Temporal properties of preparation phase for arm-pointing movements in various directions and distances.

In this study, we investigated how the temporal properties of the preparation phase for upper limb movements are affected by the reaching direction and distance. Twelve right-handed participants performed three motor tasks: two types of reaching movements and one finger-lifting movement. The reaching movements were performed from the home position to 15 target locations (five directions and three distances) as quickly and precisely as possible under two conditions: pre-cueing the target to allocate the sufficient time for the motor-planning process before movement initiation, and no-cuing.

Temporal properties of the speed-accuracy trade-off for arm-pointing movements in various directions around the body.

Human body movements are based on the intrinsic trade-off between speed and accuracy. Fitts's law (1954) shows that the time required for movement is represented by a simple logarithmic equation and is applicable to a variety of movements. However, few studies have determined the role of the direction in modulating the performance of upper limb movements and the effects of the interactions between direction and distance and between direction and target size.

Evaluation of soccer team defense based on prediction models of ball recovery and being attacked: A pilot study.

With the development of measurement technology, data on the movements of actual games in various sports can be obtained and used for planning and evaluating the tactics and strategy. Defense in team sports is generally difficult to be evaluated because of the lack of statistical data. Conventional evaluation methods based on predictions of scores are considered unreliable because they predict rare events throughout the game.

Dynamic arm movements attenuate the perceptual distortion of visual vertical induced during prolonged whole-body tilt.

Concurrent body movements have been shown to enhance the accuracy of spatial judgment, but it remains unclear whether they also contribute to perceptual estimates of gravitational space not involving body movements. To address this, we evaluated the effects of static or dynamic arm movements during prolonged whole-body tilt on the subsequent perceptual estimates of visual or postural vertical. In Experiment 1, participants were asked to continuously perform static or dynamic arm movements during prolonged tilt, and we assessed their effects on the prolonged tilt-induced shifts of subjective visual vertical (SVV) at a tilted position (during-tilt session) or near upright (post-tilt session).

Effect of dynamic visual motion on perception of postural vertical through the modulation of prior knowledge of gravity.

To internally estimate gravitational direction and body orientation, the central nervous system considers several sensory inputs from the periphery and prior knowledge of gravity. It is hypothesized that the modulation of visual inputs, supplying indirect information of gravity, affects the prior knowledge established internally by other sensory inputs from vestibular and somatosensory systems, leading to the alteration of perceived body orientation relative to gravity. In order to test the hypothesis, we examined the effect of presenting a visual motion stimulus during a whole-body static tilt on the subsequent evaluation of the perceived postural vertical.

The kinetic mechanisms of vertical pointing movements.

The present study utilized induced acceleration analysis to clarify the contributions of muscular and gravitational torques to the kinematics of vertical pointing movements performed by the upper limb. The study included eight healthy men with a mean age of 25 years. The experiment was divided into three blocks with ten trials in each, comprising five upward and five downward, randomly executed movements.

Whole-Body Roll Tilt Influences Goal-Directed Upper Limb Movements through the Perceptual Tilt of Egocentric Reference Frame.

In our day-to-day life, we can accurately reach for an object in our gravitational environment without any effort. This can be achieved even when the body is tilted relative to gravity. This is accomplished by the central nervous system (CNS) compensation for gravitational forces and torque acting on the upper limbs, based on the magnitude of body tilt.

Motor control of downward object-transport movements with precision grip by object weight.

In the present study, we investigated the kinematics of object-transport movement in a downward direction using a precision grip, to elucidate how the central nervous system (CNS) takes into account object weight when making the movement, even when participants are unable to recognize the weight until they grasp the object. We found that the kinematics during transport movement were significantly changed by the object weight, even when the weight was unrecognized visually, suggesting that the CNS controls object-transport movement in a downward direction according to object weight, regardless of the visual recognizability of the weight.

The role of GABAB receptors in the vestibular oculomotor system in mice.

Systemic administration of a gamma-amino butyric acid type B (GABAB) receptor agonist, baclofen, affects various physiological and psychological processes. To date, the effects on oculomotor system have been well characterized in primates, however those in mice have not been explored. In this study, we investigated the effects of baclofen focusing on vestibular-related eye movements.

Observation of interactive behavior increases corticospinal excitability in humans: A transcranial magnetic stimulation study.

In humans, observation of others' behaviors increases corticospinal excitability (CSE), which is interpreted in the contexts of motor resonance and the "mirror neuron system" (MNS). It has been suggested that observation of another individual's behavior manifests an embodied simulation of his/her mental state through the MNS. Thus, the MNS may involve understanding others' intentions of behaviors, thoughts, and emotions (i.

Direction-dependent differences in temporal kinematics for vertical prehension movements.

In our daily lives, we can appropriately perform movements on the earth, suggesting that the central nervous system takes into account gravitational forces that act on our bodies during the movements. Recently, gravitational forces have been observed to generate the direction-dependent differences in the spatial properties of the kinematics of prehension movements. However, little is known about how gravitational forces affect the temporal properties of the kinematics of these movements.

Difference in perception of angular displacement according to applied waveforms.

Conclusions: This study shows that the differences in the waveforms of angular rotation affect the perception and memory of angular displacement.

Objectives: During daily life, when we turn our head during various activities, our brain calculates how much angular displacement our head has undergone. However, how we obtain an accurate estimation of this angular displacement remains unclarified.

Differences between otolith- and semicircular canal-activated neural circuitry in the vestibular system.

In the last two decades, we have focused on establishing a reliable technique for focal stimulation of vestibular receptors to evaluate neural connectivity. Here, we summarize the vestibular-related neuronal circuits for the vestibulo-ocular reflex, vestibulocollic reflex, and vestibulospinal reflex arcs. The focal stimulating technique also uncovered some hidden neural mechanisms.

Effect of chewing gum on static posturography in patients with balance disorders.

Conclusion: The chewing gum indirectly affects postural control by influencing vestibular function to stabilize posture during upright standing.

Objectives: This study aimed to evaluate the effect of chewing gum on static posturography in patients.

Methods: The subjects were 26 patients with chronic balance disorders.

Effect of masticating chewing gum on postural stability during upright standing.

The purpose of this study was to investigate the effect of masticating chewing gum on postural stability during upright standing. To address this issue, 12 healthy subjects performed quiet standing on a force platform for the posturography study. The subjects were instructed to stand as stable as possible on the force platform in order to record the trajectory of the center-of-pressure (COP).

Effect of anxiety on antero-posterior postural stability in patients with dizziness.

The purpose of this study was to investigate the effect of anxiety on the postural stability of a variety of dizzy patients during upright standing. To address this issue, 54 patients complaining of dizziness were enrolled in this study. The degree of anxiety in patients was evaluated on the basis of a routine vestibular examination together with their dizziness handicap inventory (DHI) scores as well as the hospital anxiety and depression scale (HADS).

Properties and axonal trajectories of posterior semicircular canal nerve-activated vestibulospinal neurons.

We studied the axonal projections of vestibulospinal neurons activated from the posterior semicircular canal. The axonal projection level, axonal pathway, and location of the vestibulospinal neurons originating from the PC were investigated in seven decerebrated cats. Selective electrical stimulation was applied to the PC nerve, and extracellular recordings in the vestibular nuclei were performed.

Frame of reference for visual perception in young infants during change of body position.

The visual and vestibular systems begin functioning early in life. However, it is unclear whether young infants perceive the dynamic world based on the retinal coordinate (egocentric reference frame) or the environmental coordinate (allocentric reference frame) when they encounter incongruence between frames of reference due to changes in body position. In this study, we performed the habituation-dishabituation procedure to assess novelty detection in a visual display, and a change in body position was included between the habituation and dishabituation phases in order to test whether infants dishabituate to the change in stimulus on the retinal or environmental coordinate.

Compensatory and orienting eye movements induced by off-vertical axis rotation (OVAR) in monkeys.

Nystagmus induced by off-vertical axis rotation (OVAR) about a head yaw axis is composed of a yaw bias velocity and modulations in eye position and velocity as the head changes orientation relative to gravity. The bias velocity is dependent on the tilt of the rotational axis relative to gravity and angular head velocity. For axis tilts <15 degrees, bias velocities increased monotonically with increases in the magnitude of the projected gravity vector onto the horizontal plane of the head.

Morphology of physiologically identified otolith-related vestibular neurons in cats.

The morphology of physiologically identified otolith nerve-activated vestibular neurons was investigated using intracellular injections of horseradish peroxidase (HRP). Eleven utricular, 11 saccular and three utricular/saccular nerve-activated vestibular neurons were labeled with HRP. All of these neurons except one were secondary neurons, the exception being a convergent neuron.