How does voluntary attention to one attribute of a visual stimulus affect the neural processing of that stimulus? We used functional magnetic resonance imaging to examine the attentional modulation of neural activity in the human homolog of the MT-MST complex, which is known to be involved in the processing of visual motion. Using a visual stimulus containing both moving and stationary dots, we found significantly more MT-MST activation when subjects attended to the moving dots than when they attended to the stationary dots, even though the visual stimulus was identical during the two conditions.