경두개 직류 전류 자극이 시지각 과제의 수행 능력에 미치는 영향 = The Effects of Transcranial Direct Current Stimulation in Motor Performance of Visuomotor Task

다국어 초록 (Multilingual Abstract)

As a non-invasive technique for brain stimulation, transcranial direct current stimulation (tDCS) modulates the brain activity. Recent studies reported that tDCS enhances motor learning and working memory. Therefore, this study examined the effect of tDCS on the primary motor cortex of the non-dominant hemisphere in motor performance.
Twenty-two healthy subjects were enrolled in this study. They were divided randomly into two groups, such as the experimental group or sham-controlled group. In the experimental group, tDCS (1 ㎃, 20 mins) was applied to the primary motor cortex and sham-control group was applied for 30seconds only. In addition, a serial reaction time task was carried out before and after tDCS in both groups.
There was enhanced motor performance in both groups due to the repetitive motor execution. However, the experimental group showed larger changes in their reaction time.
Overall, tDCS of the primary motor cortex is effective in stimulating the motor performance in healthy subjects. The results suggest that tDCS may enhance the beneficial effects of neurorehabilitative treatments in stroke patients.

국문 초록 (Abstract)

경두개 직류 전류 자극법은 영구적 이식이나 침습적인 방법이 아닌 비침습적으로 뇌를 자극하는 방법으로써 뇌의 활성화를 조절하여 학습능률 향상을 도모하는 뇌기능 치료법이다. 경두개 직류 전류 자극법이 뇌기능장애환자나 신경계 손상환자의 뇌기능 활성화에 대한 치료적 프로토콜로 제안되는 이유는 시지각과제에 대한 운동학습과 작동 기억 향상에 있으나 아직 시지각과제의 운동수행력 향상을 뒷받침하는 논문은 많지 않다. 그러므로, 본 연구는 비우성 뇌반구의 일차운동영역에 경두개 직류 전류로 자극을 가하여 시지각과제의 운동 수행력에 미치는 영향을 정량적으로 알아보기 위하여 수행되었다. 22명의 정상 성인을 대상으로 무작위로 실험군과 허위-대조군으로 나누었으며, 실험군에서는 비우세 뇌반구의 일차운동영역에 경두개 직류 전류 자극을 1㎃으로 20분 동안 적용하였고, 허위-대조군은 같은 부위에 30초동안 자극하고 대상자들이 모르도록 장치의 전원을 끈 상태로 유지하였다. 연속반응시간과제는 자극 전과 후에 두 그룹 모두에게 반응 시간의 변화를 확인하기 위해 적용되었다.
본 연구의 결과, 자극 전·후 반응시간에는 통계적으로 유의한 차이가 있었으나(p< .05), 집단간과 상호작용에는 통계적으로 유의하지 않았다(p> .05). 반복적인 운동 수행 효과로 인해 두 집단 모두에서 수행력이 향상되었으나, 경두개 직류 전류 자극을 적용한 실험군에서 좀 더 많은 반응시간의 변화가 보였다. 그러므로, 경두개 직류 전류 자극을 적용한 집단이 허위-대조군보다 반응시간에서 좀 더 많은 변화가 있었음을 알 수 있었다. 앞으로의 연구에서 적절한 과제를 통해 효과성이 검증이 된다면 뇌졸중을 가진
환자의 뇌 활성화를 조절하는 신경재활치료에 중재법으로 유용할 것이라 생각된다.

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