Attention mechanisms underlying dual-color digital visual search based on Schulte grid: An event-related potential study

Background: Attention selection is considered to be determined by the perceptual load of cognitive tasks and attention resources that are assigned to processing-independent stimuli.

Methods: Using visual search paradigm and Schulte grid, the behavioral responses and event-related potential (ERP) of 27 pupils aged 8-11 (12 girls and 15 boys) were recorded. The subjects were asked to search for the numbers 1, 2, and 3 sequentially and locate the number 5 in the case of monochromatic (black) and bicolor (black-red) numbers.

Results: We found that the sequential search task took longer than the location search task (p < .05). Furthermore, both search tasks took longer in two-color conditions than in monochromatic conditions. However, as for sequential search and location search tasks, no significant intra-group difference was found. ERP data showed that there was significant difference between monochromatic and bichromatic conditions in locating search tasks (P2-P4: p < .05; T7: p < .05, T8: p < .05), but there was no significant difference in sequential search tasks.

Conclusions: Our results indicates that red will be interfered when searching for one number, but will not be interfered when searching for three numbers, which is related to the higher perceptual load of sequential search tasks and less attention resources than those used to interfere with stimulus processing.