Human Brain Mapping of Visual Script Familiarity between Phonological and Logographic Language: 3 T Functional MRI Study

Kim, Nambeom,Kim, Jongho,Kang, Chang-Ki,Park, Chan-A,Lim, Mi-Ra,Kim, Young-Bo,Bak, Byung-Gee Hindawi 2017 BioMed research international Vol.2017 No.-

<P>Neurolinguistic circuitry for two different scripts of language, such as phonological scripts (PhonoS) versus logographic scripts (LogoS) (e.g., English versus Chinese, resp.), recruits segregated neural pathways according to orthographic regularity (OrthoR). The purpose of this study was to identify the effect of VSF for cortical representation according to different OrthoR to represent Hangul versus Hanja as PhonoS versus LogoS, respectively. A total of 24 right-handed, native Korean undergraduate students with the first language of PhonoS and the second language of LogoS were divided into high- or low-competent groups for L2 of LogoS. The implicit word reading task was performed using Hanja and Hangul scripts during functional magnetic resonance imaging (fMRI) acquisition. Fluctuations of fMRI BOLD signal demonstrated that the LogoS was associated with the ventral pathway, whereas PhonoS was associated with the dorsal pathway. By interaction analysis, compared with high-competent group, low-competent group showed significantly greater activation for Hanja than for Hangul reading in the right superior parietal lobule area and the left supplementary motor area, which might be due to neural efficiency such as attention and cognition rather than core neurolinguistic neural demand like OrthoR processing.</P>

Language Switching Between Hanja and Hangeul : An fMRI Experiment

( Nambeom Kim ),( Kyung Jin Lee ),( Chang Ki Kang ),( Young Bo Kim ),( Yeong Bae Lee ) 한국감성과학회 2016 춘계학술대회 Vol.2016 No.-

The Influence of Life Stress and Sleep Disturbance on White Matter Integrity

Kim Minjeong,Lee Jiye,Kim Nambeom,Hwang Yunjee,Lee Kyung Hwa,Lee Jooyoung,Lee Yu Jin,Kim Seog Ju 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.5

Objective This study investigated whether sleep and stress mutually interact to induce changes in white matter integrity.Methods Diffusion tensor imaging (DTI) was conducted on 36 participants (male=22, female=14; mean age=38.33±12.78 years). Participants were divided into three groups depending on their sleep quality and stress levels: poor sleepers with stress, poor sleepers without stress, and good sleepers. Sleep quality and stress level were evaluated using the Pittsburgh Sleep Quality Index and the Life Experiences Survey, respectively. Fractional anisotropy (FA) values were calculated employing DTI tractography.Results After controlling for age and sex, poor sleepers with stress exhibited a lower FA of the left inferior cerebellar peduncle (ICP) than did poor sleepers without stress (t=2.81, p=0.02). Poor sleepers without stress showed a higher FA of the right middle longitudinal fasciculus (MdLF) than did good sleepers (t=3.35, p=0.006).Conclusion The current study reports the effects of sleep, stress, and their interaction on the white matter integrities of the ICP and MdLF. ICP change seems to be associated with sleep disturbances related to stress, while MdLF change would be associated with sleep disturbances unrelated to stress.

The Cortical Representation of Visual Script Familiarity: fMRI Experiment

( Nambeom Kim ),( Yeong Bae Lee ),( Young Bo Kim ),( Chang Ki Kang ) 한국감성과학회 2015 추계학술대회 Vol.2015 No.-

It has been a great interest of the extent or degree to which visual script familiarity affects cortical representation. Because an alienation of the Hanja writing system was caused by the Hangul-only policy promoted by the South Korean government in the mid-1970s, Korean younger generation has dichotomized by Hanja familiarity. Therefore, the purpose of this study was to examine the script familiarity of Hanja and then identify the cortical foci related to the script familiarity. In this study, we recruited low familiarity group (LF) and high familiarity group (HF) by their Hanja competency, who performed fMRI reading experiment with two-letter Hanja scripts and two-letter Hangul scripts. We hypothesized that cortical representation between LF and HF during Hanja reading compared to Hangul reading would show a different pattern reflecting the script familiarity. fMRI results indicated that the LF group showed greater involvement of the right hemisphere including the right superior parietal lobule and supplementary motor area, whereas the HF group showed greater activation bilateral caudate nuclei. In conclusion, less familiar script showed greater right hemisphere lateralization during script processing, which is presumably engaged in increased general cognitive demand due to neural efficiency whereas higher familiar script was shown to engage in that of controlling language, presumably literacy skills. Acknowledgement This work was supported by the Gachon University research fund (GCU-2015-5030).

Effect of Lifetime Cognitive Reserve on Functional Connectivity in the Default Mode Network at the Predementia Stage

Soo Kyun Woo,Jae Myeong Kang,Nambeom Kim,Sook Young Lee,Sangsoon Kim,Da Jeong Kim,Chang-Ki Kang,Jun-Young Lee,Seong-Jin Cho 대한노인정신의학회 2021 노인정신의학 Vol.25 No.2

Objective: Cognitive reserve (CR) protects against cognitive decline by utilizing functional connectivity (FC) in the brain, such as the default mode network (DMN). We studied whether CR in individuals with predementia would correlate with better cognition and increased DMN FC in the resting brain. Methods: Fifty-four participants with subjective cognitive decline or mild cognitive impairment completed the Cognitive Reserve Index (CRI) questionnaire, and underwent a comprehensive neuropsychological test battery and resting state functional magnetic resonance imaging. Correlation and regression analyses for clinical variables and seed-to-voxel analyses of CR-related FC in the DMN were conducted. Results: CRI total (β=0.42, p=0.001), education (β=0.39, p=0.001), and leisure time (β=0.33, p=0.009) predicted the Mini- Mental State Examination. The CRI education predicted verbal memory recall (β=0.32, p=0.017), confrontational naming (β=0.57, p<0.001), and phonemic fluency (β=0.43, p=0.004). In the DMN in the resting brain, the CRI total correlated with increased FC, based on the posterior cingulate to both lateral parietal cortices. Conclusion: In individuals with predementia, comprehensive CR correlated with an enhanced network in the DMN in the resting state. These results may support the neural correlate of CR during the initial stage of cognitive decline.

주성분분석을 이용한 C[11]-PIB imaging 영상분석

김남범,신귀순,안성민,Kim, Nambeom,Shin, Gwi Soon,Ahn, Sung Min 대한핵의학기술학회 2015 핵의학 기술 Vol.19 No.1

Purpose Principal component analysis (PCA) is a method often used in the neuroimagre analysis as a multivariate analysis technique for describing the structure of high dimensional correlation as the structure of lower dimensional space. PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of correlated variables into a set of values of linearly independent variables called principal components. In this study, in order to investigate the usefulness of PCA in the brain PET image analysis, we tried to analyze C[11]-PIB PET image as a representative case. Materials and Methods Nineteen subjects were included in this study (normal = 9, AD/MCI = 10). For C[11]-PIB, PET scan were acquired for 20 min starting 40 min after intravenous injection of 9.6 MBq/kg C[11]-PIB. All emission recordings were acquired with the Biograph 6 Hi-Rez (Siemens-CTI, Knoxville, TN) in three-dimensional acquisition mode. Transmission map for attenuation-correction was acquired using the CT emission scans (130 kVp, 240 mA). Standardized uptake values (SUVs) of C[11]-PIB calculated from PET/CT. In normal subjects, 3T MRI T1-weighted images were obtained to create a C[11]-PIB template. Spatial normalization and smoothing were conducted as a pre-processing for PCA using SPM8 and PCA was conducted using Matlab2012b. Results Through the PCA, we obtained linearly uncorrelated independent principal component images. Principal component images obtained through the PCA can simplify the variation of whole C[11]-PIB images into several principal components including the variation of neocortex and white matter and the variation of deep brain structure such as pons. Conclusion PCA is useful to analyze and extract the main pattern of C[11]-PIB image. PCA, as a method of multivariate analysis, might be useful for pattern recognition of neuroimages such as FDG-PET or fMRI as well as C[11]-PIB image.

The influence of long time 4G hypergravity in vestibular system

Gyu cheol HAN(한규철),Mi joo KIM,Yu Jin MIN,Dongju LEE,Nambeom KIM 한국항공우주의학협회 2016 항공우주의학 학술대회 Vol.2016 No.5

Intermixed structure of voxels with different hemispheric characteristics in the fusiform face area

Choi, Uk-Su,Sung, Yul-Wan,Choi, Sang-Han,Kim, Nambeom,Kim, Young-Bo,Cho, Zang-Hee,Ogawa, Seiji Lippincott Williams Wilkins, Inc. 2013 NEUROREPORT - Vol.24 No.2

The fusiform face area, a high-level visual area, is pivotal in processing facial information. This area receives inputs from the left and right visual fields unlike the primary visual area, which only receives inputs from its contralateral visual field. Response of the fusiform face area to ipsilateral stimulation depends on the signals crossing over at the corpus callosum. We investigated the distribution of voxel-wise activation to determine whether ipsilateral-dominant voxels exist in the fusiform face area using high spatial resolution functional MRI at 7 T. We further examined the possible functional differences between ipsilateral-dominant and contralateral-dominant voxels. By unilateral visual field stimulation, we detected ipsilateral-dominant voxels in the right fusiform face area. Their distribution was spatially heterogeneous. We tested upright and inverted facial stimulation confined to unilateral visual fields and found that these ipsilateral-dominant voxels had a different functional nature from contralateral-dominant voxels.