This study was performed to test the effect of EMG feedback training during the instep kick with dominant leg. Seventy-one male university soccer players performed the instep kicks. Trapezius activity was recorded. They were assigned with high-skilled (H) and low-skilled (L) players. Further their groups were assigned to three groups (feedback; FH, FL, no feedback; NFH, NFL, and Control; CH, CL). Feedback and no feedback groups participated in the dual task (kicking and EMG reduction) in which they were instructed to shoot correctly and to reduce their trapezius activity. EMG feedback based on trapezius activities, was visually presented only to feedback groups. Control groups performed only kicking tasks without EMG reduction. FH and FL groups reduced their trapezius activity and increased the probability of correct guessing about muscle tension. Also FH group increased the kick accuracy and converged the kicking form. The results indicated that EMG feedback training improved the ability of muscle regulation and muscle awareness. The results of this study were explained by the allocation of attentional resource. Our findings suggest that EMG feedback training improves kicking performances for the high-skilled players.

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Japanese people enjoy bathing, almost once a day. A large number of deaths while taking a bath at home are reported in Japan, and most of them are among the elderly and during the winter.
We measured physiological and psychological responses during bathing and found large variations in blood pressure and pulse rate when getting into and out of the bath. In our study, 10 young men (19-25 yrs.) took a bath under immersion of 38°C or 40°C warm water for 10 minutes. They were instructed to get into and out of the bath, rapidly or slowly.
When getting into the bath, the blood pressure rose and fell for a short time, and the pulse rate increased by less than 20 beat/min. The temperature of bath water and the speed of getting into the bath didn't affect these responses. When getting out of the bath after 10 min bathing, the blood pressure fell seriously and the pulse rate increased by more than 30 beat/min. The fall of the blood pressure was affected by the speed of getting out of the bath. When we compare taking a bath with 40°C warm water with 38 t water, the systolic blood pressure fell more seriously and the pulse rate increased less remarkably in the former. Since the pulse rate had already increased after taking a bath with 40°C warm water, we presumed that the pulse rate could not afford to increase for the behavior of getting out of the bath because of the subsequent serious systolic blood pressure drop.
In sum, large temporal variations in blood pressure and pulse rate will occur getting into and out of the bath. The systolic blood pressure seems to fall seriously when getting out of the bath after 10-min bathing with 40°C warm water. Accordingly, getting into and out of the bath in a rapid manner will evoke a serious flux in the blood pressure and thus getting into and out of the bath in a much slower manner is recommended in order to avoid such profound fluctuations.

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The present study examined the effects of predictability and controllability of aversive shocks on auditory N1-P2 vertex potentials and the amplitude of high-frequency component of heart rate variability as an index of cardiac parasympathetic tone. The experiment consisted of four periods : namely baseline period (tone stimuli alone); unpredictable-uncontrollable shock period (UP-UC) in which tone stimuli and shocks were randomly interspersed; predictable-uncontrollable shock period (P-UC) in which occurrences of shock was predicted by tone stimuli; and predictable-controllable shock period (P-C) in which the tone signaled the opportunity to avoid the shock. The experimental data (n=34) were examined in reference to those obtained from the control group (n=13) who underwent tone alone without shocks. The Ni amplitude increased during P-UC period, whereas the P2 amplitude was enhanced during P-C period. In addition, the lowest subjective rating of the stress was observed during P-C period. These results suggested that subjects used different information-seeking strategies in relation to various stressful situations. The consistent result was not found between subjective rating of the stress and cardiac parasympathetic tone.

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Stolz & Besner (1998) reported that there are two possible loci, morphological (i. e., letter and word) and semantic levels, for semantic priming in the interactive activation framework. To investigate the relation between levels of processing in Kanji recognition and the loci where the semantic priming occurs, event-related brain potentials (ERPs) to Kanji characters were recorded in two task conditions of semantic matching and non-task. The stimuli were presented in AAAAABAA form (habituation paradigm), and the repetition Kanji A and test Kanji B were semantically related, unrelated, or identical. In the non-task condition, the semantic priming effect was ob-served in a positive wave with a 200-ms peak latency, P200 (P2); the recovery of P200 amplitude was reduced for the semantically related test Kanji characters, compared with the unrelated ones. In the semantic matching task, where the subjects were required to decide whether or not the repetition and test Kanji characters were semantically related, the priming effect was obtained as the attenuation of the later negative wave N310 (corresponding to N400) for the related test Kanji, instead of P200. The P200 priming effect was interpreted as the semantically related response at the morphological level, which was due to semantic-level activation feeding back to the corresponding morphological-level representation, whereas the N310 effect as a reflection of the semanticlevel activation of the semantic associates with the preceding Kanji. The task dependency of semantic priming levels indicated the top-down control in Kanji recognition processes.

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The effects of sleep-onset REM periods (SOREMP) and NREM periods (stage 2) on sleepiness and fatigue were examined using 14 normal participants. Either a SOREMP or NREM episode was induced after sleep interruption using the Sleep Interruption Technique. Participants assessed their subjective sleepiness and fatigue before and after these sleep episodes using the Kwansei-gakuin Sleepiness Scale (KSS) and the Fatigue complaints test by The Industrial Fatigue Research Committee of the Japan Association of Industrial Health. The results showed that KSS scores before SOREMP episodes were higher than those in NREM episodes. More complaints such as “yawny”, “sleepy”, “want to lie down to sleep” were obtained both before and after SOREMP episodes than before and after NREM episodes. On the other hand, more complaints such as “twitching of the eyelid and/or fa-cial muscle” after NREM episodes were obtained than after SOREMP. We discuss the contribution of physiological factors such as EOG, EMG and the circadian rhythm to the relationship between SOREMP and subjective sleepiness and fatigue.

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P3 (P300) event-related brain potential (ERP) during the auditory oddball paradigm of passive condition (passive P3) was compared with the P3 during an active condition (active P3). In our previous study (Miyajima & Era, 1999), passive P3 did not appear with an infrequent-stimulus probability of 0.20 on 500/3000 Hz tone sequences. The present study was aimed to determine if passive P3 was elicited by reducing the infrequent-stimulus probability to 0.10. P3 responses were recorded from the subjects under both the passive condition and the active discrimination condition. The infrequent stimulus in the passive condition elicited a P3 component with the similar scalp distribution and latency to those from the active condition. These findings support that stimulus probability contributes to P3 generation in the passive oddball paradigm, and suggest that task relevance is related to P3 amplitude but not to P3 latency.

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