Premium
Spatial and temporal differentiation of fMRI BOLD response in primary visual cortex of human brain during sustained visual simulation
Author(s) -
Chen Wei,
Zhu XiaoHong,
Kato Toshinori,
Andersen Peter,
Uǧurbil Kâmil
Publication year - 1998
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910390404
Subject(s) - visual cortex , neuroscience , stimulation , functional magnetic resonance imaging , visual field , psychology , cortex (anatomy) , phosphene , photic stimulation , visual perception , transcranial magnetic stimulation , perception
The blood oxygenation level dependent (BOLD) response during sustained visual stimulation has been studied by several groups using fMRI with controversial conclusions. This issue was investigated for the human brain at high (4 Tesla) magnetic field strength using a flashing goggle at 8 Hz. The results demonstrate that the overall BOLD response in the primary visual cortex has an initial overshoot after the onset of visual stimulation and an undershoot after the termination of visual stimulation. A significant and positive BOLD response, however, remains constant between the initial and terminal transient responses. The temporal BOLD responses in the primary visual cortex were spatially dependent. The regions identified as draining veins in images displayed proportionately larger initial and terminal transient responses, whereas regions devoid of such vessels and associated mainly with parenchyma exhibited a more time‐independent BOLD response. These results reveal that the BOLD effect and, presumably, the uncoupling between cerebral blood flow and cerebral metabolic rate of oxygen consumption, are maintained in the primary visual cortex during sustained visual stimulation, and the temporal characteristics of the BOLD effect are spatially dependent.