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        검색결과 4

        1.
        2018.07 구독 인증기관 무료, 개인회원 유료
        The young generation that was born in the digital age grew up with digital technologies; they listen to music online on web sites like YouTube, which provides access to music by artists from all over the world. We conducted a functional near-infrared spectroscopy (fNIRS) experiment with fifty-six young adults. The human brain generates electrical waves as long as it lives. Since the dynamic nature of brain rhythm is at work in all kinds of human brain function, neuroscientists have used brain rhythm to understand brain function. Since the work of Gerstein and Mandelbrot (1964), many attempts have been made to use random-walk analyses to account for brain responses like the spiking of neurons, cell migration, and motor variability. Like any other biological system, the brain pursues functional efficiency at all levels of operation—in the brain’s case, from the neuronal cell level to the neural network level. Before one can determine the presence of a periodic rhythm versus a random state in brain activation, one must determine whether external stimuli can shape the brain’s modulation pattern. Brain-wave patterns are affected by whether the neural circuit that governs a particular set of brain functions reaches a significant level of activation. The bottom-up processing of external stimuli can be affected by top-down processing; in other words, the execution of higher-order cognitive attention can affect the degree of randomness in the bottom-up processing of external sensory inputs like that of music. Unlike EEG signals, the rhythms of hemodynamic signals are not commonly calculated, possibly because hemodynamic signals are sluggish. The random-walk test on neural time series has been applied only recently to magnetoencephalography (MEG) data (Kipiński, König, Sielużycki, & Kordecki, 2011), and it has rarely been applied to hemodynamic signals measured with magnetic resonance imaging (MRI) or near-infrared spectroscopy (NIRS). However, since hemodynamic responses are the result of neurovascular coupling—a dynamic event among the brain’s neurons, glias, and vasculatures—it is possible to calculate the degree of randomness of hemodynamic signals as surrogates for neuronal activity. While brain activities are inherently random and noisy in their natural state, when the brain rhythm is modified by music that provides appropriate levels of sensory stimulation, the brain’s signals will begin to reflect the music’s rhythms. This reflection is called “attunement.” The effect of sensori-neural stimulation on hemodynamic responses measured by fNIRS has been reported in neuroscience research that found that auditory stimulation and music elevated the concentrations of oxygenated hemoglobin (HbO2) and total hemoglobin (HbT) in blood flow to certain regions of the brain (Hoshi & Tamura, 1993; Kotilahti et al., 2010; Sakatani, Chen, Lichty, Zuo, & Wang, 1999). However, studies have shown decreases (increases) in children’s (adults’) prefrontal cerebral volume after they play computer games. For example, one study suggested that the level of attention may modulate the directional changes in HbO2 and HbT concentrations (Nagamitsu, Nagano, Yamashita, Takashima, & Matsuishi, 2006). The brains of children who find that a game lacks adequate levels of perceptual stimulation do not require an additional supply of oxygen, but adults who find playing the same game a cognitive challenge require more effort to perform the same task, so they require elevated levels of oxygen in their brains (Ferreri et al., 2014). According to musical theorists, when the brain is entrained, the attention follows the music (London, 2012). When members of the digital generation listen to music, the perceptual stimulation level is likely to related to the degree of randomness in brain responses as well as the quality of the sensory experience. Drawing on the literature review, we predict that TBF is higher for a stimulus that is above OSL than the TBF for a counterpart stimulus that is below OSL. We also predict that the hemodynamic rhythm of related brain regions to music that is above OSL adopts a regular predictable pattern. Hence, we propose the following research hypotheses: H1: Digital music that provides acoustic stimulation near the OSL creates brain responses in the form of higher TBF and lower randomness in HbO2 concentrations than does digital music that provides acoustic stimulation that is below the OSL. Functional Near-infrared Spectroscopy The transparency of biological tissue to light in the near-infrared wavelengths makes NIRS possible. NIRS is non-invasive and portable, and it has a cost advantage. The incident near-infrared light from a transmitting optode (source) is scattered through the tissues, and the reflected light is detected by a receiving optode (detector). The amount of the source light that a tissue absorbs depends on the light’s wave length, and the oxygenation status determines the brain’s absorption of the light. The loss of the intensity that is due to the absorption of the photons can be measured in units of optical density (Zaramella et al., 2001). The changes in [oxy-Hb] and [deoxy-Hb] can be calculated according to the modified Beer-Lambert law (Kocsis, Herman, & Eke, 2006) using two wave lengths of near-infrared light—in our case, 780 and 850nm. We used a 12-channel wireless fNIRS system (Biomedical Optics Lab, Korea University) with sampling rates of 8 ~10 Hz to measure the participants’ hemodynamic response while they watched the videos. The system consists of three light sources and five detectors (a 3×7 grid). The fNIRS probe was attached to each subject’s forehead. The detectors of the lowest line were set along the Fp1 and Fp2 electrode line according to the international 10/20 system. Measurements from channels 1, 2, 11, and 12, which contained noise from movements of the subjects’ heads, hair, and sweat, were excluded from further analysis. Neuroscience research has recorded acoustic stimulation in various regions of the brain, including the temporal brains of newborn babies (Hoshi & Tamura, 1993) and the frontal brains of adults (Sakatani et al., 1999). Since infrared light cannot penetrate hair, brain regions that are not covered by hair, such as the prefrontal cortex, are well-suited to an fNIRS study. When a member of the digital generation listens to music online, the motivation is usually enjoyment, so brain activity changes that are due to popular music should occur in brain areas that are associated with reward-related processing—that is, the medial pre-frontal cortex (mPFC) (Haber & Knutson, 2010). As the mental function of pleasurable experience that is modulated in the medial frontal cortex increases, TBF to this region increases. In particular, the processing of sounds is dominantly modulated by the brain’s right hemisphere (Kaiser, Lutzenberger, Preissl, Ackermann, & Birbaumer, 2000). We analyzed TBF to the right brain area of the mPFC at channel 5 using fNIRS. The research hypothesis predicts that songs that provide strong sensory stimulation above the OSL increase the TBFs of those in the digital generation more than do songs that present a sensory stimulation level that is much under the OSL. TBF can be directly obtained as a product of HbT (Wyatt et al., 1990). After the music began in the experiment, the subjects’ concentrations of HbT increased until HbT reached its peak at around five to eight seconds; then it decreased for the next thirty seconds. There was a divide of hemodynamic responses between the two songs that had more than a million hits per day (A and B) and the remaining three (C, D, and E). We conducted repeated measures of ANOVA on TBF, measured at forty seconds, for the five songs, since TBF at the end of each set of song segments can represent the digital generation’s level of sustained attention. The multivariate test for the model was significant, and the main effect of songs on TBF was significant (Wilk’s Lambda 0.75, F(4,51)=4.249, p=0.005,  ). After the forty seconds of each song were over, the TBF levels remained at the highest level for song A, followed in order by Songs B, C, D, and E. Pairwise comparisons after the Bonferroni correction showed that there was a significant divide in the length of time that the TBF levels remained at the highest level between songs A/B and songs C/D/E (p<0.05). Other differences were not significant, possibly because the neural data contained large individual difference variances (between-subject F test: F(1,54) =38.501, .p<0.001, ). The results support hypothesis 1. Next, we examined the relationships between TBF and daily hits, and BORP and daily hits. The Pearson correlation coefficient between TBF and daily hits was 0.88 (p<0.05), and the correlation coefficient between BORP and daily hits was -0.96 (p<0.05). Pairwise comparisons after the Bonferroni correction showed that, there was a significant divide in the length of time that the TBF levels remained at the highest level between songs A/B and songs D/E (p<0.05). Other differences were not significant, possibly because neural data contains a large portion of individual variance (between-subject F test: F(1,54) =372.675, p<0.001,  ). These results are consistent with our hypothesis 1b that pop music that presents stimulation above OSL can reduce the randomness in hemodynamic signals. The changes in the participants’ hemoglobin concentrations while they listened to popular songs show a mean-reverting tendency with low BORP—a “rhythm” such that a system recovers order and balance in due time. The brain’s response to less popular songs were random-walk processes, which represents a neural drain, a process in which brain fails to recover from oxygen depletion because of boredom. In conclusion, we found that total blood flow to the right medial prefrontal cortex increased less when the young adults were exposed to music that presented acoustic stimulation near the optimal sensory load (OSL) than it did when they were exposed to songs with a level of stimulation much below the OSL. The degrees of hemodynamic randomness decreased significantly while the participants listened to online music that provided near-OSL stimulation. Online popularity, recorded as the number of daily hits, was significantly positively correlated with the total blood flow and negatively correlated with hemodynamic randomness. These findings suggest that a new digital media strategy may be required that provides a sufficient level of sensory stimulation as an essential part of marketing to the digital consumer generation.
        3,000원
        2.
        2021.10 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 기능적 근적외선 분광법인 fNIRS(functional Near-Infrared Spectroscopy)를 활용하여 미술표현에 따른 뇌 활성화를 측정하는 것이다. fNIRS는 소형의 크기에, 휴대성이 용이하고, 근적외선이 연구참여자의 전두엽에 비침습적으로 침투하여 대뇌의 혈류량을 파악하고, 이를 토대로 뇌의 활성화 상태를 측정하는 장비이다. K대학 소재의 연구참여자 4명을 대상으로 fNIRS 를 착용 후 1분 30초씩, 총 3번에 걸쳐서 미술표현 활동을 진행하였고, 개별 뇌 활성 이미지와 4명 의 평균 뇌 활성 이미지 및 그래프를 추출하였다. 분석결과 연구참여자 4명의 모든 미술표현 활동에서 시각적 작업기억을 담당하는 우측의 DLPFC영역, 메타인지와 평가 및 성찰을 담당하는 FPC 영역, 그리고 가치 부여 및 판단을 담당하는 OFC영역이 활성화 되었음을 확인하였다. 분석결과를 토대로 미술교육의 시사점 및 나아가야 할 방향을 제안하였다. 첫째, 미술활동은 우뇌와 좌뇌의 활성이 함께 일어나지만 비교적 우뇌가 더 많이 활성화 된다. 둘째, 미술표현활동은 주의집중과 목표지향적 행동, 동기부여를 유발하는 교과이다. 셋째, 미술표현 활동에서 자기평가와 성찰을 위해 표현 후 결과물에 대해 발표 및 소감문을 작성해 보는 시간이 필요하다. 넷째, 미술할동에서 주제를 제시할 때 막연하고 추상적인 주제가 아니라 구체적인 언어와 단어로써 제시해야 한다. 본 연구를 토대로 앞으로 미술교과와 관련된 과학적이고 객관적, 실증적인 연구가 많이 진행되어 미술교과의 위상을 높이고, 더 좋은 후속연구들이 이루어지기를 기대한다.
        3.
        2021.09 KCI 등재 서비스 종료(열람 제한)
        목적: 본 연구는 안구운동 민감소실 재처리 기법(EMDR)이 운동선수의 경쟁상태불안에 미치는 영향을 알아보기 위해 fNIRS를 활용해 전전두엽 피질의 활성화 차이를 비교해 효과를 검증하는 것이다. 방법: 이 연구의 목적을 달성하기 위해 불안요소면담, 경쟁상태불안검사지(CSAI-2), 스포츠심상능력질문지(SIAQ)를 활용하여 대학부 운동 선수 9명을 선정하였으며, 실험을 위해 OBELAB fNIRS장비와 Matlab 소프트웨어를 사용하여 분석하였다. 연구는 시간 순서대로 전전두엽의 활성화를 측정하였으며, 기저선, 사전심상, 양측성안구운동프로그램, 사후심상 순으로 진행하였다. 결과: 첫째, 경쟁불안을 유발하기 위해 심상을 활용한 결과, 전반적인 전전두엽의 활성화가 낮아졌다. 둘째, 양측성 안구운동 프로그램 적용 결과, 사전심상과 사후심상에서 우측 전전두엽의 활성이 낮아졌다. 셋째, 양측성 안구운동 회기별 측정 결과, 양측성 안구운동 중 우측 전전두엽이 활성화되었다. 결론: EMDR이 운동선수의 경쟁불안과 관련된 기억으로 인한 부정적인 정서상태를 긍정적으로 빠르게 재처리 할 수 있다는 것을 보여준다. 본 연구는 스포츠라는 특수한 상황에서 발생하는 예기치 못한 경쟁불안을 빠르게 조절하는 데에 EMDR을 적용할 수 있는 가능성을 제시한다.
        4.
        2020.08 KCI 등재 서비스 종료(열람 제한)
        목적: 본 연구는 시-공간적인 작업기억 과제 수행 시 국가대표, 선수, 비선수의 행동학적 특성과 전전두엽의 뇌 연결성을 파악하여 우수한 경기력을 지닌 선수가 가지는 작업기억 능력의 차이를 규명하는 것이 목적이다. 방법: 이를 위하여 라켓종목 선수 국가대표 선수 12명, 선수 12명, 비선수 12명씩 총 36명이 연구에 참여하였다. 실험 과제는 시-공간적 N-back 과제를 난이도에 따라 1-back, 2-back으로 나눠서 60회씩 3회기 총 180회씩 총 360회를 수행하였고, 차이를 규명하기 위해 근적외선분광분석기(fNIRS)와 반응키를 활용하여 전전두엽의 연결성과 반응시 간을 측정하였다. 결과: 과제 수행에서 국가대표가 다른 두 집단보다 반응시간에서 통계적으로 유의한 차이가 나타났으며, 전전두엽의 연결성에서도 국가대표 집단이 강한 연결성을 나타냈다. 결론: 세계적인 경기력 수준을 가진 국가대표 선수들은 경기와 관련된 인지적 요소뿐만 아니라 일반적인 작업기억 능력 또한 우수하다고 판단할 수 있다.