Cover legend: Adult rats were trained to discriminate changes independent sound parameters, either frequency or intensity, within an identical set of auditory stimuli that varied in both dimensions. Cochleotopic and ampliotopic maps were delineated in the primary auditory cortex and a secondary auditory field at the conclusion of training. The color of each tile in the cochleotopic maps shown on the cover represents the preferred tone frequency for each position in the cortical map. The area of the cochleotopic and ampliotopic maps allocated to the target frequency or intensity changed according to the degree of perceptual improvement, but the change was restricted to the stimulus dimension to which the animal attended. These data demonstrate a role for top-down influences such as selective attention in the expression of adult sensory cortex plasticity. We appreciate the assistance of Ms. Melanie Bridges with the cover design. See article by Polley et al. this issue (pages 4970–4982).