Joseph B. Hopfinger is Professor of Psychology and Neuroscience at the University of North Carolina at Chapel Hill, USA, and Co-Editor-in-Chief of the journal Cognitive Neuroscience. He studies the neural mechanisms of attention and plasticity, using event-related potentials, functional MRI, and transcranial alternating current stimulation. Scott D. Slotnick is Professor of Psychology and Neuroscience at Boston College, USA, Co-Editor-in-Chief of Cognitive Neuroscience, and author of Controversies in Cognitive Neuroscience and Cognitive Neuroscience of Memory. He employs functional magnetic resonance imaging, electroencephalography, and transcranial magnetic stimulation to investigate brain mechanisms underlying memory and attention.