auditory stimuli between simple and choice RT tasks. For instance, Kida et al. (2005) reported that baseball experts had shorter RTs than tennis players and nonathletes in a Go/Nogo RT task but not in a simple RT task. Blind individuals also showed superior auditory choice RTs compared with sighted individuals in a divided attention task (Kujala et al. 1997) and a spatial attention task (Chen et al. 2006). Moreover, early-blind individuals had shorter RTs than sighted individuals in selective attention tasks, but not in a simple RT task, indicating enhanced attentional performance in early-blind individuals (Collignon and De Volder, 2009; Collignon et al. 2006). Based on previous studies, it was assumed that blind footballers with visual impairments would have shorter auditory choice RTs than sighted nonathletes. Given the superiority of blind footballers in choice RT tasks, it should be determined whether their shorter choice RTs are due to rapid identification of sound direction or faster processing of auditory input and motor output. However, it remains unknown whether blind footballers have shorter auditory simple RTs and choice RTs than sighted athletes, who are required to produce a faster response largely in the visual modality. Taken together, the present study aimed to compare simple RT, choice RT, and response accuracy among blind footballers, sighted footballers, and nonathletes. We hypothesized that blind footballers would have shorter RTs than sighted footballers in the choice RT tasks, but not in the simple RT task. We also hypothesized that blind footballers would show higher overall response accuracy and less front-back confusion. Methods Participants Participants were blind footballers (n = 10; mean age = 27.6 ± 5.3 years; playing experience = 8.0 ± 4.2 years), sighted college footballers (n = 11; mean age = 19.2 ± 1.2 years; playing experience = 12.4 ± 2.2 years), and healthy sighted nonathletes (n = 11; mean age = 22.7 ± 2.9 years; no regular exercise or training), based on the experimental design of the previous study (Campayo-Pierna et al. 2017). The sample size was based on an a priori power analysis for the within-between interaction in a repeated measures ANOVA (estimated effect size of f = .25, α =.

The purpose of this study was to establish the asymmetry and body wave characteristics related to shoulder, hip, knee, and ankle roll in unilateral arm amputee swimmers. Three unilateral arm amputee swimmers, including one Paralympic medallist (swimmer A), volunteered in this study. They conducted two 10-15s front crawl tests with sub-maximum and maximum speeds in a flume. Shoulder, hip, knee, and ankle roll amplitude and progression of a torsional body wave was quantified using a motion capture system and a Fourier analysis. Swimmer A showed 50% higher stroke frequency than the other swimmers. Swimmers achieved larger shoulder roll amplitude toward the affected than the unaffected side by 19-89%. Swimmer A showed body wave velocity slowing down when it travelled caudally, while national level swimmers presented increasing wave velocity, suggesting that swimmer A had a less effective kicking than the other swimmers. In conclusion, the technique of the unilateral arm amputee swimmers was characterised by a large shoulder roll angle toward the affected side. The Paralympic medallist had larger shoulder roll asymmetry and less effective kicking than the other swimmers and yet achieved higher swimming speed because of his high stroke frequency.

The mechanical parameters of keyboard switches affect the psychological sense of pressing. The effects of different mechanical parameters on psychological sense have been quantified using questionnaires, but these subjective evaluations are unable to fully clarify the modulation of information processing in the brain due to these differences. This study aimed to elucidate the ability of electroencephalography (EEG) measurements to detect the modulation of subconscious information processing according to mechanical parameter values. To this end, we prepared five mechanical switches with linearly increasing values of pretravel (PT: the distance from the free position until the operating position). We hypothesized that the differences in PTs would subconsciously affect the motor preparation prior to pressing switches because switches with PTs that deviated from those commonly used were predicted to increase the users' attention level when pressing. Differences in motor preparation were quantified using the mean amplitudes of the late contingent negative variation (CNV). We recorded EEGs of 25 gamers during a reaction task for fast switch pressing after a response cue preceded by a pre-cue for response preparation; we also measured the reaction time feedback on each switch pressing trial. Participants performed five sessions (60 trials per session) in total. For the analysis, trials were divided into first (session 1, 2, and 3) and second half sessions (session 4 and 5). In the latter session, CNV amplitudes were significantly higher for the switch with the highest PT than for that with a medium PT, which is closest to that commonly used in commercial mechanical switches. On the other hand, the questionnaire did not detect any significant differences between PTs in their subjective rankings of the psychological effects of switch pressing. These results suggest that differences in PTs modulate motor preparation to press switches, and that EEG measurements may provide a novel objective evaluation of the mechanical parameters of keyboard switches.

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