Validation of the ULCEAT methodology by applying it in retrospect to the Roboticbed.

Background: In answer to the increasing demand for care by the Japanese oldest portion of the population, an extensive programme of life support robots is under development, advocated by the Japanese government. Roboticbed (RB) is developed to facilitate patients in their daily life in making independent transfers from and to the bed. The bed is intended both for elderly and persons with a disability.

Rapid P300 brain-computer interface communication with a head-mounted display.

Visual ERP (P300) based brain-computer interfaces (BCIs) allow for fast and reliable spelling and are intended as a muscle-independent communication channel for people with severe paralysis. However, they require the presentation of visual stimuli in the field of view of the user. A head-mounted display could allow convenient presentation of visual stimuli in situations, where mounting a conventional monitor might be difficult or not feasible (e.

Effects of training and motivation on auditory P300 brain-computer interface performance.

Objectives: Brain-computer interface (BCI) technology aims at helping end-users with severe motor paralysis to communicate with their environment without using the natural output pathways of the brain. For end-users in complete paralysis, loss of gaze control may necessitate non-visual BCI systems. The present study investigated the effect of training on performance with an auditory P300 multi-class speller paradigm.

Sound can suppress visual perception.

In a single modality, the percept of an input (e.g., voices of neighbors) is often suppressed by another (e.

Effects of aging and idiopathic Parkinson's disease on tactile temporal order judgment.

It is generally accepted that the basal ganglia play an important role in interval timing that requires the measurement of temporal durations. By contrast, it remains controversial whether the basal ganglia play an essential role in temporal order judgment (TOJ) of successive stimuli, a behavior that does not necessarily require the measurement of durations in time. To address this issue, we compared the effects of idiopathic Parkinson's disease (PD) on the TOJ of two successive taps delivered to each hand, with the arms uncrossed in one condition and crossed in another.

Absence of predispositional attentional sensitivity to angry faces in children with autism spectrum disorders.

A rapid allocation of attention towards threatening stimuli in the environment is crucial for survival. Angry facial expressions act as threatening stimuli, and capture humans' attention more rapidly than emotionally positive facial expressions - a phenomenon known as the Anger Superiority Effect (ASE). Despite atypical emotional processing, adults with Autism Spectrum Disorders (ASD) have been reported to show ASE similar to typically developed (TD) individuals.

Neuropsychological profiles of patients with 2q37.3 deletion associated with developmental dyspraxia.

Patients with 2q37 deletions manifest brachydactyly mental retardation syndrome (BDMR). Recent advances in human molecular research have revealed that alterations in the histone deacetylase 4 gene (HDAC4) are responsible for the clinical manifestations of BDMR. Here, we report two male patients with 2q37.

Mini-max feedback control as a computational theory of sensorimotor control in the presence of structural uncertainty.

We propose a mini-max feedback control (MMFC) model as a robust approach to human motor control under conditions of uncertain dynamics, such as structural uncertainty. The MMFC model is an expansion of the optimal feedback control (OFC) model. According to this scheme, motor commands are generated to minimize the maximal cost, based on an assumption of worst-case uncertainty, characterized by familiarity with novel dynamics.

Spatio-temporal processing of tactile stimuli in autistic children.

Altered multisensory integration has been reported in autism; however, little is known concerning how the autistic brain processes spatio-temporal information concerning tactile stimuli. We report a study in which a crossed-hands illusion was investigated in autistic children. Neurotypical individuals often experience a subjective reversal of temporal order judgments when their hands are stimulated while crossed, and the illusion is known to be acquired in early childhood.

Principal component analysis reveals differential attentional modulation of the vocal response to pitch perturbation.

The auditory-vocal system modifies voice fundamental frequency (F0) with auditory feedback. The responses to F0 changes in auditory feedback are known to depend on the task. The hypothesis explored in this study is that the task dependency is the result of multiple components of the F0 responses differently modulated with different tasks.

Coherent Activity in Bilateral Parieto-Occipital Cortices during P300-BCI Operation.

The visual P300 brain-computer interface (BCI), a popular system for electroencephalography (EEG)-based BCI, uses the P300 event-related potential to select an icon arranged in a flicker matrix. In earlier studies, we used green/blue (GB) luminance and chromatic changes in the P300-BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray (WG) luminance flicker matrix. To highlight areas involved in improved P300-BCI performance, we used simultaneous EEG-fMRI recordings and showed enhanced activities in bilateral and right lateralized parieto-occipital areas.

Attempt toward a development of aquatic exercise device for gait disorders.

Purpose: To develop an aquatic exercise device to facilitate locomotive motor output and achieve repetitive physiological gait patterns to improve movement dysfunctions.

Methods: A custom designed leg movement apparatus (LMA) consisted of closed 4-linkage mechanisms and one-length changeable link using a spring. Three-dimensional motions and electromyographic (EMG) activities were recorded in eight healthy subjects to evaluate the reproducibility of the physiological gait patterns using the LMA with or without a spring apparatus in water.

A region-based two-step P300-based brain-computer interface for patients with amyotrophic lateral sclerosis.

Objective: The P300-based brain-computer interface (BCI) is designed to help patients with motor disabilities to control their environment, and it has been used successfully in patients with amyotrophic lateral sclerosis (ALS). However, some ALS patients were unable to use the visual P300-BCI with the conventional row/column presentation. In this study, we evaluated the effect of a newly developed region-based two-step P300 speller, which has a larger flashing area than the conventional visual array.

Neural correlate of human reciprocity in social interactions.

Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans.

Implementation of a beam forming technique in real-time magnetoencephalography.

Real-time magnetoencephalography (rtMEG) is an emerging neurofeedback technology that could potentially benefit multiple areas of basic and clinical neuroscience. In the present study, we implemented voxel-based real-time coherence measurements in a rtMEG system in which we employed a beamformer to localize signal sources in the anatomical space prior to computing imaginary coherence. Our rtMEG experiment showed that a healthy subject could increase coherence between the parietal cortex and visual cortex when attending to a flickering visual stimulus.

A BMI-based occupational therapy assist suit: asynchronous control by SSVEP.

A brain-machine interface (BMI) is an interface technology that uses neurophysiological signals from the brain to control external machines. Recent invasive BMI technologies have succeeded in the asynchronous control of robot arms for a useful series of actions, such as reaching and grasping. In this study, we developed non-invasive BMI technologies aiming to make such useful movements using the subject's own hands by preparing a BMI-based occupational therapy assist suit (BOTAS).

Effect of hopping frequency on bilateral differences in leg stiffness.

Understanding the degree of leg stiffness during human movement would provide important information that may be used for injury prevention. In the current study, we investigated bilateral differences in leg stiffness during one-legged hopping. Ten male participants performed one-legged hopping in place, matching metronome beats at 1.

A non-adhesive solid-gel electrode for a non-invasive brain-machine interface.

A non-invasive brain-machine interface (BMI) or brain-computer interface is a technology for helping individuals with disabilities and utilizes neurophysiological signals from the brain to control external machines or computers without requiring surgery. However, when applying electroencephalography (EEG) methodology, users must place EEG electrodes on the scalp each time, and the development of easy-to-use electrodes for clinical use is required. In this study, we developed a conductive non-adhesive solid-gel electrode for practical non-invasive BMIs.

Effect of the Green/Blue Flicker Matrix for P300-Based Brain-Computer Interface: An EEG-fMRI Study.

The visual P300-brain-computer interface, a popular system for EEG-based BCI, utilizes the P300 event-related potential to select an icon arranged in a flicker matrix. In the conventional P300-BCI speller paradigm, white/gray luminance intensification of each row/column in the matrix is used. In an earlier study, we applied green/blue luminance and chromatic change in the P300-BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray luminance flicker matrix.

Spatio-temporal updating in the left posterior parietal cortex.

Adopting an unusual posture can sometimes give rise to paradoxical experiences. For example, the subjective ordering of successive unseen tactile stimuli delivered to the two arms can be affected when people cross them. A growing body of evidence now highlights the role played by the parietal cortex in spatio-temporal information processing when sensory stimuli are delivered to the body or when actions are executed; however, little is known about the neural basis of such paradoxical feelings resulting from such unusual limb positions.

Limb oxygenation during the cold pressor test in spinal cord-injured humans.

Objective: To investigate changes in tissue oxygenation in the arm and leg during the cold pressor test in humans with spinal cord injury (SCI).

Methods: Subjects with SCI at cervical 6 (n=7) and subjects with SCI at thoracic 5 or thoracic 6 (n=5) experienced 3-min cold water immersion of the foot and subsequent 10-min recovery. Changes in tissue oxygenation and blood pressure were determined.

Towards intelligent environments: an augmented reality-brain-machine interface operated with a see-through head-mount display.

The brain-machine interface (BMI) or brain-computer interface is a new interface technology that uses neurophysiological signals from the brain to control external machines or computers. This technology is expected to support daily activities, especially for persons with disabilities. To expand the range of activities enabled by this type of interface, here, we added augmented reality (AR) to a P300-based BMI.

Operation of a P300-based brain-computer interface by individuals with cervical spinal cord injury.

Objective: This study evaluates the efficacy of a P300-based brain-computer interface (BCI) with green/blue flicker matrices for individuals with cervical spinal cord injury (SCI).

Methods: Ten individuals with cervical SCI (age 26-53, all male) and 10 age- and sex-matched able-bodied controls (age 27-52, all male) with no prior BCI experience were asked to input hiragana (Japanese alphabet) characters using the P300 BCI with two distinct types of visual stimuli, white/gray and green/blue, in an 8×10 flicker matrix. Both online and offline performance were evaluated.

Effect of spinal cord injury and its lesion level on stretch reflex modulation by cold stimulation in humans.

Objective: To determine how short-latency stretch reflex amplitude in the soleus muscle is modulated by cold stimulation in able-bodied individuals and individuals with complete spinal cord injury.

Methods: An initial 100-s baseline period was followed by 50-s cold stimulation periods. Stretch reflex of the right soleus muscle was elicited for 10-s intervals, while cold stimulation was applied to the left thigh.