It is a crucial cognitive skill to select the relevant ones and exclude the irrelevant ones from all the stimuli we are exposed to in our constantly changing visual environment. While the long-standing early-late selection debates on the efficient attentional selection are still relevant, a hybrid theory was proposed by Lavie and Tsal (1994). Perceptual load theory is similar to the early selection approach in that it emphasizes limited capacity, while it is similar to late selection approaches in that it emphasizes automatic processing. In line with the theory, distractor processing depends on the task-relevant perceptual load. As perceptual load increases, unrelated stimuli can easily be excluded from the attention filter; because the capacity is full. The distractor interference effect is inevitable if the perceptual load is not high enough to fill the restricted capacity. According to the theory, the perceptual load is a key factor of the locus of selection. Although many support studies have been carried out after the theory was supposed, the number of studies inconsistent with the theory's assumptions, especially in recent years, cannot be ignored. Diverse studies have shown the importance of other factors in selective attention, such as salience, proximity, similarity, and dilution effect. In conclusion, despite being an important factor, the perceptual load is not the primary determinant in efficient attentional selection.
Perceptual load, selective attention, visual search, efficient attentional selection