Search

This study demonstrates the feasibility of a mid-air means of haptic stimulation at a long distance using the plasma effect induced by laser. We hypothesize that the stress wave generated by laser-induced plasma in the air can propagate through the air to reach the nearby human skin and evoke tactile sensation. To validate this hypothesis, we investigated somatosensory responses in the human brain to laser plasma stimuli by analyzing electroencephalography (EEG) in 14 participants. Three types of stimuli were provided to the index finger: a plasma stimulus induced from the laser, a mechanical stimulus transferred through Styrofoam stick, and a sham stimulus providing only the sound of the plasma and mechanical stimuli at the same time. The event-related desynchronization/synchronization (ERD/S) of sensorimotor rhythms (SMRs) in EEG was analyzed. Every participant verbally reported that they could feel a soft tap on the finger in response to the laser stimulus, but not to the sham stimulus. The spectrogram of EEG evoked by laser stimulation was similar to that evoked by mechanical stimulation; alpha ERD and beta ERS were present over the sensorimotor area in response to laser as well as mechanical stimuli. A decoding analysis revealed that classification error increased when discriminating ERD/S patterns between laser and mechanical stimuli, compared to the case of discriminating between laser and sham, or mechanical and sham stimuli. Our neurophysiological results confirm that tactile sensation can be evoked by the plasma effect induced by laser in the air, which may provide a mid-air haptic stimulation method.

This study aimed to compare the cognitive performance and event-related potential (ERP) patterns between females who have given birth (parous) and those who have not (nulliparous). A total of 50 female participants, including 27 who were parous (33.2 ± 3.2 years) and 23 who were nulliparous (30.8 ± 2.3 years), were recruited. Only parous females who were ≤36 months postpartum (17.7 ± 8.1 months) were included. To compare the cognitive performance between the two groups, we presented the 3-back task (a working memory task) and compared the accuracy rate (%) and reaction time (ms) between the groups. Electroencephalogram (EEG) signals were simultaneously recorded and the ERP patterns at Fz, Cz, and Pz, which are highly associated with the 3-back task, were analyzed. From the ERP patterns, we extracted N100, P300, P600, P300 peak-to-peak (P300p_p), and P600 peak-to-peak (P600p_p). There were no significant between-group differences in terms of accuracy rate, reaction time, or ERP components (N100, P300, P600, P300p_p, or P600p_p) at the three sites (Fz, Cz, and Pz). Since this study, using meaningful objective data, did not show that parity was significantly correlated with cognitive performance ability and ERP patterns, childbirth does not appear to influence cognitive decline.

In this study, we attempted to observe changes in cognitive characteristics according to 3 intensity changes (Level 1: 0.25 gravity, Level 2: 0.38 gravity, Level 3: 1.3 gravity) at 8 vibration frequencies (10, 50, 100, 150, 200, 225, 250, 300 Hz). The subjects were twelve male (22.1 ± 0.6 years old) and twelve female (21.5 ± 0.8 years old) healthy, right-handed adults with normal cognitive abilities. An experimental trial consisted of a stimulation phase (0.1 sec) in which a vibration stimulus was presented and a rest phase (6 sec) in which no vibration stimulus was presented. A selected stimulus was presented on the first knuckle of the right index finger 5 times (trials). Cognitive characteristics scores according to changes in intensity at each frequency were sampled using a subjective assessment sheet consisting of eighteen items (“ticklish,” “shivery,” “push,” “convex,” “thick,” “numb,” “slow,” “fast,” “shallow,” “strike,” “weak,” “strong,” “dense,” “blunt,” “heavy,” “light,” “stab”, “no stimulus”). To identify the cognitive characteristics according to intensity changes by frequency, the 3 intensities were designated as variables, and a curve estimation regression analysis was performed. At 10 Hz, cognitive characteristics of ’blunt’ increased with the intensity, and ’weak’ decreased. In 100 and 225 Hz, increase or decrease in intensity led to opposite cognitive characteristics (‘weak-strong’ in 100 and 225 Hz, ‘light-heavy’ in 225 Hz). In 100 and 225 Hz, as the intensity increased, expressions on the sense of surface such as ’blunt’ were superior, and the shape of an object (thick) and dynamics (push) differed with the change in intensity. In addition, in 225 Hz, decrease in intensity led to increase in cognitive characteristics such as ’light’ and 'shallow. ’Fast’ was unique in that it only appeared as the intensity increased at 300 Hz.

BACKGROUND: Variations or malformation of the internal carotid artery (ICA) and basilar artery (BA) can be risk factors during simple surgery. So medically the focus has been on information about the positional relationship between the blood vessels based on the distance and angle between the ICA and BA. OBJECTIVE: This study measured the distance and angle between the ICA and BA in 188 healthy Korean male and female subjects in their 20s and 40s and analyzed the differences in terms of age and gender. METHODS: Magnetic resonance images were obtained; the distance between the right ICA and BA was defined as R1 [cm], the distance between the left ICA and BA was defined as L2 [cm], and the distance between the right ICA and left ICA was defined as M3 [cm]. The angles between the right and left ICA and BA were defined as AR1 [degree] and AR2 [degree], respectively. RESULTS: With increasing age, R1 and M3 became shorter in both men and women, and L2 became shorter only in women. CONCLUSION: The results of this study provide data on the average distance and angle between the ICA and BA of healthy Korean men and women in their 20s and 40s, which may later be used to support the diagnosis of relevant brain diseases and simple routine surgical procedures.

본 연구에서는 끄라차이담을 여러 유용 미생물(BS: Bacillus subtilis, LP: Lactobacillus plantarum, LC: Lactobacillus casei, CU: Candida utilis, Y1: Saccharomyces cerevisiae strain CHY1011, Y2: Saccharomyces cerevisiae strain ZP541)을 이용한 발효물의 총 페놀 및 플라보노이드 함량, 라디칼 소거능, tyrosinase 및 elastase 저해 활성을 측정하여 끄라차이담의 향후 건강기능식품 및 화장품 등과 같은 산업원료 소재로서의 이용 가능성을 탐색하고자 하였다. 발효물별 추출 수율은 BS 발효물(56.41%)이 가장 높았으며 그다음으로 무발효군(49.21%), LC(48.75%), LP(48.28%), CU(47.12%) Y1(41.32%), Y2(39.93%) 발효물의 순서로 나타났다. 총 페놀 측정 결과 13.88~33.29 GAE ㎎/g의 함량을 나타내었고 BS를 이용한 발효물이 유의적으로 높았으며 총 플라보노이드 함량은 무발효군이 가장 높은 값(8.55 CE ㎎/g)을 나타내었으며 발효군에서는 BS(7.08 CE ㎎/g)가 가장 높았고 CU(5.65 CE ㎎/g), Y1(4.54 CE ㎎/g), Y2(4.20 CE ㎎/g), LC(3.51 CE ㎎/g), LP(3.50 CE ㎎/g)의 순서로 높은 함량을 나타내었다. DPPH 라디칼 소거능 측정 결과 IC50 값이 BS 발효물에서 0.56 ㎎/mL로 가장 활성이 높았고 무발효군(0.68 ㎎/mL), CU(0.87 ㎎/mL), Y1(1.38 ㎎/mL), LP(1.72 ㎎/mL), LC(1.84 ㎎/mL), Y2(1.95 ㎎/mL) 발효물의 순서로 높게 나타났으며 모든 시료에서 유의적 차이를 보였다. ABTS 라디칼 소거능 측정 결과 IC50 값이 무발효군에서 1.14 ㎎/mL로 가장 높았고 발효물 중에서는 BS(1.46 ㎎/ mL)가 가장 높았으며 CU(1.70 ㎎/mL), Y1(2.16 ㎎/mL), Y2(2.89 ㎎/mL), LP(3.17 ㎎/mL), LC(3.38 ㎎/mL)의 순서로 높게 나타났다. 이때 DPPH 라디칼 및 ABTS 라디칼 소거능은 총 플라보노이드 함량이 증가할수록 소거능이 증가하는 경향을 보였으며, 이는 끄라차이담의 주요 성분인 methoxyflavone이 유효성분으로서 항산화 활성에 큰 영향을 미친것으로 생각된다. 끄라차이담 발효물의 FRAP 측정 결과 무발효군의 FRAP value(1.13 mM)가 유의적으로 가장 높은 활성을 나타내었다. Tyrosinase 저해활성 측정 결과 29.29~47.00%의 저해 활성을 나타내었으며 CU 발효물이 가장 높은 수치를 보였다. Elastase 저해능 측정 결과 39.93~56.41%로 나타났으며 이 중 BS 발효물이 유의적으로 가장 높았다. 상관관계 분석 결과 총 페놀 함량은 DPPH 라디칼 소거능 및 elastase 저해활성과 비교적 높은 상관관계가 있는 것으로 확인되었다. 총 플라보노이드 함량 또한 항산화 활성과 매우 높은 상관성을 나타내었으며 tyrosinase 및 elastase 저해활성과도 양의 상관관계를 나타내었다. 이상의 연구 결과 끄라차이담을 발효시킨 경우 균주 중 Bacillus subtilis를 사용하는 것이 우수한 항산화 활성을 가지는 것으로 생각되며 끄라차이담의 발효물은 tyrosinase 및 elastase 저해 효과가 있어 기능성 식품 및 화장품으로서 개발 가능성이 있을 것으로 생각된다.

The present study aimed to evaluate the cognitive experience associated with frequency and intensity by presenting subjects with vibrational stimuli of eight frequencies (10, 50, 100, 150, 200, 225, 250, and 300 Hz) and three intensities (Level 1: 0.25 G, Level 2: 0.38 G, Level 3: 1.3 G). The study participants were right-handed healthy adults (13 male subjects aged 23.2 years ± 0.8 and 7 female subjects aged 22.3 years ± 1.5) with normal cognitive function. The trials consisted of a stimulation phase (0.1 s) and a rest phase (6 s). After all types of stimuli were presented over five trials, a subjective evaluation was completed. As a result, the cognitive characteristic ‘weak’ was associated with the low frequency band of all intensity levels, while ‘strong’ was associated with an increase in vibration frequency and intensity. In addition to ‘weak’ and ‘strong’, the characteristic ‘vibrating’ was associated with frequencies above 100 Hz for all intensities. There were differences in cognitive experience, such as ‘thick’, ‘blunt’, and ‘heavy,’ between 100 and 150 Hz based on the level of intensity. In high frequency vibrations, between 200 and 300 Hz, the main characteristics changed to ‘fast’, ‘shallow’, and ‘light’ according to the intensity level. In this study, it was possible to derive cognitive experiences describing weight, unevenness, and thickness at specific intensities and frequencies in addition to the characteristics ‘weak’ and ‘strong’, which are typically associated with stimulus strength and frequency. If more diverse tactile properties can be derived through more detailed manipulations of stimulus intensity and frequency, complex linguistic information can then be associated with direct touch.

This study explores the subjective use of adjectives to verbally communicate vibrotactile stimulation across multiple frequencies. In total, nine different vibrotactile stimulus frequencies (10-300 Hz) were utilized, and subjective evaluation methods, which involved adjectives, were used to assess the sensory representations of the participants (18 healthy male participants; mean age, 22.9 years; standard deviation, 3.5). Sensory terms such as 'slow,' 'protruding,' and 'thick' were used as representative expressions to describe low-frequency (10-100 Hz) vibrotactile stimulations, while 'fast,' 'shallow,' and 'tickly' were used to describe high-frequency (225-300 Hz) vibrotactile stimulations. At the frequencies of 150 and 200 Hz, no characteristic word was found because there was no difference in subjective evaluation scores from other low or high frequencies. The results suggest that vibrotactile stimulation at different frequencies induce diverse sensory representations, owing to not only the motion and shape of the stimuli but also the subjective responses of the perceivers. The results of this study could be utilized in developing affective haptic devices in the future.

This study aims to use functional magnetic resonance imaging (fMRI) to assess the effective connectivity between the regions of the brain activated when driving and performing a secondary task (addition task). The subjects used an MR-compatible driving simulator ㅊ to manipulate the driving wheel with both hands and control the pedals (accelerator and brake) with their right foot as if they were driving in an actual environment. Effective connectivity analysis was performed for three regions of the right and the left hemispheres with the highest z-scores, and six of the regions of the entire brain (right and left hemisphere) activated during driving by dynamic causal modeling (DCM). In the right hemisphere, a motor control pathway related to movement control for driving performance was discovered, in the left hemisphere, the pathways in the regions related to movement control for driving performance, starting with the region associated with the secondary task, were discovered. In the whole brain, connectivity was discovered in each of the right and left hemispheres. The motor network of declarative memory, which is the connectivity of the right thalamus, left lingual gyrus, and right precentral gyrus, was worth noting. These results seem meaningful, as they demonstrate the connectivity associated with the control of voluntary movement related to memory from human experience, although limited to driving tasks.

[Purpose] Stroke survivors exhibit abnormal pelvic motion and significantly deteriorated gait performance. Although the gait of stroke survivors has been evaluated at the primary level pertaining to ankle, knee, and hip motions, secondary deviations involving the pelvic motions are strongly related to the primary level. Therefore, the aim of this study was to identify the kinematic differences of the primary and secondary joints and to identify mechanism differences that alter the gait performance of stroke survivors. [Subjects and Methods] Five healthy subjects and five stroke survivors were recruited. All the subjects were instructed to walk at a self-selected speed. The joint kinematics and gait parameters were calculated. [Results] For the stroke survivors, the range of motion of the primary-joint motions were significantly reduced, and the secondary-joint motions were significantly increased. Additionally, for the healthy subjects, the primary joint kinematics were the main factors ensuring gait performance, whereas for the stoke survivors, the secondary-joint motions were the main factors. [Conclusion] The results indicate that while increasing the range of motion of primary-joint movements is the main target to achieve, there is a strong need to constrain and support pelvic motions in order to improve the outcome of gait rehabilitation.

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible.

In this study, we measured neuronal activation in the primary somatosensory area (S1) and Brodmann area 3 (BA3) using 3T functional magnetic resonance imaging (fMRI) while presenting a 250-Hz high-frequency vibrational stimulus to each of three phalanges (distal, intermediate, and proximal) of four fingers of the right hand (index, middle, ring, and little). We compared the nerve activation area between each finger and each phalange. Ten healthy male college students (26.6 &plusmn, 2.5 years old) participated in this study. One session consisted of three blocks: a rest (30 s), stimulation (30 s), and response phase (9 s). In the rest phase, the vibrational stimulus was not presented. In the stimulation phase, the vibrational stimulation was presented at any one of the three phalanges of the selected finger. In the response phase, subjects were instructed to press a button corresponding to the phalange that they thought had received the vibration. The subtraction method was used to extract the activation area. The activation area in the S1 was the largest when the little finger was stimulated (for the finger comparison), and largest when the second phalange was stimulated (for the phalange comparison). The BA3 showed similar trends, and there was no statistically significant difference.

The CD133 antigen, also known as prominin-1, is a glycoprotein that specifically localizes to plasma membrane protrusions. The precise function of CD133 remains unknown, but it is expressed in various progenitor cells including those derived from the neural and hematopoietic system, as well as different tissues. In the adult mouse brain, CD133 is highly expressed in white matter. Here, we performed immunohistochemical staining and electron microscopy to demonstrate that mice lacking CD133 (CD133-/-) exhibit decreased myelin in the corpus callosum, the largest white matter tract in the brain. Hypomyelination in CD133-/- mice was associated with fewer oligodendrocyte progenitor cells and mature oligodendrocytes. Behavioral analyses revealed that significantly impaired object recognition memory and altered Y-maze performance by CD133-/- mice compared with wild-type mice, suggesting perturbed cognitive performance. These results suggest that CD133 regulates myelination and understanding the underlying molecular mechanisms may guide the development of novel therapeutic strategies for diseases characterized by myelin deficiency.

The purpose of this study was to examine the actual state of injuries experience and safety accident prevention in dental hygienists. This study surveyed the actual state of injuries experience caused by apparatus and materials through a self-administered survey of 366 dental hygienists. Statistical analysis was performed using PASW Statistics 18.0. Frequency, chi-square test, t-test, one-way ANOVA were applied in this analysis. The results were as follows: Out of the 307 subjects (83.9%) experienced injuries in the last 6 months, and 294 subjects (80.3%) chose the stab as the most frequent type of injuries experience and it was followed by incised wound, scratch and burn. In relation to the differences in injuries experience depending on general characteristics, there were significant differences depending on the age, career, position, dental treatment (p< 0.001) and the education (p

In this study, we examined the possibility and perceptual response characteristics of tactile sense induced by laser stimulation to the finger with different laser energy densities through human response experiments. 15 healthy adult males and 4 healthy adult females with an age of 22.6 ± 2.2 years were tested. A frequency-doubled Q-switched laser was used with a wavelength of 532 nm and a 5 ns pulse width. The experimental trial spanned a total of 30 s and included a rest phase (19 s), a stimulation phase (7 s), and a response phase (4 s). During the rest phase, subjects kept their fingers comfortable. During the stimulation phase, one of three types of laser energy density (13.5, 16.6, 19.8 mJ/cm 2 ) or a sham stimulation was used to irradiate the distal phalanx on the right index finger. During the response phase, the cognitive response to the laser stimulation was recorded by a PC by pressing the response button. The confusion matrix was configured to evaluate the possibility that the tactile sense was caused by the laser. In addition, changes in the response characteristics were observed according to three types of laser energy densities. From the analysis of the confusion matrix, the accuracy and sensitivity were not high. In contrast, precision and specificity were found to be high. Furthermore, there was a strong positive correlation between the laser irradiation and tactile perception, indicating that tactile sense can be induced using a laser in a mid-air manner. In addition, it was found that as the laser energy density increased, the tactile perception possibility also increased.

The present study compared event-related potential (ERP) patterns for two stimuli types, puff and suction, by applying these stimuli to the fingers; ERP patterns for the two stimuli were compared at C3, an area related to somatosensory perception, and at FC5, an area related to motor function. Participants were 12 healthy males in their 20s (mean age=23.1±2.0 years). One session consisted of a Control Phase (3s), a Stimulation Phase (3s), and a Rest Phase (9s). During the Stimulation Phase, a 4-psi suction or puff stimulus was applied to the first joint of the right index finger. After completion of the session, a subjective magnitude test was presented. In all phases, electroencephalography signals were recorded. We extracted maximum positive amplitude and minimum negative amplitude as well as relevant latency values for C3 and FC5 signals. Suction and puff stimuli had similar subjective magnitude scores. For both C3 and FC5, the maximum and minimum amplitude latency was reached earlier for the suction stimulus than for the puff stimulus. In conclusion, when suction and puff stimuli of the same intensity were applied to the fingers, the suction stimulus caused a more sensitive response in the somatosensory area (C3) and motor area (FC5) than did the puff stimulus.

Dopaminergic systems play a major role in reward-related behavior and dysregulation of dopamine (DA) systems can cause several mental disorders, including depression. We previously reported that dopamine D2 receptor knockout (D2R−/−) mice display increased anxiety and depression-like behaviors upon chronic stress. Here, we observed that chronic stress caused myelin loss in wild-type (WT) mice, while the myelin level in D2R−/− mice, which was already lower than that in WT mice, was not affected upon stress. Fewer mature oligodendrocytes (OLs) were observed in the corpus callosum of stressed WT mice, while in D2R−/− mice, both the control and stressed group displayed a decrease in the number of mature OLs. We observed a decrease in the number of active β-catenin (ABC)-expressing and TCF4-expressing cells among OL lineage cells in the corpus callosum of stressed WT mice, while such regulation was not found in D2R−/− mice. Administration of lithium normalized the behavioral impairments and myelin damage induced by chronic stress in WT mice, and restored the number of ABC-positive and TCF4-positive OLs, while such effect was not found in D2R−/− mice. Together, our findings indicate that chronic stress induces myelin loss through the Wnt/β-catenin signaling pathway in association with DA signaling through D2R.

This study was conducted to identify characteristics of the perceptual threshold level and electroencephalogram (EEG) responses to vibrotactile stimulations at various high frequencies, and to examine the possibility of distinguishing vibrotactile stimulations by frequency through such response characteristics. The vibrotactile stimulations of six frequencies (150, 200, 225, 250, 275 and 300 Hz) were exerted on the first joint of the right index finger. The perceptual threshold level was defined as the first minimum perceived intensity when the intensity stimulation was exerted step by step at each vibration frequency. EEG response characteristics were investigated by examining a single index corresponding to the peak or area of event-related desynchronization/synchronization (ERD/ERS) and seven specific indices derived by combining the single ERD/ERS indices. There was a significant difference in the perceptual threshold level across different frequencies. Specifically, the differences in vibration stimulus between 150 Hz and 200 Hz, and between 150 Hz and 225 Hz were significant. Of the EEG response characteristics, the single index of the peak or area of ERD/ERS did not show a significant difference by frequency. However, (ERS−ERD), ERD × (ERS−ERD), and ERS × (ERS−ERD) showed a significant difference between vibration stimulations at 150 Hz and 200 Hz, and between vibration stimulations at 150 Hz and 225 Hz, among the specific indices combined using the peak values of ERD/ERS. Furthermore, ERS × (ERS−ERD) showed a significant difference between 150 Hz and 225 Hz, and between 225 Hz and 275 Hz among the specific indices combined using the area of ERD/ERS. The perceptual threshold level and the specific indices of ERD/ERS suggested in the present study can be used as quantitative measurement indices to distinguish high-frequency vibration stimulation.

Background Several studies have used functional magnetic resonance imaging (fMRI) to show that neural activity is associated with driving. fMRI studies have also elucidated the brain responses associated with driving while performing sub-tasks. It is important to note that these studies used computer mouses, trackballs, or joysticks to simulate driving and, thus, were not comparable to real driving situations. In order to overcome these limitations, we used a driving wheel and pedal equipped with an MR-compatible driving simulator (80 km/h). The subjects drove while performing sub-tasks, and we attempted to observe differences in neuronal activation. Methods The experiments consisted of three blocks and each block consisted of both a control phase (1 min) and a driving phase (2 min). During the control phase, the drivers were instructed to look at the stop screen and to not perform driving tasks. During the driving phase, the drivers either drove (driving only condition) or drove while performing an additional sub-task (driving with sub-task condition) at 80 km/h. Results Compared to when the drivers were focused only on driving, when the drivers drove while performing a sub-task, the number of activation voxels greatly decreased in the parietal area, which is responsible for spatial perception. Task-performing areas, such as the inferior frontal gyrus and the superior temporal gyrus, showed increased activation. Performing a sub-task simultaneously while driving had affected the driver’s driving. The cingulate gyrus and the sub-lobar region (lentiform nucleus, caudate, insula, and thalamus), which are responsible for error monitoring and control of unnecessary movements (e.g., wheel and pedal movements), showed increased activation during driving with sub-task condition compared to driving only condition. Conclusions Unlike simple driving simulators (joysticks, computer mouses, or trackballs) used in previous research, the addition of a driving wheel and pedals (accelerator and brake) to the driving simulator used in this study closely represents real driving. Thus, the number of processed movements was increased, which led to an increased number of unnecessary movements that needed to be controlled. This in turn increased activation in the corresponding brain regions.

This study investigated the effect of aging on visuospatial cognition performance and regional brain activation between 20s and 40s. Eight right-handed male college students in their twenties and six right-handed male adults in their forties who were graduated from college participated in the study. A visuospatial task was presented while brain images were acquired by a 3T functional Magnetic Resonance Imaging (fMRI) system. Accuracy rate of visospatial tasks was calculated. Using the subtraction procedure, activated areas in the brain during visuospatial tasks were color-coded by t-score. The double subtraction method was used to analyze the effect of the aging between the two age groups (i.e., 20s vs. 40s). Compared to the 40s the 20s showed higher visuospatial performance. The cerebellum, occipital lobe, parietal lobe, and frontal lobe were almost similarly activated for two age groups. Increased brain activations, however, were observed in some regions in the parietal and superior frontal lobes at 20s compared to 40s. There was more activation observed in some regions in the middle frontal and right inferior frontal lobes at 40s compared to 20s. These results suggest that the lowering of visuospatial performance with aging between 20s and 40s was correlated to the decrease of activation area in the parietal lobe and the change of activation area in the frontal lobe.

In this study, a Magnetic Resonance (MR)-compatible finger stimulator was developed that can display pressure and heat stimulation simultaneously. The developed finger stimulator consists of three parts: a main controller, drive units, and tactors. The main controller controls stimulation parameters such as stimulation intensity and time. The drive units operate pressure and heat tactors in response to commands from the main controller. The tactors display various pressure and heat stimulation quantitatively and simultaneously. The developed stimulator has many advantages in overall system, stimulation control, and tactor aspects. The new stimulator operated stably in MR circumstance without affecting MR images. Therefore, it can be used for the various intra-and inter-finger functional magnetic resonance imaging (fMRI) studies on pressure and heat sensation.

The purpose of this study is to provide information for the protection of Korean homecare patients with senile dementia by investigating accident cases using a survey. With the survey of accident cases, the caregivers of 55 Korean homecare patients with senile dementia (75.9 ± 7.0 years) were administered the short form of the Samsung Dementia Questionnaire (S-SDQ) and an activities of daily living (ADL) test. Twelve risk elements were extracted. The order of frequency of occurrence from highest to lowest was "egress," "fall," "violence," "collision," "gas accident," "slip," "faucet misuse," "overeating," "drop," "discharge," "weird eating," and "self-injury." The percentage of risk elements resulting in physical harm was 40.1% across all risk elements. The risk elements resulting in the most physical harm were "fall," "collision," "slip," and "drop," respectively. Regarding the location of occurrence of risk elements, risk elements resulting in physical harm showed no significant differences between indoors and outdoors. Some risk elements, such as "egress," "fall," and "gas accident" happened concurrently with more than four other elements, while "collision," "drop," and "violence" happened together with more than two other elements. "Slip" happened significantly more often in the low ADL score group, while "gas accident" happened significantly more often in the high ADL score group. This study provides basic information about monitoring factors to protect senior homecare patients with senile dementia.

Earlier, we examined the positive effects of hyperoxic air on the cognitive ability of intellectually and developmentally disabled people (IDDP). In this study, the correlation between cognitive performance in the visual matching task and heart rate (HR) was investigated under normal air conditions. Eighteen men (mean age 28.7 ± 5.0 year) and 22 women (mean age 35.5 ± 6.9 year) with an assessed disability level of 2.3 ± 0.6 participated. The experiment consisted of three phases, a total of 7 min, including the rest (3 min), control (2 min), and visual matching task (2 min) phases. The HR in the visual matching task phase increased, compared to that in the rest and control phases. The cognitive ability in the visual matching task correlated with the HR values; the response time showed a negative correlation with the HR, while the accuracy rate showed a positive correlation. Thus, adaptive changes in cardiovascular regulation probably related to cognitive efforts and emotional excitation is a noticeable factor influencing brain supply with oxygen in IDDP (similarly to those in healthy people). The result of this study agrees with the earlier obtained indications that hyperoxic air can positively affect the cognitive performance in IDDP.

This study measured the cerebellar volume of normal male adults in 20s with magnetic resonance imaging (MRI) and analysed the relationship between cerebellar volume and various psychological parameters. The cerebellar volume of 58 males (mean age, 24.0-2.8 years) was measured using MRI. The Symptom Checklist-90-R (SCL-90-R) and the Component of Type A Behavior tests were performed. Using linear regression analysis, the relationship between cerebellar volume and psychological parameters was analysed. As phobic anxiety and ambition increased, cerebellar volume of normal male subjects in 20s decreased. This study showed that for even normal male adults, there exists a possible relationship between various psychological parameters and cerebellar volume.

This study investigated the changes of cerebral activation and lateralization due to the cognition of three driving speeds in comparison to a reference driving speed using functional magnetic resonance imagingfMRI�. A driving video as a visual stimulation source was recorded with four different driving speeds in a real driving situation. The experiment consisted of three blocks and each block included a one-minute control phase and a one-minute stimulation phase. The activation area and the lateralization index were analyzed by subtracting high speed data from low speed data. Such areas as occipital, parietal and frontal lobes, which is related to visual cognition, high order visual and spatial attention (or vigilance), were activated due to the cognition of various driving speed differences. As the driving speed difference increased, the activation area increased in the areas related to spatial attention (or vigilance), such as the frontal lobe, however, changes of neuronal activation in the occipital and parietal lobes were inconsistent. As the driving speed difference increased, the absolute value of cerebral lateralization decreased. These results may provide some basic data for elucidating the brain- function mechanism related to the cognition of a various driving speed difference based on a realistic visual stimulation.

In this study, a tactile stimulator that could separately or simultaneously display the vibrotactile and pressure sense was developed. The developed system consisted of a control unit, a drive unit, and an actuator, and can be operated with PC or manually. This system quantitatively controls the stimulation parameters such as the stimulation intensity, duration, frequency, and stimulation type. A preliminary electroencephalogram (EEG) experiment for three types of stimulation (vibrotactile, pressure sense, vibrotactile + pressure sense) highlights that the system could be used in complex tactile cognitive studies. An event-related desynchronization (ERD) and synchronization (ERS) were measured at the area of C3 and C4 for all three types of stimulation, and a clear response was identified in the contralateral somatosensory area from the brain topology. Therefore, it is expected that this system could be widely used in single and complex human tactile cognition and perception studies for vibrotactile and pressure sensation.

This study investigated neuronal activation differences under two conditions: driving only and distracted driving. Driving and distraction tasks were performed using a Magnetic Resonance (MR)-compatible driving simulator with a driving wheel and pedal. The experiment consisted of three blocks, and each block had both a Rest phase (1 min) and a Driving phase (2 min). During the Rest phase, drivers were instructed to simply look at the stop screen without performing any driving tasks. During the Driving phase, each driver was required to drive at 110 km/h under two conditions: driving only and driving while performing additional distraction tasks. The results show that the precuneus, inferior parietal lobule, supramarginal gyrus, middle frontal gyrus, cuneus, and declive are less activated in distracted driving than in driving only. These regions are responsible for spatial perception, spatial attention, visual processing and motor control. However, the cingulate gyrus and sub-lobar regions (lentiform nucleus and caudate), which are responsible for error monitoring and control of unnecessary movement, show increased activation during distracted driving compared with driving only.

Thoracic paravertebral sympathetic postganglionic neurons (tSPNs) comprise the final integrative output of the distributed sympathetic nervous system controlling vascular and thermoregulatory systems. Considered a non-integrating relay, what little is known of tSPN intrinsic excitability has been determined by sharp microelectrodes with presumed impalement injury. We thus undertook the first electrophysiological characterization of tSPN cellular properties using whole-cell recordings and coupled results with a conductance-based model to explore the principles governing their excitability in adult mice of both sexes. Recorded membrane resistance and time constant values were an order of magnitude greater than values previously obtained, leading to a demonstrable capacity for synaptic integration in driving recruitment. Variation in membrane resistivity was the primary determinant controlling cell excitability with vastly lower currents required for tSPN recruitment. Unlike previous microelectrode recordings in mouse which observed inability to sustain firing, all tSPNs were capable of repetitive firing. Computational modeling demonstrated that observed differences are explained by introduction of a microelectrode impalement injury conductance. Overall, tSPNs largely linearly encoded injected current magnitudes over a broad frequency range with distinct subpopulations differentiable based on repetitive firing signatures. Thus, whole-cell recordings reveal tSPNs have more dramatically amplified excitability than previously thought, with greater intrinsic capacity for synaptic integration and with the ability for maintained firing to support sustained actions on vasomotor tone and thermoregulatory function. Rather than acting as a relay, these studies support a more responsive role and possible intrinsic capacity for tSPNs to drive sympathetic autonomic function.

For this study, we developed a simple pressure and heat stimulator that can quantitatively control pressure and provide heat stimulation to intra- and interdigit areas. The developed stimulator consists of a control unit, drive units, and tactors. The control unit controls the stimulation parameters, such as stimulation types, intensity, time, and channel, and transmits a created signal of stimulation to the drive units. The drive units operate pressure and heat tactors in response to commands from the control unit. The pressure and heat tactors can display various stimulation intensities quantitatively, apply stimulation continuously, and adjust the stimulation areas. Additionally, they can easily be attached to and detached from the digits. The developed pressure and heat stimulator is small in total size, easy to install, and inexpensive to manufacture. The new stimulator operated stably in a magnetic resonance imaging (MRI) environment without affecting the obtained images. A preliminary functional magnetic resonance imaging (fMRI) experiment confirmed that differences in activation of somatosensory areas were induced from the pressure and heat stimulation. The developed pressure and heat stimulator is expected to be utilized for future intra- and interdigit fMRI studies on pressure and heat stimulation.

In this study, functional magnetic resonance image (fMRI)-compatible movement measurement system was developed. The movement measurement system consisted of a sensor module with a three-axis accelerometer and a two-axis gyroscope, a modulator, and a demodulator. Velcro was used to attach the sensor module to a finger or wrist. Interactive effects in a human subject were tested by measuring fMRI and motion signals simultaneously. Images were obtained using the field echo planar imaging method using a 3 T MR scanner and the signal-to-noise ratio was calculated. The entire system can be made with low cost, and its direct implementation is available in a clinical MR scanner without any additional installation. Various kinematic variables, such as angle, acceleration, and jerk, can be measured and calculated by using the movement measurement system. Therefore, it is expected that this system could be used for the study of the relationship between various kinematic variables and brain function.

The somatotopic representation of the tactile stimulation on the finger in the brain is an essential part of understanding the human somatosensory system as well as rehabilitation and other clinical therapies. Many studies have used vibrotactile stimulations and reported finger somatotopic representations in the Brodmann area 3 (BA 3). On the contrary, few studies investigated finger somatotopic representation using pressure stimulations. Therefore, the present study aimed to find a comprehensive somatotopic representation (somatotopic map and inter- and intra-digit distance) within BA 2 of humans that could describe tactile stimulations on different joints across the fingers by applying pressure stimulation to three joints-the first (p1), second (p2), and third (p3) joints-of four fingers (index, middle, ring, and little finger). Significant differences were observed in the inter-digit distance between the first joints (p1) of the index and little fingers, and between the third joints (p3) of the index and little fingers. In addition, a significant difference was observed in the intra-digit distance between p1 and p3 of the little finger. This study suggests that a somatotopic map and inter- and intra-digit distance could be found in BA 2 in response to pressure stimulation on finger joints.

Although more about the somatotopic mapping of fingers continues to be uncovered, there is lack of mapping attempts regarding the integration of within-finger and across-finger somatotopic coordinates in Broadmann area (BA) 3. This study aimed to address the issue by finding an inter-/intradigit somatotopic map with high-frequency (250 Hz) vibrotactile stimulation. Functional magnetic resonance imaging (fMRI) data were acquired while stimulation was applied to 3 phalanxes (distal [p1], intermediate [p2], and proximal [p3] phalanx) of 4 fingers (index, middle, ring, and little finger) for a total of 12 finger–phalanx combinations for a human. Inter-, intra-, and inter-/intradigit distances were calculated from peak activation coordinates in BA 3 for each combination. With regard to interdigit dimensions, the somatotopic coordinates proceeded in the lateral-to-medial direction for the index, middle, ring, and little fingers consecutively. This trend is comparable to that generated from low-frequency stimulation modalities (flutter stimulation). The somatotopic distances between fingers were greatest when p1 was compared across fingers. From an intradigit perspective, stimulation on p1, p2, and p3 yielded BA 3 peak coordinates aligned along the anterior-to-posterior and inferior-to-superior directions for all fingers. An inter-/intradigit map exhibited a radially propagating trend of distances calculated with respect to index p1 as a reference point; this provided an integrated view of inter- and intradigit somatotopies, which are traditionally discussed separately. We expect such an inter-/intradigit somatotopic map approach to contribute in generating a comprehensive somatotopic model of fingers.

The study investigated differences in cognitive ability and hippocampal volume between groups of patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), and healthy control (HC) subjects, and explored the relationship between cognitive ability and hippocampal volume. Among the sub-tests of Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), the Boston naming test score decreased in the order HC, aMCI, and AD. The hippocampal volumes of subjects with AD and aMCI were relatively smaller than those of HC individuals. There were strongly positive correlations between hippocampal volume and the scores for the Boston naming test. Discriminant analysis identified the Boston naming test as having the highest level of discrimination among the variables used to differentiate the three groups (89.9%). In conclusion, the Boston naming test accurately differentiated the three groups and was correlated with hippocampal volume. These results will be helpful for choosing an accurate and economically feasible test method that efficiently differentiates the three groups.

Aim: This study investigated the correlation between response time of the 1-back task and changes of blood oxygen saturation (SpO2) by supplying three different levels of oxygen (21%, 1 L/min; 93%, 1 L/min; 93%, 5 L/min) in the elderly. Methods: A total of 17 older adults (mean age 72.9 ± 4.7 years) participated in the experiment. A 1-back task was used as a cognitive task. The experiment consisted of three phases, which included the adaptation phase (3 min) after oxygen administration, the control phase (2 min) that maintained a stable condition before the task, and the task phase (2 min) where the 1-back task was carried out. SpO2 was measured during each phase. Results: As concentration level and supply of oxygen increased, SpO2 increased and response time of the 1-back task decreased. Conclusion: Highly concentrated oxygen administration can increase SpO2 in the elderly and an increase in cognitive performance, such as a decrease in response time, can be observed. Geriatr Gerontol Int 2013; 13: 384–387.

Aims: To measure the orbital volume of normal Korean people in two different age groups (subjects were in their 20s or 40s), and analyze the differences of orbital volume with respect to age and gender. In addition, to analyze correlation between body parameters (height and weight) and the orbital volume. Methods: Magnetic resonance imaging (MRI) data were acquired for a total of 143 subjects, consisting of 71 subjects in their 20s (32 males and 39 females) and 72 subjects in their 40s (30 males and 42 females). Two-way ANOVA was used to analyze how orbital volume changes with respect to gender and age. A multiple regression analysis was performed to investigate the correlation between body parameters and the orbital volume. Results: The orbital volume of subjects in their 20s was larger than that of subjects in their 40s, and the volume was larger in men than in women. As age increased, the decrease in the orbital volume of women was greater than that of men. While weight and height showed positive correlations with orbital volume in male and female subjects in their 20s, respectively, weight showed a positive correlation with orbital volume in male and female subjects in their 40s. Conclusions: These results provide basic information about the effect of age, gender, and body parameters on orbital volume of Korean people in their 20s or 40s.

The dopamine D2 receptor (D2R) plays an important role in mesencephalic dopaminergic neuronal development, particularly coupled with extracellular signal-regulated kinase (ERK) activation. Wnt5a protein is known to regulate the development of dopaminergic neurons. We analyzed the effect of Wnt5a on dopaminergic neuron development in mesencephalic primary cultures from wild-type (WT) and D2R knock-out (D2R(-/-)) mice. Treatment with Wnt5a increased the number and neuritic length of dopamine neurons in primary mesencephalic neuronal cultures from WT mice, but not from D2R(-/-) mice. The effect of Wnt5a was completely blocked by treatment with D2R antagonist or inhibitors of MAPK or EGFR. Wnt5a-mediated ERK activation in mesencephalic neuronal cultures was inhibited by treatment of D2R antagonist and EGFR inhibitors in WT mice. However, these regulations were not observed for D2R(-/-) mice. Co-immunoprecipitation and displacement of [(3)H]spiperone from D2R by Wnt5a demonstrated that Wnt5a could bind with D2R. This interaction was confirmed by GST pulldown assays demonstrating that the domain including transmembrane domain 4, second extracellular loop, and transmembrane domain 5 of D2R binds to Wnt5a. These results suggest that the interaction between D2R and Wnt5a has an important role in dopamine neuron development in association with EGFR and the ERK pathway.

The purpose of this study was to investigate the central problem features of Korean patients with senile dementia and to prioritize the features according to risk to the patient with a view to the implementation of remote monitoring technologies. Twenty central problem features were extracted using factorial analysis. The frequency of violent language and confabulation, gathering, and repetition was significantly greater in female than in male patients with senile dementia. All central features, with the exception of abnormal sexual behavior and audiovisual deficits, differed in frequency between the normal elderly and the senile dementia patients and between patients with dementias of different severity. Judgment disorder was the greatest differentiating factor between the normal elderly and the patients with senile dementia. For dementia severity, memory disorder was the greatest differentiating factor of severe versus mild dementia. When risk to the patient was analyzed, problems of perception were identified as the problem features of highest priority.

The purpose of this study was to compare gait pattern and cognitive function among elderly patients with Alzheimer’s Disease (AD), elderly people with Mild Cognitive Impairment (MCI), and Healthy Controls (HC). Twenty three elderly patients participated: 10 AD (77.2±6.84 yrs), 7 MC I(72.9±6.28 yrs), and 6 HC (71.6±5.78 yrs). Gait and Cognitive function were collected using an accelerometer attached to the foot and the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease (CREAD-K), respectively. To compare differences in gait performance among groups, mean stride time, magnitude and structure of gait variability and ratio of low frequency and high frequency (LF/HF ratio) of stride time sequence were used in this study. Results showed that gait variables (mean stride time, LF/HF ratio of stride time) were useful for classification between MCI and HC. Cognitive function (T1, T3, T4, T6, and T8 of CREAD-K) represented the difference between AD and HC. This study may provide a foundation for future work on progression of dementia.

This study investigated differences in blood oxygen saturation() and heart rate(HR) according to flow rate, gender, and phase in males and females in their 60s when the supply of 93% highly concentrated oxygen administration was changed (1L/min, 3L/min, and 5L/min). It recruited totally 20 elderly subjects including 10 males( years) and 10 females ( years). The experiment consisted of three phages of Rest 1(5 min), Hyperoxia(10 min), and Rest 2(10 min), and [%] and HR[bpm] were measured during all phages. was higher in Hyperoxia phase supplied with highly concentrated oxygen than in Rest phases. Higher flow rate was associated with more increase in . HR was reduced in Hyperoxia phase compared to Rest phases. More supply of highly concentrated oxygen was associated with more decrease of HR. However, there were no differences in both and HR according to gender.

The purpose of this study was to analyze the skin conductance level (SCL) induced by unexpected situation which reflected the emotional and cognitional responses during driving. The participants included 57 college graduates; 28 males aged 24.5±1.3 with 2.3±1.5 years of driving experiences and 29 females aged 23.6±2.6 with 2.2±1.7 years of driving experience. Reaction time of brake, averaged SCL, maximum SCL, and rising time to maximum amplitude were measured. They were analysed according to condition (crash, non-crash) and gender (male, female). The reaction time of brake was more faster and averaged SCL was greater during non-crash condition than during crash condition. There were no significant differences between male and female drivers in the reaction time of brake and averaged SCL whether or not it crash. There were no significant differences between crash and non-crash conditions in the maximum SCL and rising time to maximum amplitude, but there were significant differences between male and female in them. These results support the hypothesis that averaged SCL is more related to cognitional response and maximum SCL and rising time to maximum amplitude are more related to emotional responses. Keywords: Unexpected situation, Skin conductance level, Cognitional and emotional responses, Crash and non-crash, Gender

The purpose of this study was to measure the average corpus callosum volume of normal Koreans (aged in their 20s or 40s) and to analyze the effects of gender, age, and body parameters, such as height and weight on corpus callosum size. Magnetic resonance brain images were recorded for 68 people in their 20s (29 men, 39 women) and 91 in their 40s (36 men, 55 women). Intracranial volume was calculated using cerebral size and corpus callosum volume was normalized by covariance method. To investigate the effect of gender and age on corpus callosum volume, two-way analysis of variance, which used gender (two levels) and age (two levels) as independent variables, was employed. Multiple regression analysis was carried out to investigate the effect of body parameters, such as height and weight, according to the age and gender on the changes in corpus callosum volume. The average corpus callosum volume of Korean men (11.09 cm(3)) was larger than that of Korean women (9.61 cm(3)). There was no significant difference in corpus callosum volume between 20s (10.43 cm(3)) and 40s (10.12 cm(3)). There was a positive relationship between body weight and corpus callosum volume for 20s, but not for 40s.