ABSTRACT
Objective: To investigate the characteristics of attentional bias in emotional faces of policemen with different trait anxiety levels. Methods: By using the State-Trait Anxiety Inventory (STAI), 44 policemen (23 males and 21 females) were included in the higher trait anxiety level group and 44 policemen (25 males and 19 females) were included in the lower trait anxiety level group. The 2 anxiety style ((higher trait anxiety level, lower trait anxiety level) × 2 emotional type (positive, negative) × 2 clue type (identical side, opposite side) hybrid design was used to investigate the attentional bias of the response time differences between the two groups of policemen on keystroke responses of different emotional types and different types of clues by using a dot probe. Results: The positive emotional face reaction of the higher trait anxiety level group was less than that of the negative emotional face reaction[ (638. 0 ± 12. 4) ms vs. (651. 7 ± 13. 1) ms, P ＜ 0. 01], while the lower trait anxiety level police had no statistical significance on the reaction of positive emotional face and negative emotional face (P＞ 0. 05). The clue types in the higher trait anxiety level group were identical side less than opposite side response time [ (640. 3 ± 12. 6) ms vs. (649. 5 ± 13. 0) ms, P ＜ 0. 05], and there was no statistical significance in the lower trait anxiety level group about identical side and opposite side response time (P＞ 0. 05). The clue type in identical side, there was no significant difference in the response of two groups to positive emotional faces and negative emotional faces (P＞ 0. 05); while the clue type in opposite side, the response of higher trait anxiety level group to negative emotional faces was higher than that of positive emotional faces [ (663. 1 ± 9. 8) ms vs. (651. 4 ± 8. 9) ms, P ＜ 0. 05]. Conclusion: It suggests that the policemen with higher level of trait anxiety have selective attentional bias to negative emotional faces, which induced by impaired attentional disengagement.
ABSTRACT
BACKGROUND: Exercise preconditioning can lighten exercise-induced muscle damage, thereby to avoid delayed onset muscle soreness. At present, experimental research is scarce that apply intedeukin-6 (IL-6), creatine kinase (CK) and creatine kinase isoenzyme (CK-MM) to evaluate skeletal muscle damage.OBJECTIVE: To observe the effects of exercise precondiUoning on muscle damage at different phases after eccentric exercise and changes of blood IL-6, CK and CK-MM.DESIGN, TIME AND SETTING: The randomized control animal expedmant was carded out in the Animal Laboratory of Chengdu Sports University between 2006 and 2007. MATERIALS: Eighty female adult SD rats, weighing (231.3+12.44) g, were adopted. Eighty rats were randomly divided into without exercise preconditioning group (n=40) and exercise preconditioning group (n=40). Each group was assigned into 5 subsets, termed before exercise, immediately after exercise, 24, 48, 72 hours after exercise, with 8 rats in each subset. METHODS: Except before exercise subset, other rats in the without exercise preconditioning group were forced to do treadmill exercise (19-21 m/min, -16° incline, 90 minutes). All rats of exercise preconditioning group were forced to do eccentric treadmill exercise for two weeks. After two weeks, treadmill test was made for rats except before exercise subset. MAIN OUTCOME MEASURES: Soleus muscle structure, blood IL-6, CK and CK-MM immediately, 24, 48, 72 hours after eccentric exercise.RESULTS: The soleus muscle was damaged after exercise, especially in without exercise preconditioning group at 24-48 hours after exercise. Blood IL-6 of without exercise preconditioning group increased significantly immediately after exercise and then gradually decreased, but again raised at 72 hours after exercise. In the exercise preconditioning group, blood IL-6 slightly reduced immediately after exercise and then gradually increased. Peak value appeared at 48 hours. After exercise, IL-6 of exercise preconditioning group was obviously lower than that of without exercise preconditioning group. Before exercise, serum CK and CK-MM of exercise preconditioning group were less than that of without exercise preconditioning group. After exercise, the CK and CK-MM were firstly raised and then reduced in two groups. Except 72 hours after exercise subset, the variation of CK and CK-MM of exercise preconditioning group was lower than that of without of exercise preconditioning group. CONCLUSION: Exercise preconditioning is redounded to lighten the ultrastructure injury of skeletal muscle induced by eccentric exercise and blood indices changes induced by exercise stress. The individual variation of CK and CK-MM is so tremendous that they fit the comparison of intrasubject variability.