Abstract:

Feature-based attention (FBA) is the ability that observers can direct their attention to a specific feature dimension or value. In the attentional focus, FBA can modulate the response of neurons in visual cortex: it selectively increases the responses of neurons encoding attended features while suppresses the responses of neurons encoding distracting features. Many studies found that this attentional modulation can spread outside the focus of attention, but the underlying mechanism of the global modulation of FBA (enhancement or suppression) is still controversial. The global enhancement mechanism and the global suppression mechanism are different in time courses and may play distinctive roles in visual information processing. Compared to the global enhancement mechanism, the global suppression mechanism seems more likely to be influenced by experimental designs and parameters. Future studies are needed to investigate under what conditions the global suppression mechanism takes effect and to further disassociate these two global mechanisms in the process of feature-based attention.

Key words: feature-based attention, global modulation, global enhancement, global suppression