image: Measuring neuronal activity exclusively from the target region. Low-level visual areas such as the primary visual cortex shows retinotopy, where adjacent points in the visual field correspond to adjacent points in the brain. Functional magnetic resonance imaging has high enough spatial resolution to take advantage of this property and measure blood-oxygen-level-dependent (BOLD) signal from regions of the primary visual cortex which corresponds to the “unpatterned donut region” of the stimulus. This made it possible for us to extract neuronal activity arising exclusively from the physically constant target visual stimulus (a part of the left grating which matches the "doughnut region"), while the target became perceptually visible or invisible depending on the contextual configuration. This image relates to a paper that appeared in the Nov. 11, 2011, issue of Science, published by AAAS. The paper, by Dr. M. Watanabe of Max Planck Institute for Biological Cybernetics in Tuebingen, Germany, and colleagues, was titled, "Attention But Not Awareness Modulates the BOLD Signal in the Human V1 During Binocular Suppression." view more
Credit: Image © <i>Science</i>/AAAS