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To further develop three-dimensional (3D) applications, it is important to elucidate the negative effects of 3D applications on the human body and mind. Thus, this study investigated differences in the effects of visual fatigue on cognition and brain activity using visual and auditory tasks induced by watching a 1-h movie in two dimensions (2D) and 3D. Eighteen young men participated in this study. Two conditions were randomly performed for each participant on different days, namely, watching the 1-h movie on television in 2D (control condition) and 3D (3D condition). Before and after watching the 1-h movie on television, critical flicker fusion frequency (CFF: an index of visual fatigue), and response accuracy and reaction time for the cognitive tasks were determined. Brain activity during the cognitive tasks was evaluated using a multi-channel near-infrared spectroscopy system. In contrast to the control condition, the decreased CFF, and the lengthened reaction time and the decreased activity around the right primary somatosensory cortex during Go/NoGo blocks in the visual task at post-viewing in the 3D condition were significant, with significant repeated measures correlations among them. Meanwhile, in the auditory task, the changes in cognitive performance and brain activity during the Go/NoGo blocks were not significant in the 3D condition. These results suggest that the failure or delay in the transmission of visual information to the primary somatosensory cortex due to visual fatigue induced by watching a 3D movie reduced the brain activity around the primary somatosensory cortex, resulting in poor cognitive performance for the visual task. This suggests that performing tasks that require visual information, such as running in the dark or driving a car, immediately after using a 3D application, may create unexpected risks in our lives. Thus, the findings of this study will help outlining precautions for the use of 3D applications.

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The study aimed to investigate the effects of kinesthetic experiences on balance ability (using exercise balls for gymnastics) and on interpersonal relationships by comparing two different learning methods. Participants learning gymnastics during physical education classes at university were randomly allocated to a kinesthetic-experiential learning (KEL) group (n = 20) or a model-mastery learning (MML) group (n = 22). Both groups practiced a balancing exercise on an exercise ball. In the KEL group, participants were asked to pay attention to the sensations of their body on the ball in a variety of movements, whereas the MML group was asked to reproduce the instructions of the ideal model provided by an instructor. The results showed that the participants in the KEL group had longer balancing time on the exercise ball, higher self-evaluation scores, and higher interpersonal relationship scores than those in the MML group, although the objective evaluations of postural stability were better in the MML group than in the KEL group. These findings suggest that methods that provide learners with versatile kinesthetic experiences through a variety of movements are more effective for enhancing balance ability and interpersonal relationships.

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The purpose of the present study was to compare learners' movement variability while maintaining balance and the ability to recover balance using the kinesthetic-experiential learning (KEL) method of implicit learning and the model-mastery learning (MML) method of explicit learning. The participants were 29 healthy university students. They were randomly divided into two groups (KEL and MML). They were required to balance both knees on an exercise ball. The balancing time and the ability to recover their balance were measured using motion capture. Results indicated that balancing time was significantly improved for both learning methods. Regarding the learners' movements while maintaining balance, they maintained balance while moving in the KEL method, whereas they maintained balance by keeping the entire body stationary in the MML method. Concerning the ability to recover, the KEL method improved the balance recovery ability more effectively than the MML method. Therefore, we concluded that using the KEL method at the initial stage of learning improves learners' balance recovery ability and increases movement variability.

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In blind football, players predict the sound location of a ball to underpin the success of ball trapping. It is currently unknown whether blind footballers use head movements as a strategy for trapping a moving ball. This study investigated characteristics of head rotations in blind footballers during ball trapping compared to sighted nonathletes. Participants performed trapping an approaching ball using their right foot. Head and trunk rotation angles in the sagittal plane, and head rotation angles in the horizontal plane were measured during ball trapping. The blind footballers showed a larger downward head rotation angle, as well as higher performance at the time of ball trapping than did the sighted nonathletes. However, no significant differences between the groups were found with regards to the horizontal head rotation angle and the downward trunk rotation angle. The blind footballers consistently showed a larger relative angle of downward head rotation from an early time point after ball launching to the moment of ball trapping. These results suggest that blind footballers couple downward head rotation with the movement of an approaching ball, to ensure that the ball is kept in a consistent egocentric direction relative to the head throughout ball trapping.

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Earlier studies have demonstrated that blind footballers are more accurate in identifying sound direction with less front-back confusion than sighted and blind non-football playing individuals. However, it is unknown whether blind footballers are faster than sighted footballers and nonathletes in identifying sound direction using auditory cues. Here, the present study aimed to investigate the auditory reaction times (RTs) and response accuracy of blind footballers during auditory RT tasks, including the identification of sound direction. Participants executed goal-directed stepping towards the loudspeaker as quickly and accurately as possible after identifying the sound direction. Simple, two-choice, and four-choice auditory RT tasks were completed. The results revealed that blind footballers had shorter RTs than sighted footballers in the choice RT tasks, but not in the simple RT task. These findings suggest that blind footballers are faster in identifying sound direction based on auditory cues, which is an essential perceptual-cognitive skill specific to blind football.

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The purpose of the present study was to examine whether the fixation distance in real three-dimensional space affects manual reaction time to peripheral visual stimuli. Light-emitting diodes were used for presenting a fixation point and four peripheral visual stimuli. The visual stimuli were located at a distance of 45cm and at 25° in the left, right, upper, and lower directions from the sagittal axis including the fixation point. Near (30cm), Middle (45cm), Far (90cm), and Very Far (300cm) fixation distance conditions were used. When one of the four visual stimuli was randomly illuminated, the participants released a button as quickly as possible. Results showed that overall peripheral reaction time decreased as the fixation distance increased. The significant interaction between fixation distance and stimulus location indicated that the effect of fixation distance on reaction time was observed at the left, right, and upper locations but not at the lower location. These results suggest that fixating at far distance would contribute to faster reaction and that the effect is specific to locations in the peripheral visual field. The present findings are discussed in terms of viewer-centered representation, the focus of attention in depth, and visual field asymmetry related to neurological and psychological aspects.

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The present study examined the influence of attentional focus on performance during a long-distance throwing task. Twelve participants executed three maximum-effort, long-distance baseball throwing attempts in three focus conditions: internal focus on wrist flexion (wrist internal focus), internal focus on the separation between pelvis and upper torso orientations (torso internal focus), and external focus on the ball path (external focus). Compared with the external focus and torso internal focus conditions, performance was poorer in the wrist internal focus condition. Performances were not different in the torso internal and external focus conditions. In addition, attentional focus affected the release angle of the ball but not its initial velocity. Our results reveal that the body part targeted for internal focus of attention and the forcefulness of the motor activity can be as important to motor performance as whether the attention is internal or external.

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Recently, we proposed that strenuous exercise impairs peripheral visual perception because visual responses to peripheral visual stimuli were slowed during strenuous exercise. However, this proposal was challenged because strenuous exercise is also likely to affect the brain network underlying motor responses. The purpose of the current study was to resolve this issue. Fourteen participants performed a visual reaction-time (RT) task at rest and while exercising at 50% (moderate) and 75% (strenuous) peak oxygen uptake. Visual stimuli were randomly presented at different distances from fixation in two task conditions: the Central condition (2° or 5° from fixation) and the Peripheral condition (30° or 50° from fixation). We defined premotor time as the time between stimulus onset and the motor response, as determined using electromyographic recordings. In the Central condition, premotor time did not change during moderate (167±19ms) and strenuous (168±24ms) exercise from that at rest (164±17ms). In the Peripheral condition, premotor time significantly increased during moderate (181±18ms, P<0.05) and strenuous exercise (189±23ms, P<0.001) from that at rest (173±17ms). These results suggest that increases in Premotor Time to the peripheral visual stimuli did not result from an impaired motor-response network, but rather from impaired peripheral visual perception. We conclude that slowed response to peripheral visual stimuli during strenuous exercise primarily results from impaired visual perception of the periphery.

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When individuals attempt to walk through the center of a doorway (i.e., spatial bisection), the body's midpoint at crossing can deviate from its true center. Such deviation could result from asymmetry in spatial cognition. However, previous studies failed to find a significant correlation between bisection performance during walking and that during line/spatial bisection. We investigated whether such failure would result from different effectors being used for bisection (i.e., body midpoint or finger/laser pointer). We also investigated whether the difference in an individual's eye dominance would affect the relationship. Thirty-two young adults (16 of them with right-eye dominance) participated. For a walking task, participants walked through the perceived center of a wide doorway. For a spatial bisection task, they observed the same doorway under two distance conditions (about 0.5 and 2 m) and aligned their body midpoint with the perceived center in the sagittal dimension. Both tasks were performed under three visual occlusion conditions (dominant eye, non-dominant eye, and no occlusion). The results showed that, for the spatial bisection task, occluding the dominant eye caused deviation of the bisected point to the contralateral side. However, for the walking task, such an effect was observed only in participants with a dominant right eye. Consequently, directional biases in both tasks were significantly correlated only for right-eye-dominant participants. These results suggest that, for right-eye-dominant individuals only, use of the same effector for both tasks showed a clear relationship between the two tasks. Possible explanations for these findings were discussed.

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PURPOSE: Previous research has indicated that older adults have significantly lower accuracy in terms of force control than young adults. In addition, accuracy of force control is known to decrease in the absence of visual feedback. However, whether the effect of visual feedback on fine motor control is similar for young adults and older adults is not clear. The purpose of this study, therefore, was to examine the effect of visual feedback on bimanual pinch force control in older adults. METHODS: Thirty-one undergraduate students (age 19.7 ± 0.9 years) and 31 older adults (age 65.1 ± 8.1 years) participated in this study. After measuring finger-pinch maximal voluntary force (MVF), the participants were asked to maintain 10% MVF as steadily as possible in two different conditions: with visual feedback (visual feedback condition; VF condition) and without visual feedback (no visual feedback condition; NVF condition). RESULTS: We found that older adults had significantly greater targeting error and force variability than young adults in the VF condition, but not in the NVF condition. In addition, older participants exhibited a significantly greater sum of power for the 0-4 and 4-8 Hz frequency bin than young adults (p < 0.05) in the VF condition, although there was no significant difference in the NVF condition. CONCLUSIONS: These results suggest that older adults do not use visual information as effectively as younger adults to reduce force control error.

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Basketball players have to move laterally and quickly change their movement directions, especially during defensive moves. This study aimed to investigate how frontal and sagittal plane hip movements relate to fastness and quickness of lateral cutting maneuvers from sliding. Three-dimensional biomechanical data were obtained for 28 female college basketball players while they performed lateral cutting maneuvers using their left leg after 2 lateral sliding steps. The lateral cutting index (LCIndex) expressing fastness and quickness of lateral cutting maneuvers, peak hip abduction and extension velocities immediately before foot contact, hip abduction and extension velocities at foot contact, peak horizontal ground reaction force, frontal plane ground reaction force angle, and sacrum center of mass position were calculated. Simple and stepwise regression analyses were conducted to predict LCIndex. The former showed that greater maximum hip extension velocity (p = 0.03) and lesser hip abduction velocity (p = 0.04) as well as smaller ground reaction force angle (p = 0.001) and lower sacrum center of mass position (p = 0.001) at foot contact led to better LCIndex. The latter showed that sacrum center of mass position at foot contact and hip extension velocity explained 35.3% (p < 0.01) and 7.3% (p = 0.088) of variance in LCIndex, respectively. Our results did not suggest that hip abductor function is important for lateral sliding moves, instead suggesting that faster hip extension motions to kick the ground and lowering the body center of mass are crucial for better lateral deceleration-acceleration motions.

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Strenuous exercise may have the detrimental effects on visual perception. However, it is unclear whether visual resolution is related to the detrimental effects on visual perception. The purpose of this study was to examine whether the effects of strenuous exercise on visual perception are dependent on visual resolution. Given that visual resolution decreases in the periphery of the visual field, we hypothesized that if visual resolution plays a role in the detrimental effects on visual perception, the detrimental effects may be exaggerated toward the periphery of the visual field. Simple visual reaction time was measured at rest and during cycling at 40% and 75% peak oxygen uptakes (VO(2)). Visual stimuli were randomly presented at 2°, 10°, 30°, and 50° to either the right or left of the midpoint between the eyes with equal probability. RT was fractionated into premotor and motor components (i.e. premotor time and motor time) based on electromyographic recording. The premotor time during exercise at 40% peak VO(2) was not different from that at rest. In contrast, the premotor time during exercise at 75% peak VO(2) was significantly longer than that at rest (p=0.018). The increase in the premotor time was observed irrespective of eccentricity, and the detrimental effects were not exaggerated toward the periphery of the visual field. The motor time was not affected by exercise. The current findings suggest that the detrimental effects of strenuous exercise on visual perception are independent of visual resolution.

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This study tested whether cerebral oxygenation affects cognitive function during exercise. We measured reaction times (RT) of 12 participants while they performed a modified version of the Eriksen flanker task, at rest and while cycling. In the exercise condition, participants performed the cognitive task at rest and while cycling at three workloads [40, 60, and 80% of peak oxygen uptake ([Formula: see text])]. In the control condition, the workload was fixed at 20 W. RT was divided into premotor and motor components based on surface electromyographic recordings. The premotor component of RT (premotor time) was used to evaluate the effects of acute exercise on cognitive function. Cerebral oxygenation was monitored during the cognitive task over the right frontal cortex using near-infrared spectroscopy. In the exercise condition, we found that premotor time significantly decreased during exercise at 60% peak [Formula: see text] relative to rest. However, this improvement was not observed during exercise at 80% peak [Formula: see text]. In the control condition, premotor time did not change during exercise. Cerebral oxygenation during exercise at 60% peak [Formula: see text] was not significantly different from that at rest, while cerebral oxygenation substantially decreased during exercise at 80% peak [Formula: see text]. The present results suggest that an improvement in cognitive function occurs during moderate exercise, independent of cerebral oxygenation.

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The purpose of this study was to test the hypothesis that decrease in cerebral oxygenation compromises an individual's ability to respond to peripheral visual stimuli during exercise. We measured the simple reaction time (RT) to peripheral visual stimuli at rest and during and after cycling at three different workloads [40%, 60%, and 80% peak oxygen uptake (VO2)] under either normoxia [inspired fraction of oxygen (FIO2)=0.21] or normobaric hypoxia (FIO2=0.16). Peripheral visual stimuli were presented at 10 degrees to either the right or the left of the midpoint of the eyes. Cerebral oxygenation was monitored during the RT measurement over the right frontal cortex with near-infrared spectroscopy. We used the premotor component of RT (premotor time) to assess effects of exercise on the central process. The premotor time was significantly longer during exercise at 80% peak VO2 (normoxia: 214.2+/-33.0 ms, hypoxia: 221.5+/-30.1 ms) relative to that at rest (normoxia: 201.0+/-27.2 ms, hypoxia: 202.9+/-29.7 ms) (P<0.01). Under normoxia, cerebral oxygenation gradually increased up to 60% peak VO2 and then decreased to the resting level at 80% peak VO2. Under hypoxia, cerebral oxygenation progressively decreased as exercise workload increased. We found a strong correlation between increase in premotor time and decrease in cerebral oxygenation (r2=0.89, P<0.01), suggesting that increase in premotor time during exercise is associated with decrease in cerebral oxygenation. Accordingly, exercise at high altitude may compromise visual perceptual performance.

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We investigated whether the order of gaze shifts affected spatial and temporal aspects of discrete bimanual pointing movements. Ten male participants concurrently executed bimanual pointing movements as quickly and accurately as possible to left and right lateral targets presented with the same and different amplitudes. They were asked to gaze initially at the left target and subsequently at the right target, or vice versa. Each hand showed less variable error and a faster reaction when the initial gaze shifted to the corresponding target than when the subsequent gaze shifted to it. For the same-amplitude targets, constant error (CE) was not influenced by the gaze order conditions. However, for the different-amplitude targets, CE for the short-amplitude target became larger when they initially gazed at the long-amplitude target than when they initially gazed at the short-amplitude target. The larger overshoot of the hand for the short-amplitude target occurred when the participants could not afford to foveate the target. Our results suggest that the order of gaze shifts determines whether asymmetric amplitude assimilation between the two hands occurs or not. Fast, consistent, and accurate bimanual pointing movements might be attributable to updating gaze-centered representations of target positions.

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The purpose of this study was to test if increased oxygen availability affected simple reaction time (RT) to peripheral visual stimuli during exercise. Twelve male participants performed RT tasks at rest, during cycling with three different workloads (100, 150, and 200 W), and after exercise. We fractionated RT into Premotor time and Motor time. Under normoxia, Premotor time significantly increased during exercise at 200 W (mean +/- SD, 224.7 +/- 34.8 ms) relative to that at rest (213.3 +/- 34.1 ms) (P < 0.05). In contrast, we found no difference in Premotor time between at rest (214.0 +/- 27.0 ms) and at 200 W (213.0 +/- 21.6 ms) under hyperoxia. Furthermore, Premotor time significantly decreased at 150 W (201.3 +/- 22.4 ms) relative to that at rest under hyperoxia (P < 0.05). These results suggest that increased oxygen availability during exercise has beneficial effects on perceptual performance.

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To investigate the interference effect in volleyball players and nonathletes (ns=10) when they executed both saccadic and key-press reaction time (RT) tasks concurrently, the two groups responded to the onset of peripheral visual stimuli as quickly as possible in single and dual conditions. In the single condition, subjects responded with either saccadic eye or key-press movement. In the dual condition, they responded concurrently with both saccadic eye and key-press movements. In both groups, the key-press RT was longer in the dual condition than in the single condition. However, the amount of key-press RT delay was remarkably smaller for the volleyball players than for nonathletes. This suggests the motor command to initiate manual movement of volleyball players might be less interfered with by a concurrent oculomotor command to initiate saccadic eye movement when compared to that of nonathletes.

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The purpose of the present study was to determine whether reaction time (RT) for the peripheral visual field increases at exercise intensity above the ventilatory threshold (VT) during incremental exercise and to examine the relationship between aerobic capacity and the extent of increase in the RT. Nine healthy subjects performed a simple manual RT task for the peripheral visual field at rest, during exercise on a cycle ergometer, and immediately after exercise. After warm-up exercise, the subjects cycled at 40 W for 3 min, increasing by 40 W every 3 min until 240 W in a step-wise manner. During incremental exercise, RT measurements were performed 1 min and 30 s after the start of every increase in workload. The RT for the peripheral visual field significantly increased at exercise intensity above VT, as compared with at rest. The increase in the RT, which was calculated by subtracting the RT at rest from the RT at 240 W, negatively correlated with maximal oxygen uptake VO(2max) for each subject (r = -0.73, P < 0.05). It is likely that high aerobic capacity attenuates the increase in the RT for the peripheral visual field during exhaustive exercise.

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The present study examined whether attention can be evenly distributed within the large area of the visual field. The stimulus was presented at one of four locations on the horizontal meridian (0 degrees, 10 degrees, 20 degrees, and 30 degrees to the right). In the Fixed Location condition, the stimulus appeared repeatedly at the same location. In the Random Location condition, the stimulus appeared at one of four locations as determined randomly with equal probability. Reaction times (RTs) in the Random Location condition were significantly longer than those in the Fixed Location condition at the 0 degrees and 30 degrees locations, while there were no significant differences at the 10 degrees and 20 degrees locations. The differences in the RT between conditions were significantly larger at the 0 degrees and 30 degrees locations than those at the 10 degrees and 20 degrees locations. These results suggest that attention was oriented to intermediate locations within the large area of the visual field.

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