이 작품은 미국 육군 연구 사무실 (W911NF-07-1-0415 (GS), W911NF-08-1-0216 (GS))과 NIH / NIBIB (EB006356 (GS)와 EB00856 (가 지원하는 보조금에 의해 가능하게되었다 JRW와 GS)). 저자 SigfriedSigProcLAVA 모듈에 대해 숀 오스틴 감사 및 관련 기술 지원 그리핀 Milsap.

1. 전극 현지화 <ol><li> 슬라이스 당 256 X 256 픽셀,보기의 전체 분야, 아니 보간, 1 밀리미터 슬라이스 폭 선호 화살 크로스 - 섹션 : 환자의 머리 사전 수술 T1-가중 구조적 MRI로 (1.5T 또는 3T)를 수집합니다. </li><li> 격자 및 스트립의 외과 이식을 관찰. 이식 격자 및 스트립의 위치에 디지털 현장에서의 전극의 사진, 그리고 신경 외과 의사의 노트를 수집합니다. </li><li> 고해상도의 수술 두개골 X 선 이미지 및 뇌 중부 표준시 스캔 (1 밀리미터 슬라이스 폭, 피부에 피부, 아니 각도)를 수집합니다. </li><li> 포스트 그리드 주입 중부 표준시 이미지로 미리 수술 MRI 및 공동 등록을 사용하여 환자의 두뇌의 3 차원 피질 모델을 만듭니다. 우리는이 목적을 위해 카레 소프트웨어 패키지를 사용하고, 3D 피질 구조를 내보내고 전극은 MATLAB 형식으로 조정합니다. MATLAB에서, 우리는 두뇌에 매핑 전극을 보여주는 동영상을 내보낼 수 있습니다. 우리는 또한 거든AP는 전극은 자동 Talairach 아틀라스를 사용하여 표준 Brodmann 영역을 조정합니다. </li><li> 3D 모델, X-레이 이미지, 사진과 노트의 정보를 검토합니다. 전극, 그리고 병원은 기술과 함께 작동 전극이 정확히 번호에 따라 스플리터 상자에 패치되는 것을 보장하기위한 번호 체계를 마무리합니다. 또한 전극의 위치를​​ 명확하게 중복없이 구분할 수 있도록 2 차원에서 전극을하려위한 도식 레이아웃을 만듭니다. 당신이 출마 (4 항 참조) SIGFRIED 될 경우, ElectrodeLocations 매개 변수에 필요한 형식으로, BCI2000 파라미터 조각으로 이러한 2 차원 좌표를 저장합니다. 마지막으로, electrocorticographically 될 가능성이 두 전극 위치 선택 &quot;침묵&quot;을 즉, 그들은 (패치 파란색 소켓에 대한 참조에 의해 g.USBamps를 준비, 초기 지상 및 참조로 사용하기 위해 추정된 웅변 피질 근처 없습니다 및 접지각 단위의 극단적인 오른쪽에있는 노란색 소켓,)로 변경합니다. </li></ol> 2. 하드웨어 및 소프트웨어 설치 <ol><li> 컴퓨터 사양이 실험의 처리 요구 사항 처리에 적합한지 확인합니다. 멀티 코어 프로세서는 가능성이 실시간 데이터 수집 및 처리, 비디오 녹화, 기타 필요한 작업의 요구를 수용하기 위해 필요합니다. 1,200 Hz에서에서 128 채널의 녹화 및 실시간 분석을 위해서는 RAM을 4GB의와 함께 3 GHz의 쿼드 코어 시스템을 사용합니다. 앰프는 그러한 외부 드라이브 및 카메라 (이것은 시스템의 장치 관리자를 통해 확인할 수있다)와 같은 다른 대역폭 굶주린 주변 기기에서 사용하는 컨트롤러 (들)와는 전용 USB 컨트롤러에 연결되어 있어야합니다. 마지막으로, 충분한 디스크 실험 데이터의 초당 5메가바이트를 저장할 수있는 공간 및 아카이빙 및 백업을위한 제도가 있어야합니다. </li><li> 연구 장비 (앰프, 컴퓨터, 실험자의 화면, keybo를 설정신속 벽에 연결하는 유일한 단일 전원 코드와 함께 환자의 방에서 나갔다가 다시 굴려 수있는 단일 트롤리, 대한 ARD, 스피커, 마이크 및 카메라). 방에서 방으로 컴퓨터를 이동하려면 뽑기 전에 최대 절전 기능을 사용하십시오. 환자의 비디오 화면은 별도의 트레이 테이블 또는 모니터 암에 있어야합니다. 환자가 발작하는 경향임을 고려하면, 의료진은 환자에 대한 즉각적인 액세스해야하는 경우 모든 장비가 신속하게 비켜 굴려 수 있는지 확인합니다. 장비는 환자의 방에 사용 전후 소독제 잎사귀와 함께 소독하여야한다. </li><li> 환자와 시간 제한, 모든 절차가 건장하고 그 시간을 최대한 활용하도록 최적화되어 있어야합니다. 이와 관련, BCI2000의 유연성과 견고는 귀중한 특성입니다. 실험 버튼을 누르면 실행시킬 수 있는지 확인하십시오. BCI2000의 경우 오른쪽의 조합을 실행하기 위해 배치 파일을 사용하여필요한 명령줄 옵션과 자동 BCI2000 모듈. 교환 및 gUSBampSource 모듈은 특정 실험에 대한 적절한 SignalProcessing 및 응용 모듈과 함께 필요합니다. 모든 필수 매개 변수 파일 등의 전극과 그들의 이름과 위치의 수를 본 환자를 구체적으로 어떤, 자동 포함하여로드되는 것을 보장하기 위해 BCI2000의 운영자 스크립팅 기능을 사용합니다. 이러한 자동화의 목적은 실험자에 의해 수동 단계의 수를, 따라서 오류 기회를 최소화하는 것입니다. 소프트웨어 및 해당 매개 변수가 최소한 하나 또는 이주 주입하기 전에 (아마 뇌파 제목) 종결되고 테스트한해야합니다. 또한 &quot;건조&quot;가 모든 새로운 환자 특정 매개 변수를 포함하여, 첫 번째 실험 세션 전날를 실행 수행할 수 매우 좋습니다. </li></ol> 3. 실험 세션 설정 <ol><li> 귀하의 순간을 선택하세요, 환자에게 실험적인 레코딩을 제안들이 일찍 눈치주고, 그리고 다시 시작 15 분 전에. 주변 방문자, 식사, 낮잠, 의료 절차 및 환자의 신체적, 정서적 및인지 상태를 작동합니다. 그것은 레코딩의 타이밍과 시간을 최적화에 도움, 바닥에 의료 인력과 교감을 확립하는 것이 중요합니다. </li><li> 장소로 휠 장비, 전원 콘센트에 연결, 주제의 비디오 화면을 켜고 컴퓨터에 연결하고 컴퓨터를 취소 겨울잠. </li><li> BCI2000을 시작합니다. VisualizeSource 매개 변수가 활성을 통해 구성 설정을 누르십시오. 신호 뷰어는 ECoG 신호 품질을 평가셔서, 열립니다. 뷰어에서 마우스 오른쪽 단추로 클릭하고 5 Hz에서의 컷오프에 하이 패스 필터를 설정합니다. (이 필터 설정은 시각에 영향을, 그리고 데이터의 수집되지 않습니다.) </li><li> 전력선 잡음의 간섭 확인 : (50 Hz에서 60 Hz에서에서, 보는 사람에 노치 필터를 활성화합니까자네가 어떤 국가에 따라 다름) 신호에 큰 차이를 만든다고? 그렇다면, 사용하지 않은 크로스 얘기 케이블을 제거하거나 전원 간섭의 다른 소스를 식별하고 제거하여이 작업을 줄이기 위해 시도합니다. 참조 및 지상 필요한 경우에 사용되는 전극을 변경합니다. </li><li> 당신이 눈을 추적기를 사용하는 경우 제조 업체에서 제공한 보정 소프트웨어를 사용하여 그것을 보정. BCI2000 소스 모듈이 포함되어 EyetrackerLogger 확장자로 컴파일해야하고, 함께 시작되어야합니다 - LogEyetracker = 1 플래그가 안구 추적 데이터 ECoG 신호와 동기화 인수받을 수 있도록 활성화. </li><li> 산만하고 중단을 방지하려면 가능한 신호 간섭을 최소화하기 위해, 텔레비전, 라디오, 휴대폰 전원이 꺼져 있는지 확인합니다. </li><li> 당신이 실행하려고 실험을 위해 환자에게 정확한 지침을 줘. 작업을 보여주 파워 포인트 슬라이드를 준비, 주제의 과제에 따라 제안하는 자세 등이 유용합니다. </lI&gt; <li> 실험을 시작하려면 연산자에서 시작을 누릅니다. 당신 누르면 때마다 시작하거나 재개, 새 파일은 이전 데이터를 덮어 쓰지 않도록 만들어되며, 파일은 모든 매개 변수 값의 사본과 함께 초기화됩니다. 당신이 중지 또는 실험 실행 완료를 누를 때까지 원시 데이터는 다음 이벤트 마커와 함께 파일에 자동으로 스트리밍됩니다. </li><li> 세션 동안 환자의 행동과 의심되는 발작에 대한 ECoG 신호를 모니터링, 의료 직원의 지시에 응답할 준비. </li></ol> 4. 예 실험 세션 : BCI2000와 SIGFRIED 임상 매핑 <ol><li> 준비 : 세션이 시작하기 전에 SIGFRIED이 모델을 구축하는 데 사용할 신호 처리 설정이 들어 model.ini 파일을 준비하셔야하며, PRM 파일 (또는 별도의 PRM의 파편.) 그 BCI2000 매개 변수를 포함하는. SigfriedSigProc 모듈실시간 시각화를 위해 사용합니다. 두 개의 주요 매개 변수는 서로 다른 태스크가 어떤 조건 하에서 매핑되는 지정이 환자의 특정 전극, 그리고 ElectrodeCondition을 위해 선택한 2-D 레이아웃을 지정 ElectrodeLocations 있습니다. 이 예제에서, 우리는 환자에게 지시를 통신하기위한 간단한 StimulusPresentation 모듈을 사용하고 있으므로 자극 매개 변수는 또한 우리가 실행하려는 작업에 적응해야합니다. </li><li> 기준 단계 : 1200Hz의 모든 격자 및 스트립에서 샘플 ECoG 활동으로 구성된 gUSBampSource, DummySignalProcessing 및 StimulusPresentationTask 모듈을 시작, 0.1 Hz에서에서 하이 패스 - 여과. 휴식과 열린 눈으로 움직이지 남아 주제를 지시한다. 조용한 환경에서 편안한 조명 아래에서 기본적인 활동의 기록은 6 분. </li><li> 모델링 단계 : data2model_gui 도구를 시작합니다 5 Hz에서 제품 용기 천을에서 특징을 추출데이터의 모든 500 MS에 대해 최대 엔트로피 방법을 사용 톰 70-110 Hz에서. 가우스 섞어 사용하여 선택된 스펙트럼 기능의 확률적 모델을 구축하기위한 모델을 구축 누르십시오. </li><li> 매핑 단계 : gUSBampSource, SigfriedSigProcLAVA 및 StimulusPresentationTask 모듈을 시작하고 확률적 모델을로드하려는 연산자, 대뇌 피질 모델, 2 개의 구성 - 3 차원 전극 좌표. 제목을 지시하면 매핑 프로세스를 시작합니다. 이 과정에서 주제는 5 번 반복 각각에 한 번에 10 초 동안 각 작업을 수행합니다. 그리고 설득력 피질의 3 차원지도 - 각 작업 중에 SIGFRIED은 작업 관련 ECoG에 지속적으로 업데이 트 2에 제시되어 활동을 감지합니다. 2 차원지도에서 각 원의 크기와 빨갛게이 특정 작업에서의 중요성을 나타냅니다. 특히, 각 원의 크기는 감마 바의 총 신호 분산의 분율에 비례작업에 의해 집결되는 차. 이 통계는 결정 계수, 또는 R 2로 알려져있다. 그것은 범위 (0,1)에 있으며 현재 설정에 0.1의 가치는 일반적으로 중요한 것으로 간주됩니다. 최대 R 2 값을 동그라미의 크기 조절은 슬라이더를 (그림 1C 참조)를 사용하여 제어할 수 있습니다. 3 차원지도에서 R 2 값은 오히려 원형 크기와는 다른 색상으로 매핑됩니다. </li></ol> 5. 대표 결과 그림 1은 한 환자에서 한 SIGFRIED 매핑 세션에서 대표적인 결과를 보여줍니다. 환자는 이차 일반화와 왼쪽 측두엽 증상도 아냐 현지화 관련 간질을 가진 28 세의 오른손잡이 여자였다. 120 electrocorticographic 전극은 왼쪽 전두엽, 두정 골과 측두엽 피질을 통해 subdurally 심어했다. 측면 X 선 (패널)과 내부 첩자 사진 (패널 B)가 묘사40 전극, 68 전극과 하나가 더 높은 밀도의 시간적 그리드, 세 스트립 4 전극 각각 한 정면 격자의 구성. 기록 발작에서 신경과 간질 foci를 현지하고 설득력 언어 피질을 살려주는 반면 왼쪽 측두엽 외과 절제술을 수행하기 위해 필요하다고 판단. 이것은 성공적으로 수행 되었음 : 8개월 포스트 절제술에서 환자는 발작이 무료로 및 신경학적인 결손없이 평가되었습니다. 수동 매핑 절차는 듣기 작업하는 동안 작업 관련 변경 사항을 대조하여 언어 기능에 관여 확인된 피질을 SIGFRIED. 전극의 레이아웃은 분명하게 2 차원 인터페이스 (패널 C), 그리고 3 차원 해부학적인 몸의 구조 - 올바른 인터페이스 (패널 D) : 결과는 두 개의 인터페이스로 표시되었습니다. 왼쪽부터 색조 대 기준 (색조)으로 듣기, 구어 대 기준 (음성)으로 듣기와 구어 VS LIS를 듣고 바로 판넬 대비로색조 (언어)로 tening. 이 중 마지막은 수용 언어에 특정한 청각 기능의 대략적인 그림으로 포함되어 있습니다. 음성 상태의 결과는 (패널에 노란색 동그라미로 표시)이 환자의 수용 언어 기능을 내장 컴퓨터 시스템 중단되는 위치와 좋은 계약을 보여주었다. <img alt="그림 1" src="/files/ftp_upload/3993/3993fig1.jpg" /> 그림 1. 한명 환자에서 예제 결과입니다. 패널은 가로 X 선을 보여줍니다. 노란색 동그라미는 이후 electrocortical 자극 매핑으로 식별 수용 언어에 연루 전극을 표시합니다. 패널 B는 주입하는 동안 찍은 사진입니다. 패널 C는 배선 2 차원 레이아웃에서 SIGFRIED 매핑 결과를 보여줍니다 : 각 디스크의 크기와 빨갛게은 기준선에 상대적인 작업에서 각 전극의 참여의 중요성을 나타냅니다. 패널 D에서 동일한 통계는 입체적인 두뇌 모델 rende에 색상에 매핑됩니다환자의 MRI에서 빨간색.

<ol>
	<li>Miller, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+Changes+in+Cortical+Surface+Potentials+during+Motor+Movement.">Spectral Changes in Cortical Surface Potentials during Motor Movement.</a> Journal of Neuroscience. 27, 2424-2424 (2007).</li><li>Chang, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Categorical+speech+representation+in+human+superior+temporal+gyrus.">Categorical speech representation in human superior temporal gyrus.</a> Nature Neuroscience. 13, 1428-1428 (2010).</li><li>Gunduz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+correlates+of+visual-spatial+attention+in+electrocorticographic+signals+in+humans.">Neural correlates of visual-spatial attention in electrocorticographic signals in humans.</a> Frontiers in Human Neuroscience. 5, (2011).</li><li>Pei, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatiotemporal+dynamics+of+electrocorticographic+high+gamma+activity+during+overt+and+covert+word+repetition.">Spatiotemporal dynamics of electrocorticographic high gamma activity during overt and covert word repetition.</a> NeuroImage. 54, 2960 (2010).</li><li>Crone, N. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-frequency+gamma+oscillations+and+human+brain+mapping+with+electrocorticography.">High-frequency gamma oscillations and human brain mapping with electrocorticography.</a> Progress in Brain Research. 159, 275 (2006).</li><li>Brunner, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+communication+with+a+"P300"+matrix+speller+using+electrocorticographic+signals+(ECoG).">Rapid communication with a "P300" matrix speller using electrocorticographic signals (ECoG).</a> Frontiers in Neuroprosthetics. 5, (2010).</li><li>Leuthardt, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+brain-computer+interface+using+electrocorticographic+signals+in+humans.">A brain-computer interface using electrocorticographic signals in humans.</a> Journal of Neural Engineering. 1, (2004).</li><li>Schalk, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BCI2000:+A+General-Purpose+Brain-Computer+Interface+(BCI)+System.">BCI2000: A General-Purpose Brain-Computer Interface (BCI) System.</a> IEEE Transactions in Biomedical Engineering. 51, 1034 (2004).</li><li>Schalk, G., Mellinger, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> A Practical Guide to Brain-Computer Interfacing with BCI2000. , (2010).</li><li>Brunner, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+procedure+for+real-time+functional+mapping+of+eloquent+cortex+using+electrocorticographic+signals+in+humans.">A practical procedure for real-time functional mapping of eloquent cortex using electrocorticographic signals in humans.</a> Epilepsy and Behavior. 15, 278 (2009).</li></ol>

관심의 어떠한 충돌 선언 없습니다.

연구 ECoG 데이터를 수집하는 것은 매우 멀티 - 징계 팀 임상 신경학, 신경 외과, 기초 신경 과학, 컴퓨터 과학 및 전기 공학 문제 해결과 함께, 임상의와 연구자 간의 긴밀한 협력이 필요합니다. 보상 ECoG 신호와 높은 감마 주파수 범위 (70-110Hz)에서 특정 amplitudes에서 매우 가치가있다는 것입니다. 그들은 감각,인지의 신경 상호로 과학적인 통찰력을 제공하고 모터는 높은 공간과 시간적 해상도 모두?...

<ol><li> 8 X 16 채널 g.USBamp 증폭기 ( <a href="http://gtec.at" target="_blank">http://gtec.at</a> ) </li><li> 2 X 64 채널 브레이크 아웃 박스 (스플리터 헤드 상자) </li><li> 스플리터의 임상 시스템 2 X 연결 케이블 </li><li> 스플리터 넷이 g.USBamps ~ 2 X 연결 케이블 </li><li> 네 g.USBamps 2 X 4 웨이 전원 어댑터 </li><li> 네 g.USBamps를 동기화하기 위해 2 X 4 - 웨이 동기화 어댑터 </li><li> 1 X 동기화 케이블 네 가지 g.USBamps 두 세트를 동기화하는 방법 </li><li> 1 X 잠재-균등화 클램프 + 케이블 g.USBamp 용 </li><li> 18 X Touchproof 점퍼 케이블 </li><li> 2 X 4 웨이 USB 2.0 허브 </li><li> 파워 스트립 </li><li> 노트북 또는 데스크탑 컴퓨터 (섹션 2.1 참조) </li><li> 위의 모든 보안, 움직일 수있는 카트 </li><li> 환자를위한 Eyetracker (또는 일반 LCD 모니터) </li><li> 환자 모니터 움직일 수있는 트레이 테이블 </li><li> 환자의 행동 반응에 대한 기타 주변 기기 (조이스틱 등) </li><li> BCI2000 소프트웨어 </li><li> CURRY 소프트웨어 </li><li> MATLAB 소프트웨어 </li></ol>

recording human electrocorticographic (ecog) signals for neuroscientific research and real-time functional cortical mapping

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), magnetoencephalography or functional magnetic-resonance imaging. These techniques have either inherently low temporal or low spatial resolution, and suffer from low signal-to-noise ratio and/or poor high-frequency sensitivity. Thus, they are suboptimal for exploring the short-lived spatio-temporal dynamics of many of the underlying brain processes. In contrast, the invasive technique of electrocorticography (ECoG) provides brain signals that have an exceptionally high signal-to-noise ratio, less susceptibility to artifacts than EEG, and a high spatial and temporal resolution (i.e., &lt;1 cm/&lt;1 millisecond, respectively). ECoG involves measurement of electrical brain signals using electrodes that are implanted subdurally on the surface of the brain. Recent studies have shown that ECoG amplitudes in certain frequency bands carry substantial information about task-related activity, such as motor execution and planning1, auditory processing2 and visual-spatial attention3. Most of this information is captured in the high gamma range (around 70-110 Hz). Thus, gamma activity has been proposed as a robust and general indicator of local cortical function1-5. ECoG can also reveal functional connectivity and resolve finer task-related spatial-temporal dynamics, thereby advancing our understanding of large-scale cortical processes. It has especially proven useful for advancing brain-computer interfacing (BCI) technology for decoding a user's intentions to enhance or improve communication6 and control7. Nevertheless, human ECoG data are often hard to obtain because of the risks and limitations of the invasive procedures involved, and the need to record within the constraints of clinical settings. Still, clinical monitoring to localize epileptic foci offers a unique and valuable opportunity to collect human ECoG data. We describe our methods for collecting recording ECoG, and demonstrate how to use these signals for important real-time applications such as clinical mapping and brain-computer interfacing. Our example uses the BCI2000 software platform8,9 and the SIGFRIED10 method, an application for real-time mapping of brain functions. This procedure yields information that clinicians can subsequently use to guide the complex and laborious process of functional mapping by electrical stimulation.
Prerequisites and Planning:
Patients with drug-resistant partial epilepsy may be candidates for resective surgery of an epileptic focus to minimize the frequency of seizures. Prior to resection, the patients undergo monitoring using subdural electrodes for two purposes: first, to localize the epileptic focus, and second, to identify nearby critical brain areas (i.e., eloquent cortex) where resection could result in long-term functional deficits. To implant electrodes, a craniotomy is performed to open the skull. Then, electrode grids and/or strips are placed on the cortex, usually beneath the dura. A typical grid has a set of 8 x 8 platinum-iridium electrodes of 4 mm diameter (2.3 mm exposed surface) embedded in silicon with an inter-electrode distance of 1cm. A strip typically contains 4 or 6 such electrodes in a single line. The locations for these grids/strips are planned by a team of neurologists and neurosurgeons, and are based on previous EEG monitoring, on a structural MRI of the patient's brain, and on relevant factors of the patient's history. Continuous recording over a period of 5-12 days serves to localize epileptic foci, and electrical stimulation via the implanted electrodes allows clinicians to map eloquent cortex. At the end of the monitoring period, explantation of the electrodes and therapeutic resection are performed together in one procedure.
In addition to its primary clinical purpose, invasive monitoring also provides a unique opportunity to acquire human ECoG data for neuroscientific research. The decision to include a prospective patient in the research is based on the planned location of their electrodes, on the patient's performance scores on neuropsychological assessments, and on their informed consent, which is predicated on their understanding that participation in research is optional and is not related to their treatment. As with all research involving human subjects, the research protocol must be approved by the hospital's institutional review board. The decision to perform individual experimental tasks is made day-by-day, and is contingent on the patient's endurance and willingness to participate. Some or all of the experiments may be prevented by problems with the clinical state of the patient, such as post-operative facial swelling, temporary aphasia, frequent seizures, post-ictal fatigue and confusion, and more general pain or discomfort.
At the Epilepsy Monitoring Unit at Albany Medical Center in Albany, New York, clinical monitoring is implemented around the clock using a 192-channel Nihon-Kohden Neurofax monitoring system. Research recordings are made in collaboration with the Wadsworth Center of the New York State Department of Health in Albany. Signals from the ECoG electrodes are fed simultaneously to the research and the clinical systems via splitter connectors. To ensure that the clinical and research systems do not interfere with each other, the two systems typically use separate grounds. In fact, an epidural strip of electrodes is sometimes implanted to provide a ground for the clinical system. Whether research or clinical recording system, the grounding electrode is chosen to be distant from the predicted epileptic focus and from cortical areas of interest for the research. Our research system consists of eight synchronized 16-channel g.USBamp amplifier/digitizer units (g.tec, Graz, Austria). These were chosen because they are safety-rated and FDA-approved for invasive recordings, they have a very low noise-floor in the high-frequency range in which the signals of interest are found, and they come with an SDK that allows them to be integrated with custom-written research software. In order to capture the high-gamma signal accurately, we acquire signals at 1200Hz sampling rate-considerably higher than that of the typical EEG experiment or that of many clinical monitoring systems. A built-in low-pass filter automatically prevents aliasing of signals higher than the digitizer can capture. The patient's eye gaze is tracked using a monitor with a built-in Tobii T-60 eye-tracking system (Tobii Tech., Stockholm, Sweden). Additional accessories such as joystick, bluetooth Wiimote (Nintendo Co.), data-glove (5th Dimension Technologies), keyboard, microphone, headphones, or video camera are connected depending on the requirements of the particular experiment.
Data collection, stimulus presentation, synchronization with the different input/output accessories, and real-time analysis and visualization are accomplished using our BCI2000 software8,9. BCI2000 is a freely available general-purpose software system for real-time biosignal data acquisition, processing and feedback. It includes an array of pre-built modules that can be flexibly configured for many different purposes, and that can be extended by researchers' own code in C++, MATLAB or Python. BCI2000 consists of four modules that communicate with each other via a network-capable protocol: a Source module that handles the acquisition of brain signals from one of 19 different hardware systems from different manufacturers; a Signal Processing module that extracts relevant ECoG features and translates them into output signals; an Application module that delivers stimuli and feedback to the subject; and the Operator module that provides a graphical interface to the investigator.
A number of different experiments may be conducted with any given patient. The priority of experiments will be determined by the location of the particular patient's electrodes. However, we usually begin our experimentation using the SIGFRIED (SIGnal modeling For Realtime Identification and Event Detection) mapping method, which detects and displays significant task-related activity in real time. The resulting functional map allows us to further tailor subsequent experimental protocols and may also prove as a useful starting point for traditional mapping by electrocortical stimulation (ECS).
Although ECS mapping remains the gold standard for predicting the clinical outcome of resection, the process of ECS mapping is time consuming and also has other problems, such as after-discharges or seizures. Thus, a passive functional mapping technique may prove valuable in providing an initial estimate of the locus of eloquent cortex, which may then be confirmed and refined by ECS. The results from our passive SIGFRIED mapping technique have been shown to exhibit substantial concurrence with the results derived using ECS mapping10.
The protocol described in this paper establishes a general methodology for gathering human ECoG data, before proceeding to illustrate how experiments can be initiated using the BCI2000 software platform. Finally, as a specific example, we describe how to perform passive functional mapping using the BCI2000-based SIGFRIED system.

Watch this Scientific Journal Video about Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping at JoVE.com

Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

우리는 침략적 간질 모니터링을 진행하고 인간에서 연구 목적으로 electrocorticographic 신호를 수집하기위한 방법을 제시한다. 우리는 데이터 수집, 신호 처리 및 자극 프레 젠 테이션을 위해 BCI2000 소프트웨어 플랫폼을 사용하는 방법을 보여줍니다. 특히, 우리는 SIGFRIED, 실시간 기능적 뇌 맵핑을위한 BCI2000 기반 도구를 보여줍니다.

Neuroscientific 연구 및 실시간 기능성 두피 매핑을위한 인적 Electrocorticographic (ECoG) 신호를 녹음하기

Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), ...

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Research

JoVE Journal

Neuroscience

Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

25.6K 조회수.  New York State Department of Health. 우리는 침략적 간질 모니터링을 진행하고 인간에서 연구 목적으로 electrocorticographic 신호를 수집하기위한 방법을 제시한다. 우리는 데이터 수집, 신호 처리 및 자극 프레 젠 테이션을 위해 BCI2000 소프트웨어 플랫폼을 사용하는 방법을 보여줍니다. 특히, 우리는 SIGFRIED, 실시간 기능적 뇌 맵핑을위한 BCI2000 기반 도구를 보여줍니다.

비디오: Recording Human Electrocorticographic ECoG Signals for Neuroscientific Research and Real-time Functional Cortical Mapping

Functional Mapping with Simultaneous MEG and EEG

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the processing of simple sensory stimuli. We will use somatosensory stimuli to locate the hand somatosensory areas, auditory stimuli to locate the auditory cortices, visual stimuli in four quadrants of the visual field to locate the early visual areas. These type of experiments are used for functional mapping in epileptic and brain tumor patients to locate eloquent cortices. In basic neuroscience similar experimental protocols are used to study the orchestration of cortical activity. The acquisition protocol includes quality assurance procedures, subject preparation for the combined MEG/EEG study, and acquisition of evoked-response data with somatosensory, auditory, and visual stimuli. We also demonstrate analysis of the data using the equivalent current dipole model and cortically-constrained minimum-norm estimates. Anatomical MRI data are employed in the analysis for visualization and for deriving boundaries of tissue boundaries for forward modeling and cortical location and orientation constraints for the minimum-norm estimates.

We use magnetoencephalography (MEG) and electroencephalography (EEG) to map brain areas involved in the processing of simple sensory stimuli.

동시 MEG와 EEG와 기능 매핑

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the ...

연구

신경과학

Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis

The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar tasks. Participants' behavior during task performance in an fMRI scanner can then be correlated to the brain activity using the blood-oxygen-level-dependent signal. We measure behavior to be able to sort correct trials, where the subject performed the task correctly and then be able to examine the brain signals related to correct performance. Conversely, if subjects do not perform the task correctly, and these trials are included in the same analysis with the correct trials we would introduce trials that were not only for correct performance. Thus, in many cases these errors can be used themselves to then correlate brain activity to them. We describe two complementary tasks that are used in our lab to examine the brain during suppression of an automatic responses: the stroop1 and anti-saccade tasks. The emotional stroop paradigm instructs participants to either report the superimposed emotional 'word' across the affective faces or the facial 'expressions' of the face stimuli1,2. When the word and the facial expression refer to different emotions, a conflict between what must be said and what is automatically read occurs. The participant has to resolve the conflict between two simultaneously competing processes of word reading and facial expression. Our urge to read out a word leads to strong 'stimulus-response (SR)' associations; hence inhibiting these strong SR's is difficult and participants are prone to making errors. Overcoming this conflict and directing attention away from the face or the word requires the subject to inhibit bottom up processes which typically directs attention to the more salient stimulus. Similarly, in the anti-saccade task3,4,5,6, where an instruction cue is used to direct only attention to a peripheral stimulus location but then the eye movement is made to the mirror opposite position. Yet again we measure behavior by recording the eye movements of participants which allows for the sorting of the behavioral responses into correct and error trials7 which then can be correlated to brain activity. Neuroimaging now allows researchers to measure different behaviors of correct and error trials that are indicative of different cognitive processes and pinpoint the different neural networks involved.

The goal of our research is to correlate behavior to brain activity. Accurate behavioral measures and imaging techniques allow us to elucidate brain-behavior relationships.

인간의 전두엽 피질에서 fMRI 신호에 행동 응답을 연관 : 작업 분석을 사용하여인지 과정을 검토

The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar ...

Functional Calcium Imaging in Developing Cortical Networks

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in intact spinal cord, brainstem, retina, cortex and dissociated neuronal culture preparations. During periods of spontaneous activity, neurons depolarize to fire single or bursts of action potentials, activating many ion channels. Depolarization activates voltage-gated calcium channels on dendrites and spines that mediate calcium influx. Highly synchronized electrical activity has been measured from local neuronal networks using field electrodes. This technique enables high temporal sampling rates but lower spatial resolution due to integrated read-out of multiple neurons at one electrode. Single cell resolution of neuronal activity is possible using patch-clamp electrophysiology on single neurons to measure firing activity. However, the ability to measure from a network is limited to the number of neurons patched simultaneously, and typically is only one or two neurons. The use of calcium-dependent fluorescent indicator dyes has enabled the measurement of synchronized activity across a network of cells. This technique gives both high spatial resolution and sufficient temporal sampling to record spontaneous activity of the developing network.
A key feature of newly-forming cortical and hippocampal networks during pre- and early postnatal development is spontaneous, synchronized neuronal activity (Katz &amp; Shatz, 1996; Khaziphov &amp; Luhmann, 2006). This correlated network activity is believed to be essential for the generation of functional circuits in the developing nervous system (Spitzer, 2006). In both primate and rodent brain, early electrical and calcium network waves are observed pre- and postnatally in vivo and in vitro (Adelsberger et al., 2005; Garaschuk et al., 2000; Lamblin et al., 1999). These early activity patterns, which are known to control several developmental processes including neuronal differentiation, synaptogenesis and plasticity (Rakic &amp; Komuro, 1995; Spitzer et al., 2004) are of critical importance for the correct development and maturation of the cortical circuitry.
In this JoVE video, we demonstrate the methods used to image spontaneous activity in developing cortical networks. Calcium-sensitive indicators, such as Fura 2-AM ester diffuse across the cell membrane where intracellular esterase activity cleaves the AM esters to leave the cell-impermeant form of indicator dye. The impermeant form of indicator has carboxylic acid groups which are able to then detect and bind calcium ions intracellularly.. The fluorescence of the calcium-sensitive dye is transiently altered upon binding to calcium. Single or multi-photon imaging techniques are used to measure the change in photons being emitted from the dye, and thus indicate an alteration in intracellular calcium. Furthermore, these calcium-dependent indicators can be combined with other fluorescent markers to investigate cell types within the active network.

Spontaneous activity of developing neuronal networks can be measured using AM-ester forms of calcium-sensitive indicator dyes. Changes in intracellular calcium, indicating neuronal activation, are detected as transient changes in indicator fluorescence with one- or two-photon imaging. This protocol can be adapted for a range of developmentally-dependent neuronal networks in vitro.

두피 네트워크 개발에 기능성 칼슘 이미징

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in ...

Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery. Here we provide useful information for surgeons who are learning the process of implanting electrode systems. We demonstrate the implantation procedure of both a penetrating and a surface electrode. The surgical process is described from start to finish, including detailed descriptions of each step throughout the procedure. It should also be noted that this video guide is focused towards procedures conducted in rodent models and other small animal models. Modifications of the described procedures are feasible for other animal models.

We provide useful information for surgeons who are learning the process of implanting chronic neural recording electrodes. Techniques for both penetrating and surface electrode systems are described in a rodent animal model.

단일 유닛 활동과 Electrocorticographic 신호를 녹음하기 위해 만성 신경 전극 외과 이식

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery.  Here we provide useful information for ...

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon measuring activity on the surface of cerebral cortex rather than in subcortical regions such as midbrain and brainstem. Subcortical fMRI must overcome two challenges: spatial resolution and physiological noise. Here we describe an optimized set of techniques developed to perform high-resolution fMRI in human SC, a structure on the dorsal surface of the midbrain; the methods can also be used to image other brainstem and subcortical structures.
High-resolution (1.2 mm voxels) fMRI of the SC requires a non-conventional approach. The desired spatial sampling is obtained using a multi-shot (interleaved) spiral acquisition1. Since, T2* of SC tissue is longer than in cortex, a correspondingly longer echo time (TE ~ 40 msec) is used to maximize functional contrast. To cover the full extent of the SC, 8-10 slices are obtained. For each session a structural anatomy with the same slice prescription as the fMRI is also obtained, which is used to align the functional data to a high-resolution reference volume.
In a separate session, for each subject, we create a high-resolution (0.7 mm sampling) reference volume using a T1-weighted sequence that gives good tissue contrast. In the reference volume, the midbrain region is segmented using the ITK-SNAP software application2. This segmentation is used to create a 3D surface representation of the midbrain that is both smooth and accurate3. The surface vertices and normals are used to create a map of depth from the midbrain surface within the tissue4.
Functional data is transformed into the coordinate system of the segmented reference volume. Depth associations of the voxels enable the averaging of fMRI time series data within specified depth ranges to improve signal quality. Data is rendered on the 3D surface for visualization.
In our lab we use this technique for measuring topographic maps of visual stimulation and covert and overt visual attention within the SC1. As an example, we demonstrate the topographic representation of polar angle to visual stimulation in SC.

This article describes techniques to perform high-resolution functional magnetic resonance imaging with 1.2 mm sampling in human midbrain and subcortical structures using a 3T scanner. Use of these techniques to resolve topographic maps of visual stimulation in the human superior colliculus (SC) is given as an example.

인간 Midbrain위한 고해상도 기능성 자기 공명 영상 방법

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon ...

Mapping Cortical Dynamics Using Simultaneous MEG/EEG and Anatomically-constrained Minimum-norm Estimates: an Auditory Attention Example

Magneto- and electroencephalography (MEG/EEG) are neuroimaging techniques that provide a high temporal resolution particularly suitable to investigate the cortical networks involved in dynamical perceptual and cognitive tasks, such as attending to different sounds in a cocktail party. Many past studies have employed data recorded at the sensor level only, i.e., the magnetic fields or the electric potentials recorded outside and on the scalp, and have usually focused on activity that is time-locked to the stimulus presentation. This type of event-related field / potential analysis is particularly useful when there are only a small number of distinct dipolar patterns that can be isolated and identified in space and time. Alternatively, by utilizing anatomical information, these distinct field patterns can be localized as current sources on the cortex. However, for a more sustained response that may not be time-locked to a specific stimulus (e.g., in preparation for listening to one of the two simultaneously presented spoken digits based on the cued auditory feature) or may be distributed across multiple spatial locations unknown a priori, the recruitment of a distributed cortical network may not be adequately captured by using a limited number of focal sources.
Here, we describe a procedure that employs individual anatomical MRI data to establish a relationship between the sensor information and the dipole activation on the cortex through the use of minimum-norm estimates (MNE). This inverse imaging approach provides us a tool for distributed source analysis. For illustrative purposes, we will describe all procedures using FreeSurfer and MNE software, both freely available. We will summarize the MRI sequences and analysis steps required to produce a forward model that enables us to relate the expected field pattern caused by the dipoles distributed on the cortex onto the M/EEG sensors. Next, we will step through the necessary processes that facilitate us in denoising the sensor data from environmental and physiological contaminants. We will then outline the procedure for combining and mapping MEG/EEG sensor data onto the cortical space, thereby producing a family of time-series of cortical dipole activation on the brain surface (or "brain movies") related to each experimental condition. Finally, we will highlight a few statistical techniques that enable us to make scientific inference across a subject population (i.e., perform group-level analysis) based on a common cortical coordinate space.

We use magneto- and electroencephalography (MEG/EEG), combined with anatomical information captured by magnetic resonance imaging (MRI), to map the dynamics of the cortical network associated with auditory attention.

동시 멕 / EEG와 해부학적인 몸의 구조 제약 최소 - 표준 견적을 사용하여 매핑 두피 역학 : 청각주의 예

Magneto- and electroencephalography (MEG/EEG) are neuroimaging techniques that provide a high temporal resolution particularly suitable to investigate the ...

Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal models, including monkeys, ferrets, bats, rodents, and cats. In order to draw suitable parallels between human and animal models of auditory function, it is important to establish a bridge between human functional imaging studies and animal electrophysiological studies. Functional magnetic resonance imaging (fMRI) is an established, minimally invasive method of measuring broad patterns of hemodynamic activity across different regions of the cerebral cortex. This technique is widely used to probe sensory function in the human brain, is a useful tool in linking studies of auditory processing in both humans and animals and has been successfully used to investigate auditory function in monkeys and rodents. The following protocol describes an experimental procedure for investigating auditory function in anesthetized adult cats by measuring stimulus-evoked hemodynamic changes in auditory cortex using fMRI. This method facilitates comparison of the hemodynamic responses across different models of auditory function thus leading to a better understanding of species-independent features of the mammalian auditory cortex.

Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging.

하이 필드의 fMRI를 사용하여 성인 고양이의 청각 피질의 기능적 이미징

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal ...

A Protocol for the Administration of Real-Time fMRI Neurofeedback Training

Neurologic disorders are characterized by abnormal cellular-, molecular-, and circuit-level functions in the brain. New methods to induce and control neuroplastic processes and correct abnormal function, or even shift functions from damaged tissue to physiologically healthy brain regions, hold the potential to dramatically improve overall health. Of the current neuroplastic interventions in development, neurofeedback training (NFT) from functional Magnetic Resonance Imaging (fMRI) has the advantages of being completely non-invasive, non-pharmacologic, and spatially localized to target brain regions, as well as having no known side effects. Furthermore, NFT techniques, initially developed using fMRI, can often be translated to exercises that can be performed outside of the scanner without the aid of medical professionals or sophisticated medical equipment. In fMRI NFT, the fMRI signal is measured from specific regions of the brain, processed, and presented to the participant in real-time. Through training, self-directed mental processing techniques, that regulate this signal and its underlying neurophysiologic correlates, are developed. FMRI NFT has been used to train volitional control over a wide range of brain regions with implications for several different cognitive, behavioral, and motor systems. Additionally, fMRI NFT has shown promise in a broad range of applications such as the treatment of neurologic disorders and the augmentation of baseline human performance. In this article, we present an fMRI NFT protocol developed at our institution for modulation of both healthy and abnormal brain function, as well as examples of using the method to target both cognitive and auditory regions of the brain.

The ability to induce and/or control neural plasticity may be critical in future treatments for neurologic disorders and the recovery from brain injury. In this paper, we present a protocol on the use of neurofeedback training with functional magnetic resonance imaging to modulate human brain function.

관리의 실시간 fMRI Neurofeedback 훈련에 대 한 프로토콜

Neurologic disorders are characterized by abnormal cellular-, molecular-, and circuit-level functions in the brain. New methods to induce and control ...

Chronic Implantation of Whole-cortical Electrocorticographic Array in the Common Marmoset

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent development of thin, flexible ECoG electrodes has enabled conduction of stable recordings of large-scale cortical activity. We have developed a whole-cortical ECoG array for the common marmoset. The array continuously covers almost the entire lateral surface of cortical hemisphere, from the occipital pole to the temporal and frontal poles, and it captures whole-cortical neural activity in one shot. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain. Marmosets have two advantages regarding ECoG recordings, one being the homologous organization of anatomical structures in humans and macaques, including frontal, parietal, and temporal complexes. The other advantage is that the marmoset brain is lissencephalic and contains a large number of complexes, which are more difficult to access in macaques with ECoG, that are exposed to the brain surface.These features allow direct access to most cortical areas beneath the surface of the brain. This system provides an opportunity to investigate global cortical information processing with high resolutions at a sub-millisecond order in time and millimeter order in space.

We have developed a whole-cortical electrocorticographic array for the common marmoset that continuously covers almost the entire lateral surface of cortex, from the occipital pole to the temporal and frontal poles. This protocol describes a chronic implantation procedure of the array in the epidural space of the marmoset brain.

일반적인 마모 셋에 전체 피 질 Electrocorticographic 배열의 만성 이식

Electrocorticography (ECoG) allows the monitoring of electrical field potentials from the cerebral cortex with high spatiotemporal resolution. Recent ...

Real-Time fMRI Brain Mapping in Animals

Dynamic fMRI responses vary largely according to the physiological conditions of animals either under anesthesia or in awake states. We developed a real-time fMRI platform to guide experimenters to monitor fMRI responses instantaneously during acquisition, which can be used to modify the physiology of animals to achieve desired hemodynamic responses in animal brains. The real-time fMRI set-up is based on a 14.1T preclinical MRI system, enabling the real-time mapping of dynamic fMRI responses in the primary forepaw somatosensory cortex (FP-S1) of anesthetized rats. Instead of a retrospective analysis to investigate confounding sources leading to the variability of fMRI signals, the real-time fMRI platform provides a more effective scheme to identify dynamic fMRI responses using customized macro-functions and a common neuroimage analysis software in the MRI system. Also, it provides immediate troubleshooting feasibility and a real-time biofeedback stimulation paradigm for brain functional studies in animals.

Animal brain functional mapping can benefit from the real-time functional magnetic resonance imaging (fMRI) experimental set-up. Using the latest software implemented in the animal MRI system, we established a real-time monitoring platform for small animal fMRI.

동물의 실시간 fMRI 뇌 매핑

Dynamic fMRI responses vary largely according to the physiological conditions of animals either under anesthesia or in awake states. We developed a ...