Cross-feature spread of global attentional modulation in human area MT+.

Feature-based attention affects the processing of the selected feature throughout the visual field. Here, we show that such global attentional modulation is not restricted to the attended feature but spreads to task-irrelevant features that are bound to the attended one. Attention to a color in one of the visual hemifields affected the processing of task-irrelevant motion in the other hemifield when it was associated with a stimulus that shared the attended color. This cross-feature global attentional selection increased the duration of the motion aftereffect and the strength of functional magnetic resonance imaging responses in the motion-sensitive area MT+, evoked by the task-irrelevant motion. These findings imply that features belonging to the same object are bound and selected jointly even outside the focus of attention.