Temporal encoded orientation maps with CBV-weighted fMRI in primary visual cortex.
Moon C, Fukuda H, Kim S
Dept. of Neurobiology
In order to increase the sensitivity of orientation-selective fMRI signals, temporally-encoded continuous stimulation was used with an ultrahigh magnetic field. Iso-orientation maps of fMRI were compared with those of optical imaging of intrinsic signal with 570nm wavelength in the same anesthetized cats. Location of active columns in the fMRI maps well matched with that of the optical imaging maps. This implies that an increase in blood volume (plasma and red blood cells) should occur in microvessels confined to the iso-orientation column. With the confirmed fMRI, functional architecture can be mapped in the brain where optical imaging can not be used.