Are the Local Blood Oxygen Level–Dependent (BOLD) Signals Caused by Neural Stimulation Response Dependent on Global BOLD Signals Induced by Hypercapnia in the Functional MR Imaging Experiment? Experiments of Long-Duration Hypercapnia and Multilevel Carbon Dioxide Concentration

^aDepartment of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, ROC
^bDepartment of Electrical Engineering, National Taiwan University, Taipei, Taiwan, ROC
^cDepartment of Radiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan, ROC
^dSection of Radiology, Hualien Armed Forces General Hospital, Hualien, Taiwan, ROC
^eDepartment of Electrical Engineering, National Taiwan University of Sciences and Technology, Taipei, Taiwan, ROC
^fDivision of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan, ROC
^gSection of General Surgery, Department of Surgery, Hualien Armed Forces General Hospital, Hualien, Taiwan ROC
^hInstitute of Aerospace Medicine, National Defense Medical Center, Taipei, Taiwan, ROC

Please address correspondence to Chun-Jung Juan, MD, Visiting Staff, Department of Radiology, Tri-Service General Hospital and National Defense Medical Center, No 325, Cheng-Kung Rd, Neihu, Taipei, Taiwan, ROC; e-mail: peterjuancj{at}yahoo.com.tw