시열과제 운동학습 시 집중연습과 분산연습이 P300 출현시기에 미치는 영향

권용현,이명희,Kwon, Yong-Hyun,Lee, Myoung-Hee 대한물리치료학회 2014 대한물리치료학회지 Vol.26 No.4

Purpose: The purpose of this study is to use P300 latency to determine whether methods of motor learning in terms of massed and distributed practice can affect motor sequential learning in healthy adults. Methods: Twenty-four healthy subjects participated in this study. They were randomly allocated into three groups: a 10 minute, a 12 hour, and a 24 hour group. In the SRT task, eight numbers were adopted as auditory stimuli. During an experiment, participants were instructed to press the matching key as quickly and accurately as possible when one of the eight numbers was presented randomly. The subjects practiced for three sessions, each of which comprised five blocks of 40 serial reaction time tasks. While they practiced during these three sessions, P300 latency was measured. The data were analyzed using ANCOVA. Results: The P300 latency of Fz, Cz, and Pz decreased in all groups except for the Fz area of the 10 min group. Overall, the P300 latency of the 10 min group showed a smaller decrease compared with the 12 hr and 24 hr groups. Statistically, no significant differences in the Fz and Cz areas were observed among the three groups. The P300 latency in the Pz area of the 10 min group showed a significantly smaller decrease compared with the other groups. Conclusion: These findings suggest that short-term sequential motor training can alter brain functions such as the P300 latency. We also found that better acquisition of a motor skill was obtained with distributed practice of a task than with massed practice.

정상 성인에서 경두개 직류 전류자극과 기능적 전기자극에 의한 대뇌피질의 활성화: 사례연구

권용현,권중원,박상영,장성호,Kwon, Yong-Hyun,Kwon, Jung-Won,Park, Sang-Young,Jang, Sung-Ho 대한물리치료학회 2011 대한물리치료학회지 Vol.23 No.1

Purpose: Recently, many studies have demonstrated that application of external stimulation can modulate cortical excitability of the human brain. We attempted to observe cortical excitability using functional magnetic resonance imaging (fMRI) during the application of transcranial direct current stimulation (tDCS) or functional electrical stimulation (FES). Methods: We recruited two healthy subjects without a history of neurological or psychiatric problems. fMRI scanning was done during? each constant anodal tDCS and FES session, and each session was repeated three times. The tDCS session consisted of three successive phases (resting phase: 60sec dummy cycle: 10sec tDCS phase: 60sec). The FES session involved stimulation of wrist extensor muscles over two successive phase (resting phase: 15sec FES phase: 15sec). Results: The average map of the tDCS and FES analyses showed that the primary sensory-motor cortex area was activated in all subjects. Conclusion: Our findings show that cortical activation can be induced by constant anodal tDCS and FES. They suggest that the above stimuli have the potential for facilitating brain plasticity and modulating neural excitability if applied as specific therapeutic interventions for brain injured patients.

경두개 직류전류 자극이 대뇌피질의 뇌 활성도에 미치는 영향

권용현,김중선,장성호,Kwon, Yong-Hyun,Kim, Chung-Sun,Jang, Sung-Ho 대한물리치료학회 2009 대한물리치료학회지 Vol.21 No.4

Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

능동 및 수동 운동과 기능적 전기자극에 의한 대뇌 피질의 활성화

권용현 ( Yong Hyun Kwon ),장성호 ( Sung Ho Jang ),한봉수 ( Bong Soo Han ),최진호 ( Jin Ho Choi ),이미영 ( Mi Young Lee ),장종성 ( Jong Sung Chang ) 한국전문물리치료학회 2005 한국전문물리치료학회지 Vol.12 No.2

CO2레이저와 5% Imiquimod 크림 병합요법으로 치료한 기저세포암

권용현 ( Yong Hyun Kwon ),남재희 ( Jae Hui Nam ),김태환 ( Tae Hwan Kim ),이가영 ( Ga Young Lee ),김원석 ( Won Serk Kim ),김계정 ( Kea Jeung Kim ) 대한피부과학회 2007 대한피부과학회지 Vol.45 No.11

Basal cell carcinoma is the most common skin cancer and surgical treatments like Mohs surgery have been accepted as ideal for it. Although surgical treatments are very effective, non-invasive treatments such as electrocauterization, cryosurgery, CO2 laser and topical 5-fluorouracil cream have been tried because patients need more simple procedures and better cosmetic results. Imiquimod is a Toll-like receptor 7 agonist and which acts as an immune response modifier by inducing several cytokines including interferon. Previously, many reports showed the usefulness of 5% imiquimod cream in treating basal cell carcinoma. However, some local adverse effects, long treatment time and limitation of deep penetration are problems to be resolved. We tried 5% imiquimod cream application after the removal of a visible basal cell carcinoma using CO2 laser, which gave satisfactory results. (Korean J Dermatol 2007;45(11):1187∼1190)

시열반응과제의 운동학습이 대뇌피질 활성화의 변화에 미치는 영향

권용현 ( Yong-hyun Kwon ),장종성 ( Jong-sung Chang ),김중선 ( Chung-sun Kim ) 대한물리치료학회 2009 대한물리치료학회지 Vol.21 No.1

Purpose: Numerous investigators demonstrated that adaptative changes were induced by motor skill acquisition in the central nervous system. We investigated the changes of neuroelectric potential following motor learning with serial reaction time task in young healthy subjects, using electroencephalography (EEG). Methods: Twelve right-handed normal volunteers were recruited, who have no history of neurological dysfunction and were given to written the informed consent. All subjects were assigned to flex to extend the wrist joint or flex the thumb for pressing the matched button as quickly and accurately as possible, when one of five colored lights was displayed on computer screen (red, yellow, green, blue, white). EEG was measured, whenfive types simulations ware presented randomly with equal probabilities of 20% in total 200 times at the pre and post test. And they were scheduled for 30 minutes practice session during two consecutive days in the laboratory. Results: The results showed that the reaction time at the post test was significantly reduced, compared to one of the pre test in serial reaction time task. In EEG map analysis, the broaden bilateral activation tended to be changed to the focused contralateral activation in the frontoparietal area. Conclusion: These findings showed that acquisition of motor skill led to product more fast motor execution, and that motor learning could change cortical activation pattern, from the broaden bilateral activation to the focused contralateral activation. Thus we concluded that the adaptative change was induced by motor learning in healthy subjects.

편측 뇌손상 환자에서 동측 상지의 근위부 및 원위부의 운동 결함에 관한 분석

권용현 ( Yong Hyun Kwon ),최진호 ( Jin Ho Choi ),신화경 ( Hwa Kyung Shin ),배대석 ( Dai Seg Bai ) 한국전문물리치료학회 2005 한국전문물리치료학회지 Vol.12 No.1

Conditional Clauses and Will

권용현(Yong-Hyun Kwon) 한국외국어대학교 영미연구소 2011 영미연구 Vol.24 No.-

It is well known that the present simple tense is chosen in a conditional clause even if it has a future reference with will in the main clause. The choice of the present simple tense has long been regarded as tense simplification. This article suggests an alternative view to the traditional analysis. This research claims that the choice of the present simple tense is not an omission of will in the clauses, but that the absence of will has its own reason. To deal with the issue properly, we need to distinguish between assumption and prediction. The absence of will in an if clause is to indicate that the protasis of a conditional is an assumption, not a prediction. In the special case of a predictional will in an if clause, such as If the play will be cancelled, let’s not go, it is claimed in this paper that the one conditional is a compressed version of two conditionals. When it is decompressed back, we can see that each protasis of the two conditionals is an assumption.

외교적 갈등이 기업가치에 미치는 영향에 관한 연구

권용현(Yong Hyun Kwon),이지상(Jisang Lee) 한국경영학회 2018 經營學硏究 Vol.47 No.1

This paper addresses empirical evidences on the effects of diplomatic conflicts with neighboring countries on the value of industry and corporations. After the Cold War era, diplomatic conflicts among countries are increasingly being treated as economic sanctions, and Korea-China conflict over THAAD deployment is proceeding similarly. As such, diplomatic conflict can have a significant impact on the stock and financial markets of the country, and is viewed as a potential risk to industries and firms. However, there is no concrete and empirical research on the extent to which these diplomatic conflicts actually have an impact on the value of each industry and firm. One reason is that it is unclear about the specific measures that can be used to verify the link between the countries subject to diplomatic conflict and domestic firms. In this study, we examine the effects of diplomatic conflict on corporate value by using an event study with World Input Output Table, history of company analysis and web scraping. As results, in the case of diplomatic conflict, we find no evidence of positive relationship between the industrial relations and corporate values. However, there is a negative impact on corporate value, whether investing in China through affiliated companies, inherent sensitivity of individual companies, and high exposure to news related to THAAD.

How Compatible Are If and Will?

Yong-hyun Kwon(권용현) 담화·인지언어학회 2004 담화와 인지 Vol.11 No.2

One of the mistaken understandings is that will/would are not allowed in the if-clause. However, this is not true. This paper is to explore what determines the appearance of will/would in if-clauses and other constructions. The distinction between the intrinsic and extrinsic use of will/would needs to be made in order to grasp their functions. This paper is to make three suggestions. The first one is that will/would are free to appear in any type of clauses if they are in intrinsic use. In this case, they act as a full verb just like ordinary verbs. The second one is that will/would can be allowed anywhere when they are in extrinsic use. In this case, they have a role of prediction as a modal verb. The third one is that they are not allowed when the situation is assumed. Whether the situation is a prediction or an assumption plays an important role when we have to decide to use will/would. If speakers assume a situation, they are not allowed either in the matrix or in the subordinate clause. If speakers predict a situation, they are allowed to be in both of the clauses, where they are in extrinsic use. This tells us that the use of will/would has a direct relationship with the attitude of speakers.