Future of functional brain imaging

To examine the living human brain's sensory, motor and cognitive interactions and to understand how activities in anatomically distinct neural processing regions are orchestrated to perform complex tasks represents a future challenge to neuroscientists. Until recently, functional brain imaging data have been constrained by the severely limited spatial (5-15 mm) and temporal resolution (from a few seconds to minutes) of the nuclear medicine methods, single-photon emission tomography (SPET) and positron emission tomography (PET). The advent of new non-invasive, fast imaging methods - functional magnetic resonance imaging (fMRI), serial X-ray computed tomography ('cine' CT) and magnetoencephalography (MEG) - has created a need for a survey to compare these techniques with conventional SPET and PET. Each technique has unique advantages and simultaneously serious limitations. No method has achieved a clear supremacy in functional brain imaging. (orig.)