Abstract
Here we propose a mathematical model with the combination of top-down and bottom-up effects applying in attentional capture. This model contains two stages, the selection stage and the decision-making stage. In each iteration, items change their activation values according to top-down and bottom-up weightings at the selection stage. We apply center-facilitation-surround-inhibition mechanism on the assignment of the weightings. The item facilitates itself according to its current activation value, and the facilitation is larger when the current activation value is low and smaller when the activation value is high. On the other hand, the item inhibits other items according to both the activation value of the item and the activation value of the inhibited item. The inhibition is smaller if the activation values of both items are low and larger if they are high. At the decision stage a response competition process is implemented, where each response has its own decision value. The decision is made if some activation value reaches the selection threshold and the decision value reaches the decision threshold. If no decision is made, the iteration will reenter the selection stage, and the iterations repeat until a decision is made. The activation map is reset after the decision stage. With this model, a number of empirical data using the spatial cuing task can be simulated. When the cue-to-target onset asynchrony is set to be zero, attentional capture using the visual search task can also be simulated. The model provides theoretical implications as to the interactions between top-down and bottom-up components in attentional selection.