Older adults exhibit more bilateral motor cortical activity during unimanual task performance than young adults. Interestingly, a similar pattern is seen in young adults with reduced hand dominance. However, older adults report stronger hand dominance than young adults, making it unclear how handedness is manifested in the aging motor cortex. Here, we investigated age differences in the relatio...

Using transcranial magnetic stimulation (TMS), we examined whether sensory input from a finger affects activity of the ipsilateral primary motor cortex (M1) when human subjects hold a virtual object bimanually and whether this ipsilateral activation varies under different contexts. Subjects used both index fingers to hold two plates, which were subjected to unpredictable pulling loads from torq...

Short-latency afferent inhibition (SAI) occurs when a single transcranial magnetic stimulation (TMS) pulse delivered over the primary motor cortex is preceded by peripheral electrical nerve stimulation at a short inter-stimulus interval (∼ 20-28 ms). SAI has been extensively examined at rest, but few studies have examined how this circuit functions in the context of performing a motor task and ...

To explore the effect of mirror box therapy based on the mirror neuron (MN) system of the primary motor cortex (M1), we examined if direct (without a mirror) and indirect (with a mirror) observation of self-movement in healthy subjects induced changes in motor evoked potential (MEP) evoked by transcranial magnetic stimulation. MEPs were elicited from the first dorsal interosseous and the flexor...

At about the 20-30 day of embryonic life "Somites" start to appear. In the middle of the fourth week the dorsal portion of each Somite differentiates into an epithelially­arranged mass of cells called der­momyotome (from which the skin and mus­cles originate).  The lateral part of the sermomyotome then proliferates to form dermatome (from ·which originates the derm and Hypoderm).  The medial ...

It is known that at any given force level, the lower-threshold motor units generally fire at greater rates than the higher-threshold units during isometric tasks of extremity muscles. In addition to this hierarchical arrangement, firing rates of motor units fluctuate in unison with nearly no time delay; an observation that has led to the concept of common drive, a basic motoneuronal rule. Altho...

Although facilitation of the cortico-spinal system during action observation is widely accepted, it remains controversial whether this facilitation reflects a replica of the observed movements or the goal of the observed motor acts. In the present transcranial magnetic stimulation study, we recorded motor evoked potentials from two hand muscles (first dorsal interosseous and abductor digiti min...

Transcranial magnetic stimulation (TMS) research has shown that corticospinal excitability is facilitated during the observation of human movement. However, the relationship between corticospinal excitability and participants' visual attention during action observation is rarely considered. Nineteen participants took part in four conditions: (i) a static hand condition, involving observation of...

Corticomuscular coherence (CMC) is an oscillatory synchronization of 15-35 Hz (β-band) between electroencephalogram (EEG) of the sensorimotor cortex and electromyogram of contracting muscles. Although we reported that the magnitude of CMC varies among individuals, the physiological mechanisms underlying this variation are still unclear. Here, we aimed to investigate the associations between CMC...

PURPOSE The aim of this pilot study was to evaluate the potential of a new noninvasive optical measurement of muscle oxygenation (MOx) to identify shock severity in patients with suspected sepsis. METHODS We enrolled 51 adult patients in the emergency department (ED) who presented with possible sepsis using traditional Systematic Inflammatory Response Syndrome criteria or who triggered a "Cod...