Functional Mapping of the Human Visual Cortex by Magnetic Resonance Imaging

TLDR

Knowledge of regional cerebral hemodynamics is widely applied in physiology and clinical assessment because of the close link between function, metabolism, and localized blood supply. A magnetic‑resonance technique was developed for quantitative imaging of cerebral hemodynamics, enabling measurement of regional cerebral blood volume during resting and activated cognitive states. The technique produced the first functional MR maps of human visual cortex activation, revealing a 32 ± 10 % increase in blood volume in the primary visual cortex during photic stimulation, with reported center‑of‑mass coordinates and linear extents within the calcarine fissure.

Abstract

Knowledge of regional cerebral hemodynamics has widespread application for both physiological research and clinical assessment because of the well-established interrelation between physiological function, energy metabolism, and localized blood supply. A magnetic resonance technique was developed for quantitative imaging of cerebral hemodynamics, allowing for measurement of regional cerebral blood volume during resting and activated cognitive states. This technique was used to generate the first functional magnetic resonance maps of human task activation, by using a visual stimulus paradigm. During photic stimulation, localized increases in blood volume (32 ± 10 percent, n = 7 subjects) were detected in the primary visual cortex. Center-of-mass coordinates and linear extents of brain activation within the plane of the calcarine fissure are reported.