Objective: Noisy galvanic vestibular stimulation (GVS) using weak random noise waveforms enhances postural stability by modulating vestibular-related neural networks. This study aimed to investigate the neural interference mechanisms of noisy GVS on lateral vestibulospinal tract (LVST) excitability.
Methods: Twenty-six healthy volunteers were randomly divided into two groups: balance training combined with noisy GVS and sham GVS.
Face recognition is an important aspect of human non-verbal communication. Event-related potentials or magnetic fields, such as the N170/M170 component, are considered essential neural markers of face processing. Compared to upright human faces, inverted human faces and upright but not inverted animal faces cause longer latencies and larger amplitudes of these components.
View Article and Find Full Text PDFBackground: Transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal cortex (DLPFC) is a promising technique for enhancing working memory (WM) performance in healthy and psychiatric populations. However, limited information is available about the effectiveness of transcranial random noise stimulation (tRNS) applied to the left DLPFC on WM. This study investigated the effectiveness of tRNS on WM compared with that of tDCS, which has established functional evidence.
View Article and Find Full Text PDFThe posterior parietal cortex plays an important role in postural stability by adapting to changes in input from the visual, vestibular, and proprioceptive systems. However, little is known regarding whether transcranial electrical stimulation of the posterior parietal cortex affects reactive postural responses. This study aimed to investigate changes in physical control responses to anodal and cathodal transcranial direct current stimulation and transcranial random noise stimulation of the right posterior parietal cortex using a simultaneous inertial measurement unit.
View Article and Find Full Text PDFVestibular nuclei and cerebellar function comprise vestibular neural networks that control vestibular-related responses. However, the vestibular-related responses to simultaneous stimulation of these regions are unclear. This study aimed to examine whether the combination of noisy galvanic vestibular stimulation (nGVS) and cerebellar transcranial direct current stimulation (ctDCS) using a complex transcranial electrical stimulation device alters vestibular-dominant standing stability and vestibulo-ocular reflex (VOR) function.
View Article and Find Full Text PDFBackground: The left dorsolateral prefrontal cortex (DLPFC) is involved in early-phase manual dexterity skill acquisition when cognitive control processes, such as integration and complexity demands, are required. However, the effectiveness of left DLPFC transcranial direct current stimulation (tDCS) on early-phase motor learning and whether its effectiveness depends on the cognitive demand of the target task are unclear. This study aimed to investigate whether tDCS over the left DLPFC improves non-dominant hand dexterity performance and determine if its efficacy depends on the cognitive demand of the target task.
View Article and Find Full Text PDFBackground: Human locomotion induces rhythmic movements of the trunk and head. Vestibular signaling is relayed to multiple regions in the brainstem and cerebellum, and plays an essential role in maintaining head stability. However, how the vestibular-cerebellar network contributes to the rhythmic locomotor pattern in humans is unclear.
View Article and Find Full Text PDFThe effects of passive interpersonal light touch (PILT) on postural stability can be observed through improved postural coordination through haptic feedback from the contact provider to the contact receiver while walking. It is unclear, however, whether PILT affects the contact receiver's detailed physical responses, such as muscle activity, body sway, and joint movements. In this study, surface electromyography and an inertial measurement unit were used simultaneously to explore changes in walking speed and control responses induced by PILT.
View Article and Find Full Text PDFBackground: A wristband-type consumer physical activity tracker (PAT) is commonly used in rehabilitation to assess an individual's physical activity. However, under the free-living setting, the wristband-type PAT tends to overestimate step counts when compared with the research-standard criterion. Also, daily rhythm characteristics, such as sleep time, are difficult to monitor accurately based solely on self-reporting.
View Article and Find Full Text PDFObjective: Noisy galvanic vestibular stimulation (nGVS) is an effective method for stabilizing posture; however, little is known regarding the detailed muscle activity and joint movement in the standing posture. This study aimed to clarify the changes in the lower limb muscle activity and joint angular velocity by nGVS intervention using the simultaneous assessment method of inertial measurement units and surface electromyography (EMG).
Methods: Seventeen healthy participants were assessed for their physical responses under four conditions (standing on a firm surface with eyes-open/eyes-closed, and a foam surface with eyes-open/eyes-closed) without stimulation (baseline) and with stimulation (sham or nGVS).
Objectives: In post-stroke patients, shifts in the center of gravity may affect joint movement patterns of the paraplegic lower limb during walking. The impact of changes in ankle dorsiflexion angle and trailing limb angle due to slight weight-shifting is unknown. This study aimed to investigate the effect of the abovementioned parameters on gait characteristics measured by trunk acceleration.
View Article and Find Full Text PDFIntermittent theta-burst stimulation (iTBS) using transcranial magnetic stimulation (TMS) is known to produce excitatory after-effects over the primary motor cortex (M1). Recently, transcranial alternating current stimulation (tACS) at 10 Hz (α) and 20 Hz (β) have been shown to modulate M1 excitability in a phase-dependent manner. Therefore, we hypothesized that tACS would modulate the after-effects of iTBS depending on the stimulation frequency and phase.
View Article and Find Full Text PDFTranscranial alternating current stimulation (tACS) at 20 Hz (β) has been shown to modulate motor evoked potentials (MEPs) when paired with transcranial magnetic stimulation (TMS) in a phase-dependent manner. Repetitive paired-pulse TMS (rPPS) with I-wave periodicity (1.5 ms) induced short-lived facilitation of MEPs.
View Article and Find Full Text PDFIntroduction: Subliminal affective priming effects (SAPEs) refer to the phenomenon by which the presentation of an affective prime stimulus influences the subsequent affective evaluation of a target stimulus. Previous studies have reported that unconsciously processed stimuli affect behavioral performance more than consciously processed stimuli. However, the impact of SAPEs on the face-specific N170 component is unclear.
View Article and Find Full Text PDFObjectives: This study aimed to investigate whether the combination of transcranial direct current stimulation (tDCS) and gait training with FES affected walking speed and trunk accelerometry-based gait characteristics in patients with subacute stroke, compared with FES or tDCS gait training only.
Materials And Methods: Stroke patients (n = 34; female 15; mean age, 72.5 ± 11.
Transcranial static magnetic stimulation (tSMS) has been known to reduce human cortical excitability. Here, we investigated whether tSMS would modulate visuo-spatial cognition in healthy humans. Subjects performed a visuo-spatial task requiring judgements about the symmetry of pre-bisected lines.
View Article and Find Full Text PDFBackground: Transcranial alternating current stimulation (tACS) can entrain and enhance cortical oscillatory activity in a frequency-dependent manner. In our previous study (Nakazono et al., 2016), 20 Hz (β) tACS significantly increased excitability of primary motor cortex compared with 10 Hz (α) tACS.
View Article and Find Full Text PDFBackground: The motor evoked potentials (MEPs) elicited by single-pulse transcranial magnetic stimulation (TMS) vary considerably at rest, but the mechanism underlying this amplitude variation is largely unknown. We hypothesized that prestimulus EEG oscillations modulate the subsequent MEPs in a state-dependent manner.
Objective: We studied the relationship between prestimulus alpha/beta oscillations and MEPs during eyes open (EO)/closed (EC) conditions, and then modulated TMS intensity in the EO condition.
Key Points: Ischaemic nerve block (INB) of the forearm rapidly reduces somatosensory input to a part of the body, which leads to the functional reorganization of the temporarily deafferented primary motor cortex (M1). We applied a novel modified INB (mINB) to the forearm, maintaining mean blood pressure, to assess cortical plasticity in the primary somatosensory cortex (S1) and the M1 regions associated with small hand muscles. S1 excitability was measured by median nerve somatosensory-evoked potentials (SEPs), while M1 excitability was evaluated by motor-evoked potentials (MEPS), using transcranial magnetic stimulation.
View Article and Find Full Text PDFTranscranial alternating current stimulation (tACS) can entrain ongoing brain oscillations and modulate the motor system in a frequency-dependent manner. Recent animal studies have demonstrated that the phase of a sinusoidal current also has an important role in modulation of neuronal activity. However, the phase effects of tACS on the human motor system are largely unknown.
View Article and Find Full Text PDFBackground: The human visual system processes different aspects of visual information such as luminance and contrast via multiple channels. We previously used repetitive paired-pulse stimulation (rPPS) over the visual cortex to elicit a disinhibitory effect on the visual recovery function of paired pattern-reversal (PR) visual evoked potentials (VEPs).
Objective: We tested the hypothesis that different visual channels exhibit diverse response patterns after rPPS over the visual cortex.
Cricoid cartilage fractures usually occur concurrently with disorders of laryngeal function. In, particular, displaced cricoid lamina fractures can affect arytenoid movement. However, functional, recovery may require proper repositioning of the cricoid lamina, which is associated with a high rate of, complications.
View Article and Find Full Text PDFMethoxy polyethylene glycol-epoetin beta, a continuous erythropoietin receptor activator (CERA), is reported to be effective in managing renal anemia but there is little data about CERA in Japan. This study aimed to ascertain the effects of CERA in Japanese hemodialysis patients and the appropriate starting dose of CERA when switching from other erythropoiesis-stimulating agents. We switched 61 stable hemodialysis patients to 4-weekly intravenous CERA, from either epoetin beta (rHuEPO) or darbepoetin alpha (DA).
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