During competition athletes ard significantly affected by psychological factors such as selfconfidence, arousal, attention, visualization, motivation, attitude. These psychological capabilities, called mental skills, can be successfully controlled through systematic mental skill training. The focus of mental skill training is to perform consistently to athlete` s potential. The corrent study reviewed literature on mental skills which are essential in consistent sport performance. Most of mental training programs (e. g. . Unestalhl`s, Nideffer`s, and Loehr`s model) are self-instructional and convenient to use. However, to guarantee the enhancement of sport performance both right timing of mental trainging and athletes; receptivity should be considered. Several studies on special target groups showed that mental training is a good solution to psychosomatic problems as well as ideal sport performance. In this context, research trends toward mental skills for sport and life suggests important implications to sport psychologist.

Psychological Refractory Period (PRP) is the delay in the response to the second of two closely spaced stimuli. This study was examined to find out the effects of inter-stimulus intervals and number of alternatives on PRP. Subjects were 5 female students who participated in experiment voluntarily. Experimental task was double-stimulus task which first task was button pressing and second task was target aiming. Results showed that inter-stimulus interval influences on PRP, and number of alternatives does influence on PRP.

The purpose of this study was to find the effect of the two different types of movement velocity control on timing variability and temporal structure parameters (time to peak positive acceleration, duration of positive acceleration, peak positive acceleration) of acceleration-time function. Subjects were 6 male students, and task was arm flexion movement. The results showed that when movement distance increased with movement time fixed, timing variability was constant, also time to peak positive acceleration and duration of positive acceleration were constant, but peak positive acceleration increased with statistical significance. And when movement time increased with movement distance fixed, timing variability increased, and time to peak positive acceleration, duration of positive acceleration increased, but peak positive acceleration decreased. The results suggest that each control types of movement velocity are different fundamentally, and movement velocity as a function of movement distance is achieved by the increase of peak positive acceleration with time to positive acceleration and duration of positive acceleration constant. Namely, this type of velocity is modulated by the change of force with phasing of generalized motor program, and movement velocity as a function of movement time is achieved by the extension of time to peak positive acceleration and duration of positive acceleration, Thus, this type of movement velocity is modulated by the change of phasing and relative force generalized motor program.

There have been increasing efforts to find the source of motor response error variability and to apply this information for the efficiency of human activity in real life. The purpose of this study was to examine of movement amplitude and movement time, and movement velocity on the space-timing variability. Subjects(6 male student) engaged in an angular timing task at four different movement times(150, 200, 250 and 300 msec) over four movement ranges, respectively, Movement velocity were 50, 120, 180, 240, 300, 400 deg/sec. The result indicated that first, spatial variability increased and timing variability decreased as amplitude increased in all movement times, but spatial variability decreased and timing variability increased as movement time increased in all movement amplitude. Spatial variability was changed linearly with increment of movement amplitudes and movement times, and timing variability was changed linearly with increment of movement amplitude. But timing variability was changed curvilinearly with increment of movement time. Second, spatial variability increased and timing variability decreased as movemnt velocity increased, and response variability changed curvilinearly with increment of velocity. These results suggest that movement amplitude, movement time and movement velocity are parameters of response variability.

The purpose of this study was to investigate the effect of change of force and response time to peak force on the forcee variability. The subjects were six male students in the department of physical education at seoul national university. They pulled the immobale handle at the three change of force(30, 60, 90%) and three response time conditions(100, 300, 500ms) . A three by three(change of force by response time to peak force) factorial analysis of variance with repeated measures used to dertermine whether or not the effect on the force variability was significant (P< .0l) . The results obtained from the data analysis were follows First, there was significant difference of change of force in the force variability. Second, there was have no significant difference of response time to peak force in the force variability. Third, there was have no significant difference of the relation change of force and response time to peak force variabiliyty.

Most movements executed in sport performance and everyday life are aimed at visual objects and are controlled visually. The role of visual feedback in control of movements has been a central issue in the study of motor behavior since Woodworth`s research in 1899. The time required to identify, decide, and initiate within-movement corrections based upon visual feedback has been called visual feedback processing time. The estimated visual processing time in most early experiments is about 250-300msec. However, there have been several evidences suggesting that visual feedback could be processed and used in lesser time. The evidences for faster visual processing time comes from the selective exclusion of visual feedback, the control of saccadic eye movement, and the analysis of movement trajectory. These experiments estimated that the visual processing time is about 120msec or less.