Abstract
The visual environment is often stable, but some aspects may change over time. For example, the furniture in the room may be re-arranged, and new furniture may replace old ones. The challenge for the mind is thus to update knowledge about the environment in light of new information. Here we examine whether the attentional bias to regularities can be shifted in the presence of new stimuli. The experiment consists of two halves. In the first half, observers viewed four simultaneous streams of shapes. The stream in one 'structured' location contained triplets, the shapes in one 'random' location were randomized, and a gray square appeared in each of the two 'neutral' locations. Occasional search arrays were presented where the target appeared randomly at one of the four locations. In the second half, everything was the same except that the stream in the structured or the random location may change. Several changes occurred across four conditions: (1) the structured stream became random; (2) the random stream became structured; (3) the random stream now contained new random shapes; and (4) the random stream now contained new structured shapes. In the baseline condition, no change ever occurred. We found that in all conditions, during the first half of the experiment, target discrimination was reliably faster for targets at structured vs. random or neutral locations, suggesting that attention was drawn to the structured location. In the second half, regardless of condition, target discrimination was again reliably faster for targets at structured vs. random or neutral locations. This suggests that attention persisted at the previously structured location, even though the stream was no longer structured, or newly structured stream or new shapes emerged in another location. These findings reveal the robustness and persistence of the attentional bias to regularities even in the presence of novel stimuli.
Meeting abstract presented at VSS 2014