Progress in Medical Physics (한국의학물리학회지:의학물리)

Korean Society of Medical Physics (한국의학물리학회)
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The Neural Alteration according to Cognitive Load on Working Memory by Organic-Solvent Exposures

유기용제에 노출된 직업군에서 보여진 작업 기억에서의 인지부하에 따른 신경학적 변화

  • Kim, Tae Geun (Department of Medical & Biological Engineering, Kyungpook National University) ;
  • Seo, Jeehye (Department of Medical & Biological Engineering, Kyungpook National University) ;
  • Kim, Yangho (Department of Occupational and Environmental Medicine, University of Ulsan College of Medicine) ;
  • Yun, Byoung-Ju (School of Electronics Engineering, College of IT Engineering) ;
  • Chang, Yongmin (Department of Medical & Biological Engineering, Kyungpook National University)
  • 김태근 (경북대학교 의용생체공학과) ;
  • 서지혜 (경북대학교 의용생체공학과) ;
  • 김양호 (울산대학교 의과대학 직업환경의학과) ;
  • 윤병주 (경북대학교 IT대학 전자공학부) ;
  • 장용민 (경북대학교 의용생체공학과)
  • Received : 2015.05.09
  • Accepted : 2015.06.19
  • Published : 2015.06.30
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Abstract

Organic solvents are known toxic effects like vertigo, behavioral obstacle, distracting, and peripheral neuropathy in neuron areas. However, there have been few studies how neurotoxic solvents-exposed workers are affected by the cognitive load of preceding working memory tasks. Therefore, we used fMRI as to measure the neural correlates of working memory impairment in occupational workers who had from chronic exposure to organic solvent. Twenty-nine solvent-exposed workers were included in this study. Each participant concluded the verbal N-back tasks (1- and 2-back) during the fMRI acquisition. Within-group analyses showed fronto-parietal networks were active in each condition. Direct comparisons between 1- and 2-back showed higher activation during the 2-back than 1-back. We found that increased activation of these regions at lower task demand is associated with increased cost of implementing.

유기용제는 현기증, 행동장애, 주의산만, 말초신경증과 같은 신경 독성을 일으키는 물질로 잘 알려져 있다. 그러나, 이러한 신경 독성물질인 유기 용제에 노출된 근로자들이 작업 기억 기능을 수행할 때 인지 부하에 어떻게 영향을 받는지에 관해서 많이 연구가 되어오지 않았다. 따라서, 본 연구에서는 기능적인 자기공명영상을 이용하여 만성적으로 유기용제에 노출된 근로자들이 인지 부하에 따른 작업 기억 기능을 수행할 때 보여지는 신경 변화의 관계를 살펴보았다. 29명의 유기용제에 노출된 근로자들을 대상으로 언어적 작업 기억 기능(1-back and 2-back)을 수행시켰으며 낮은 인지 부하와 높은 인지 부하의 작업 기억 기능을 수행할 때, 인지 부하의 차이에 따라 활성화 되는 뇌 영역의 차이를 구하였다. 1-back의 반응속도가 증가함에 따라 좌측 하위 두정 피질에서의 뇌 활성화가 점점 증가하는 관계를 보였는데, 이러한 증가되는 양상이 더 높은 인지 부하인 2-back에서는 보여지지 않았다. 이를 통해, 인지 부하가 많이 걸릴수록 활성화 되는 뇌 영역이 많아지며, 유기용제에 노출된 근로자들은 어느 정도 낮은 인지 부하가 걸렸을 때는 그만큼의 뇌 활성화가 증가되는데, 높은 인지 부하가 걸리게 되면 더 이상 뇌 활성화가 증가되지 않고 한계에 다다르는 것을 알 수 있었다.

Keywords

References

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