open access
메뉴
E-ISSN : 2733-4538
작업 기억의 인지 과정 단계와 신경생리적 기전을 2-back 과제와 사건관련전위를 사용하여 조사하였다. 원, 삼각형 및 정사각형이 자극으로 사용되었으며, 이 중에서 원이 목표 자극이었고, 삼각형과 정사각형이 비목표 자극이었다. 목표 자극인 원은 다시 일치 원과 불일치 원으로 구분되었다. 현재 제시되는 자극이 원이고 2 시행 전에도 원이 제시되었을 경우 (일치 원), 피험자에게 버튼을 눌러 반응하는 것이 요구되었다. 그러나 현재 제시되는 자극이 삼각형 혹은 정사각형이거나 (비목표 자극), 현재 제시되는 자극이 원이더라도 2 시행 전에 원이 제시되지 않았으면 (불일치 원), 피험자의 반응이 요구되지 않았다. 목표 자극(일치 원과 불일치 원)은 비목표 자극에 비하여 유의하게 큰 N100 진폭을 보였다. P300의 경우, 일치 원이 불일치 원과 비목표 자극에 비해 더 큰 진폭과 더 짧은 잠복기를 보였다. 이에 덧붙여, 일치 원은 두정 부위에서 가장 큰 전위를 보인 반면 불일치 원과 비목표 자극은 전두 부위에서 가장 큰 전위를 보였다. 세 유형의 자극 모두 전두 부위에서 유사한 진폭과 잠복기를 가진 서파를 보였다. 이 결과들은 작업 기억에 관여하는 인지 과정의 단계들, 즉 주의 할당, 작업 기억 내용의 최신화 및 추후 시행을 위한 정보의 일시적 보유 등이 사건관련전위의 정점들을 통하여 반영된다는 것을 보여준다. 또한 작업 기억의 신경 회로를 구성하는 전전두엽과 두정엽이 각각 정보의 일시적 보유와 기억 내용의 최신화 과정에 관여한다는 것을 시사한다.
The temporal stages of the cognitive processes and the neurophysiological mechanisms underlying the working memory were investigated using the 2-back task and event-related potential (ERP). Geometric figures such as a circle, triangle and square were used as stimuli. The target stimulus was a circle, while the triangle and square served as nontargets. The target stimulus was further divided into the match target and nonmatch target. If the current stimulus was a circle, and the circle was presented two trials earlier (match circle: MC), the subjects were required to respond. If the current stimulus was a circle, but the circle was either not presented two trials earlier (nonmatch circle: NC), or the current stimulus was either a triangle or a square (nontarget stimulus: NS), subjects were asked not to respond. The target stimulus, i. e., MC and NC produced a significantly higher N100 amplitude than the nontarget stimulus, which indicates that more attention was directed to the target stimulus than to the nontarget stimulus. In terms of P300, the MC than either the NC or NS elicited a greater amplitude and earlier latency. In addition, the P300 was at a maximum at the parietal sites in the MC, while it was at its highest at the frontal sites in the NC or NS. All three types of stimuli produced a positive slow potential with similar amplitudes and latencies. The amplitude of the slow potential was at a maximum at the frontal sites. These results indicate that such temporal stages of cognitive functions underlying the working memory as attention allocation, updating the working memory contents and the retention of sequential information can be reflected toward the ERP components. The results also suggest that the prefrontal and parietal cortex, which are known to be the neural networks of working memory, are associated with the retention process and updating working memory contents, respectively.
(1992) Working memory,
(1986) Working memory, Clarendon press
(1995) Event-related brain potentials differentiate priming and recognition to familiar and unfamiliar faces,
(1999) A topographic event-related potential follow-up study on 'prepulse inhibition' in first and second episode patients with schizophrenia,
(2001) Slow cortical potentials during retention of object, spatial and verbal information,
(1997) A parametric study of prefrontal cortex involvement in human working memory,
(1998) Functional magnetic resonance imaging brain mapping in psychiatry: methodological issues illustrated in a study of working memory in schizophrenia,
(1990) a theoretical account of the processing in the Raven Progressive Matrices Test,
(1988) Is the P300 component a manifestation of context updating,
(1999) Individual differences in working memory capacity and what they tell us about controlled attention, general intelligence and functions of the prefrontal cortex, Cambridge University Press
(1990) The relationship of working memory to the immediate recall of stories following unilateral temporal and frontal lobectomy,
(2000) Gevins, A., and Smith, M. E,
(1996) High resolution evoked potential imaging of the cortical dynamics of human working memory,
(1990195-208) Cross-modal selective attention effects on retinal,
(1983) Electrophysiology of cognitive processing,
(1973) Electrical signs of selective attention in the human brain,
(2000) Working memory dysfunction and its relevance to schizophrenia, Oxford University Press
(2000) Updating of working memory in a running memory task: an event-related potential study,
(1994) Electrophysio- logical correlates of feature analysis during visual search,
(1998) Right anterior prefrontal cortex activation during semantic monitoring and working memory,
(1997) Infrequent events transiently activate human prefrontal and parietal cortex as measured by functional MRI,
(2001) Neurophysiological signals of working memory in normal aging,
(1996) Event-related potentials reveal topographical and temporal distinct neural activation patterns for spatial and object working memory,
(1999) Prefrontal involvement in visual working memory,
(2000) Working memory for letters, shapes and locations: fMRI evidence against stimulus-based regional organization in human prefrontal cortex,
(1996) Evidence for a two-stage model of spatial working memory processing within the lateral frontal cortex: a positron emission tomography study,
(2000) Working memory dysfunction in major depression: an event-related potential study,
(1974) Decision making and the P300 component of the cortical evoked response,
(1988) From neuropsychology to mental structure, Cambridge University Press
(1999) Neurophysiological indices of strategy development and skill acquisition,
(1990) Orbital frontal and amygdala volume reductions in obsessive-compulsive disorder Archives of General Psychiatry,
(1984) New York Academy of Sciences,
(1996) fMRI applications in schizophrenia research,
(19931955-1958) Dissociation of object and spatial processing domains in primate prefrontal cortex,
(19931955-1958) Dissociation of object and spatial processing domains in primate prefrontal cortex,
