Abstract
Probability cueing effect refers to an attentional bias toward a highly probable target location. Previous studies have shown that such bias occurs through accumulation of incidents over time and stays robust when once learned (Jiang, Swallow, Rosenbaum, & Herzig, 2013). However, the probability distribution in the real world could dynamically change across time and it would be beneficial for the visual system if the bias can be readjusted. Here, we investigated whether a gradual change in the probability distribution can influence the learning of a spatial bias. Participants were instructed to search for a target among multiple distractors under acondition where a target was more likely to appear in one of four quadrants in the display. For the half of the participants, the probability of target presence in the frequent quadrant gradually decreased until the probability distribution reachedeven for all four quadrants (gradual group). For the remaining participants, the probability distribution remained the same throughout the learning phase (constant group). Importantly, the total number of attentional shifts to the target-frequent quadrant was kept the same for both gradual and constant groups. To test whether participants acquired statistical knowledge of target locations, we asked them to perform a search task in which a target appeared equally often in all four quadrants. Results showed that the spatial bias was weakened in the gradual group than in the constant group even though both groups experienced the same amount of statistical information during the learning phase. In sum, we found that the learning of statistical knowledge can be modulated through gradual signal change toward a frequent target location. The current finding suggests that the temporal change of experience is more likely to have an impact on the learning of a spatial bias than the total amount of experience.
Acknowledgement: 18-BR-01-07 & IBS-R001-D1-2018-b01