by 20 trials of extinction training (4 trials/day). Analyses performed on total speed revealed that TMT-treated subjects performed at lower levels during acquisition than controls regardless of schedule condition. Also, the rate of resistance to extinction was significantly reduced for treated subjects compared with that of controls regardless of the training schedules used during acquisition. A partial reinforcement extinction effect was observed for both control and TMT-treated subjects, that is, independent of dose regimen; PRF training occasioned greater persistence during extinction than did CRF training. These findings are discussed in terms of their implications for contemporary empirical and theoretical issues relating to TMT-induced hippocampal lesions.

The effects of oral cadmium exposure on passive avoidance performance in the adult rat.

Step-down passive avoidance acquisition and 24 h retention performance were examined in adult rats given daily doses of either 0, 1, or 5 mg/kg cadmium (Cd) (as CdCl2) via the diet. Results indicated that subjects exposed to the 5 mg/kg Cd diet were less likely to step off a safe platform onto an electrified grid floor than controls. The 1 mg/kg subjects did not differ from controls on this acquisition task. None of the groups showed differential performances on a retention test administered 24 h after acquisition training. These results are discussed in terms of recent claims that Cd exposure enhances emotional reactivity in animals.

Behavioral effects of chronic lead exposure in the adult rat.

Adult rats fed daily rations of laboratory chow laced with lead acetate, were tested for operant (schedule-controlled) responding and conditioned suppression. In Experiment 1, animals receiving 10 mg/kg lead showed significantly lower operant response rates (lever pressing) than controls. Conditioned suppression performance was not different between the two groups. During retraining that followed a 42 day no-training period, lead-treated subjects showed greater percent of prior baseline responding than controls. The groups were not different on a test for stimulus control or an appetitive resistance to extinction test. In Experiment 2, separate lead-treated groups were chronically exposed to either 10 mg/kg, 5 mg/kg, or 1 mg/kg lead daily. Behavioral tests showed that while the lowest lead level (1 mg/kg) occasioned higher rates of operant lever pressing relative to controls, the highest level (10 mg/kg) again produced lower rates. On a retraining task administered after an interpolated 90 day no-training period, the two highest exposure groups were significantly above controls regarding percent of baseline responding and there was evidence that the 5 mg/kg group was significantly superior to controls in terms of absolute response rate. No differences in conditioned suppression or resistance to extinction were observed in the second experiment.

The effects of chronic cadmium exposure on schedule controlled responding and conditioned suppression in the adult rat.

Adult rats fed daily rations of laboratory chow with added CdCl2 were tested for schedule controlled responding and conditioned suppression (conditioned emotional response-CER). Determinations of tissue Cd, levels of metallothionein, and the ratio of Cd in the tissue to the Cd-binding capacity of metallothionein also were made. Animals were exposed daily to either 5 mg/kg Cd (Group Cd-5), 1 mg/kg Cd (Group Cd-1), or no Cd (Group Control). An initial phase of training on a variable interval 2 min (VI-2) food reinforcement schedule lasting 40 sessions (1 session/day) was followed by CER training and then an interpolated period (100 days) of continued exposure but with no training. Schedule retraining was introduced for 21 sessions (1 session/day). The results showed no group differences during original schedule training. On the CER test, Group Cd-1 was found to exhibit less suppression (defined in terms of lever press rates) than controls to preaversive stimuli. Group Cd-5 showed significantly greater suppression to the primary aversive stimulus (shock) than the other two groups. Both treatment groups showed significantly lower lever press rates than controls on the schedule retraining task. These behavioral disturbances occurred commensurate with increases in non-metallothionein bound Cd in the liver, kidney, and small intestine.

The effects of chronic cobalt exposure on behavior and metallothionein levels in the adult rat.

Adult rats fed daily rations of laboratory chow laced with cobalt chloride were tested for operant (schedule-controlled) responding and conditioned suppression (CER). Animals exposed to 20 mg/kg Co, but not animals exposed to 5 mg/kg Co, lever pressed at a significantly slower rate than nontreated control subjects over the last 8 sessions of a 35 session operant training phase (1 session/day). Control and treatment subjects did not show significantly different CER performances. Nor were significant differences found on a test of mixed VI-2, DRO responding where subjects were required to lever press for reward during the first 15 min component and not lever press during the last 15 min component of the schedule. Testicular atrophy was evident among subjects exposed to 20 mg/kg Co. Atomic absorption spectrophotometric analyses revealed a dose-response effect regarding tissue accumulations of Co in blood, bone, brain, hair, small intestine, kidney, liver, and testes. Contrary to the biochemical pattern shown by some other heavy metals, prolonged Co exposure did not induce significant increases in metallothionein concentrations in the liver, kidney, or small intestine.

Conditioned suppression in the adult rat following chronic exposure to lead.

Conditioned suppression was examined for control (N = 8) and lead-treated (N = 8) adult rats. Treated animals were exposed daily to 10 mg/kg lead administered via the diet as lead acetate. 40 days of operant lever press training on a multiple schedule using food as reward was given. Lever press training continued for an additional 5 days but during this period subjects experienced superimposed 3 min tone presentations followed by electric shock (1.3 mA, 1.5 s duration) to a grid floor. Tone presentations were observed to be significantly more disruptive of operant steady state responding for treated subjects as compared to controls. This finding supports earlier claims that lead exposure enhances emotionality.

Locus of control, learned helplessness, and control of heart rate using biofeedback.

Subjects were 24 male undergraduate students. False biofeedback was provided to give the impression of success or failure (helplessness) on a preliminary task. Authentic biofeedback was then provided for control of heart rate. Subjects were administered pre- and post-locus of control scales using Levenson's multidimensional scales. A significant relationship between locus of control and success or failure conditions added validity to Levenson's approach. Results and future research are discussed.