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Understanding the human brain is one of the greatest scientific quests of all time. Although this endeavor has engaged genera-tions of scientists, the available methods were very limited until recently. Investigators could examine people with brain injuries, measure brain structure post mortem, make infer-ences from behavior, or extrapolate from invasive work in ani-mals. Even the tools used to examine the brain in action in healthy people in the latter part of the 20th century had major limitations. Electrophysiological measurements of brain activ-ity on the scalp could record rapid fluctuations but could not pinpoint the source of these signals. Positron emission tomog-raphy (PET) allowed scientists to measure blood flow as an index of local brain activity, and to trace molecules that bind to specific receptors, but it requires injecting people with a radioactive isotope, thus limiting the temporal and spatial res-olution according to the decay properties of the isotope. Tech-niques that captured activity in the human brain with high spatial and temporal resolution were lacking (Churchland & Sejnowski, 1988). Thus, the development of functional mag-netic resonance imaging (fMRI), which offered temporal reso-lution on the order of seconds and spatial resolution on the order of millimeters, opened up an exciting new landscape for exploration. The first fMRI study was published in 1992 (Kwong et al., 1992), and multiple others were presented that year at meet-ings (for review, see Frahm, Merboldt, & Hanicke, 1993). The excitement around this new method was explosive. After vali-dating the method by finding known basic sensory and motor regions, scientists quickly moved on to use fMRI to accom-plish stunning new feats, including mapping the human retino-topic cortex (Engel et al., 1994), demonstrating the neural correlates of visual motion aftereffects in humans (Tootell et al., 1995), and demonstrating attentional modulation of basic perceptual processing (O’Craven, Rosen, Kwong, Treis