Evaluation of compatibility effects in the precuing of arm and direction parameters

The present study evaluated the role of compatibility effects in the precuing of arm and direction parameters. In the first two experiments different stimulus and response arrangements were examined. For all three experiments the spatial precue and imperative stimuli were compatibly assigned to responses (i.e., a direct correspondence existed between the stimulus and response locations). Experiments 1 and 2 indirectly tested the effect of decision processes required by the stimulus-response set. Experiment 1 replicated previous research that has found longer reaction times for the direction uncertain parameter as compared to arm uncertain. Experiment 2 examined the precuing of arm and direction parameters with stimuli that maintained right-left arrangements for both parameters. Unlike Experiment 1, reaction times did not differ for precuing the two movement parameters. Experiment 3 directly examined the effect of differential decision requirements from up-down spatial stimuli and right-left spatial stimuli for a single parameter. In support of results from the first two experiments, results indicated longer reaction times for decisions from up-down stimuli as compared to right-left stimuli. Because reaction times for precued movement parameters are a function of the stimulus and response arrangements used, differences in reaction times are most likely due to compatibility effects arising from differences in the spatial arrangements of the precued stimulus and response set.     

Neuromuscular, metabolic and hormonal profiles of young tennis players and untrained boys

This study compared the neuromuscular, metabolic and hormonal profiles of trained prepubescent tennis players and an untrained group. The boys in the experimental group (n = 9; mean age +/- S.D. = 11.4 +/- 0.5 years) had participated in tennis training for 2.3 +/- 1.0 years and the boys in the control group (n = 9; mean age +/- S.D. = 10.9 +/- 0.4 years) were normal active volunteers. The tennis players were found to be physically more active than the controls when the comparison was made for either 1 year (4.9 +/- 1.8 vs 2.6 +/- 2.5 times per week; P less than 0.05) or for 1 week (3.4 +/- 1.2 vs 0.4 +/- 0.5 times; P less than 0.001) preceding the tests. Choice reaction time was significantly (P less than 0.01) shorter in the experimental group (258 +/- 16 ms) than in the control group (344 +/- 81 ms). Dropping height in the best drop jump was significantly (P less than 0.05) higher in the tennis players (0.46 +/- 0.19 m) than in the control boys (0.27 +/- 0.10 m). The tennis players had significantly lower oxygen consumption at the 'anaerobic threshold' than the controls (P less than 0.05). There were no significant differences between the groups in serum hormone levels. The small differences that existed may have been caused by active participation in sport by the tennis players.