Background; During neurosurgical treatment, it is extremely important to localize of cerebral function to preserve cerebral function and maintain the quality of life of the patients. Recently, hemispheric dominance for language has been assessed using the Wada test in which amobarbital is injected into the carotid artery. However, this is an invasive technique with considerable risk of complications. Herein, we attempted optical topography (OT) along with the findings of the Wada test.
Methods; Eleven patients who underwent craniotomy in this hospital were tested with optical topography during a word generation task. These patients included 3 patients with cerebral aneurysms, 6 with brain tumor, 1 with epilepsy, 1 with cerebral arteriovenous malformation, who were from 13 year to 81 years of age, and comprised of 7 men and 4 women.
Word generation task: Each subject was given 15 seconds to write down as many words as possible, beginning with a randomly presented letter on a computer monitor. In between presentation of letters, subjects were instructed to focus on copying a picture for 30 seconds during which the NIRS baseline was established.
NIRS measurements: We measured the relative changes in oxygenated (Oxy-Hb) deoxygenated hemoglobin (deoxy-Hb) and total hemoglobin, which were calculated by combining the two parameters following collection of NIRS data (ETG-7100; Hitachi Medical Corporation, Tokyo, Japan) during performance of the Word generation task. We subsequently used a region of interest (ROI) and laterality index (LI). Six ROIs were set to determine the useful ROI, and the agreement rate with the Wada test was calculated. The LI, for Oxy-Hb was calculated from L and R, the sum of the concentrations for the activated ROIs over the left and right inferior frontal regions bilaterally, according to the following formula: LI= (L−R)/(L+R). The LI ranged from −1 to 1, where a positive value (0.26 to 1) indicated left language lateralization and a negative value (−1 to −0.26) indicated right language lateralization. A value between −0.25 and 0.25 inclusively was considered to reflect bilateral language dominance.
Results; The results indicated a high agreement ratio in ROI 3, 5, and 6, of which 5 and 6 were included in ROI 3. We subsequently determined the language dominant hemisphere from the foregoing ROI and LI. The results based upon the optical topography were eight left-sided predominance, right predominance in two, and one case of bilateral predominance. Meanwhile, the results of Wada test were eight left-sided predominance, one case each of right and bilateral predominance, and inability to determine in one. The agreement between the techniques was 90% (9/10 case). One evaluation that was impossible by determination using Wada test was possible.
Conclusions; Therefore, this study demonstrates that OT is a feasible clinical application for the identification of the language dominant hemisphere.

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Objective: Sensitivity to scale and non-scale notes was examined in absolute pitch (AP) and non-absolute pitch (NAP) possessors using a mismatch negativity (MMN) paradigm.
Methods: Twenty-six healthy subjects took part in the experiment (22 females, mean age: 21.7±1.6 years old). All participants took an AP test. Twelve participants possessed AP and could identify non-scale notes by naming neighboring scale notes. Fourteen participants were NAP possessors and failed to distinguish between scale and non-scale notes. Two tone pairs were constructed. In the “scale note” condition, standard stimuli were set to the scale note A4 (442 Hz), and deviant stimuli were set to the scale note B4 (496 Hz). The “non-scale note” condition included standard stimuli set to a non-scale note halfway between A4 and B4 (452 Hz) and deviant stimuli set to a non-scale note halfway between B4 and C5 (509 Hz).
Results: AP possessors started musical training earlier (3.4±1.0 mean years of age) than NAP possessors (9.2±8.1 mean years of age). In the scale note condition, MMN amplitude for the AP group was significantly smaller than that for the NAP group. The non-scale note condition did not differ significantly between groups.
Conclusion: Our results suggest that early musical training is needed to possess AP. Furthermore, possessors of AP processed scale notes pre-attentively than non-scale notes.

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[Objective] To report our experience on correlation between surgical outcomes for proximal-type cervical spondylotic amyotrophy (CSA) resulting from unilateral ventral nerve root (VNR) involvement and compound muscle action potentials (CMAPs) of the deltoid and the biceps brachii muscles recorded preoperatively.
[Methods] We retrospectively studied 10 proximal-type CSA patients who underwent surgical treatment of the cervical spine and preoperative CMAP recording from the deltoid and biceps after Erb-point stimulation. The central motor conduction time calculated based on the motor evoked potentials from the abductor digiti minimi after transcranial magnetic stimulation and the F waves excluded the corticospinal tract involvement. The deltoid and biceps CMAPs on the normal side also excluded a possibility of the anterior horn involvement. Postoperative improvement in muscle strength of more than 2 MMT grades or complete recovery was classified as excellent, 1 MMT grade of recovery as good, and no improvement as fair.
[Results] The improvement was graded as excellent in 7 cases, good in 0, and fair in 3. Of the 7 patients graded as excellent, 5 showed the average of CMAP amplitudes for the deltoid and biceps of 30 to 50% on the affected side compared to the normal side, and the remaining 2 patients 10 to 30% on the affected side compared to the normal side. All three patients graded as fair showed the value of 10 to 30%.
[Discussion] The average of deltoid and biceps CMAP amplitudes of less than 30% on the affected side, as compared with the normal side, indicated severe involvement of VNR. Although decompression surgeries for proximal-type CSA, if caused by unilateral VNR involvement, tend to be effective, we must recognize that this is not the case with the severe involvement of VNR as predicted by the deltoid and biceps CMAP of low amplitude.
[Conclusions] In proximal-type CSA with unilateral VNR involvement, the average of side-to-side amplitude ratios of the deltoid and biceps CMAPs recorded preoperatively correlated with postoperative functional recovery. Surgical intervention to the cervical spine in this disorder produces excellent results in patients with the amplitude ratio of 30 to 50%, but this is not always the case in patients with the ratio of less than 30%.

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The objective of this research was to evaluate the autonomic nervous function in photoplethysmography (PS) under emotional stimuli using a cellular phone. Twenty-four healthy subjects were examined. PS was measured under audio-visual stimuli in 3 sessions and sentence stimuli in 2 sessions on a cellular phone. A session consisted of three time repeats of a task for 40 seconds and recall for 180 seconds. Pulse waves from PS were analyzed to estimate the pulse wave amplitude to compare among sessions. The results showed that in the audio-visual stimuli, the pulse wave amplitudes of pleasant and unpleasant stimuli in task and recall were significantly lower than the values of the relax stimuli. The amplitudes of the relax and unpleasant stimuli in recall were significantly higher than the values in task. In the sentence stimuli, the pulse wave amplitudes of the pleasant sentence and unpleasant sentence stimuli in recall were significantly lower than the values in task. These events suggest that the autonomic nervous reaction under the emotional sentence stimuli using a cellular phone would be different from those under the audio-visual stimuli.

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This study investigated the effects of different forms of exercise on night sleep. Seven undergraduate and graduate students (mean±SD: 22.6±1.0 years of age) who did not habitually exercise participated in this study. Sleep stages were discerned using polysomnography during night sleep, and slow wave sleep (SWS) and other sleep factors were analyzed. This experiment consisted of a control session without exercise, and exercise sessions performed a maximum of two hours before bed. The exercise sessions included one hour on a cycle ergometer at an intensity of 50% of heart rate reserve or resistance movements performed at an intensity of 60% with one repetition. As a result, the sleep latencies in both exercise sessions were shorter than that in the control condition. In addition, moderate endurance or resistance exercises increased the percentage of SWS during night sleep when compared to the control condition. These findings suggest that moderate aerobic or resistance exercises are recommended for sedentary people in order to improve the quality of sleep.

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Visual evoked potentials (VEPs) are useful for investigating the physiology and pathophysiology of the human visual system, including visual pathways and the visual cortex. The most commonly used method is pattern reversal (PR) stimulation using either a checkerboard pattern or a grating pattern. Identification of generator sources of VEPs may improve their clinical utility. Since magnetoencephalography has several advantages over electric fields in localizing cortical potentials, there have been a number of studies regarding neural generators of visual evoked magnetic fields (VEFs). In the present study, we have reviewed VEF studies to search for the possible standardization of stimulus parameters for clinical application of VEFs. Only nine papers were met our criteria. Most VEF studies have been focusing on the source localization during the visual tasks to relate the visual function with known physiology and anatomy. In such tasks, neural generators of PR-VEPs have been elucidated. However, stimulus parameters such as check size and size of visual field were varied among the studies. Therefore, one must be cautious when interpreting the results of previous VEF studies. We have commented on the possible problems of the previous studies in terms of the visual physiology.

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