Hemodynamic and electroencephalographic responses to illusory figures: recording of the evoked potentials during functional MRI.
The feasibility of recording event-related potentials (ERP) during functional MRI (fMRI) scanning using higher level cognitive stimuli was studied. Using responses to illusory figures in a visual oddball task, evoked potentials were obtained with their expected configurations and latencies. A rapid stimulation scheme using randomly varied trial lengths was employed, and class-wise characteristics of the hemodynamic response were obtained by a nonlinear analysis of the fMRI time series. Implications and limitations of conducting combined ERP-fMRI experiments using higher level cognitive stimuli are discussed. EEG/fMRI results revealed a sequential activation of striate and extrastriate occipital cortex along the ventral path of object processing for Kanizsa figures. Interestingly, Kanizsa figures activated the human motion area MT. Targets resulted in activations of frontal and parietal cortex which were not activated for standard stimuli.
Kruggel
F
F
Max-Planck-Institute of Cognitive Neuroscience, Stephanstrasse 1, 04103 Leipzig, Germany.
Herrmann
C S
CS
Wiggins
C J
CJ
von Cramon
D Y
DY
D000328:Adult; D001143:Arousal / Q000502:physiology; D001931:Brain Mapping; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009778:Occipital Lobe / Q000098:blood supply / Q000502:physiology*; D009903:Optical Illusions / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000098:blood supply / Q000502:physiology