We examined here, changes in event-related potentials (ERPs) in eighteen children from 7 to 12 years and twelve adults. In addition to ERPs, we examined changes of EMG-RT. Subjects performed an auditory target discrimination task, in which 1000 Hz tones (target) and 2000 Hz tones (standard) were randomly presented with probabilities of 0.2 and 0.8.
We found P300 as most consistent component of ERPs since childhood. P300 latency and EMG-RT in children was significantly prolonged than in adults (p<0.01) . P300 amplitude in children was significantly larger than in adults (p<0.05) . We concluded that both stimulus evaluation time and response selection time in children are more prolonged than that in adults, although ERPs is confirmed in children.

Electrophysiologic effects of physical exercise were investigated by comparing a training group and non-training group. ERPs were recorded by oddball paradigm using auditory stimuli as well as count and reaction tasks. EMG-RT was recorded during the reaction task. No reliable exercise effects on N100 amplitudes or latencies were observed. Concerning P300 amplitudes, no significant difference between the training group and non-training group was seen although P300 latencies of the training group were significantly shorter than those of the non-training group in the count task. Moreover, EMG-RT of the training group was significantly shorter than that of the non-training group.
These findings suggest that the long-term physical exercise improved the efficiency of informa-tion processing and superior cognitive function in the brain.

The mechanism of the latent reaction time in task completion in elderly men was investigated by comparing the reaction time (RT), EMG-RT and motor time (MT) in young and elderly men. The motor performance was recorded as task completion through as a WS-RS, simple reaction or a choice reaction for each movement using a handgrip and switch.
In this study, we found that the RT and EMG-RT of elderly men in all movements of WS-RS and choice reaction tasks were significantly longer than those of young men, especially in the choice reaction tasks were striking. Moreover, the MT of elderly men in all tasks was significantly longer than those of young men.
These findings suggest that the latent RT and EMG-RT in a choice reaction task may be due to relayed information processing through as the discrimination and cognition functions in the brain, and that it may be also influenced by the mechanism of the latent reaction time of task completion in elderly men.

We studied whether exercise fatigue affects somatosensorv input using somatosensory evoked potential (SEP) . Sixteen subjects performed intermittent grip strength exercises with muscle fatigue while ignoring electrical stimulation given to an elbow. We induced SEP in the exercise task (during contraction) in every stage (first stage, middle stage and final stage) . In addition, we induced SEP in the exercise task during relaxation in the first stage and final stage. As a result, the early component amplitude of SEP decreased with the progress of exercise (manifestation of muscle fatigue) during contraction and relaxation. Our findings suggested that somatosensory input decreased with the manifestation of muscle fatigue. Somatosensory input is necessary for control of voluntary movement. Therefore, we speculate that these factors play a role in decreased performance of athletes competing in long-duration events.

 Our hospital comprises nine departments of internal medicine that specialize in different organs, and the Department of General Internal Medicine is one of these departments. The inpatient department has 30 beds for providing medical care, and education is provided for junior and senior residents. We examined the diagnoses in 593 cases (289 men, 304 women ; mean age, 64.2±21.2 years old) who were hospitalized in the Department of General Internal Medicine at this hospital between April 2007 and March 2008. The major diseases included pneumonia, 111 cases ; urinary tract infections, 44 cases ; infectious enteritis, 34 cases ; bronchial asthma, 24 cases ; fever of unknown origin, 12 cases ; heart failure, 11 cases ; viral infections 9 cases, diverticulitis, 8 cases ; malignant lymphoma, 7 cases ; infectious mononucleosis, 7 cases ; polymyalgia rheumatica, 6 cases ; and others. In order to provide diagnoses and treatments for cases in which no diagnosis could not be obtained on the first outpatient visit, for example, it is necessary to have a ward for general internal medicine as a location for providing medical care that is not limited to any specialized field.