How does a subliminal cue influence object-based attention?

摘要

Mulckhuyse, Talsma, and Theeuwes (2007) have shown that a subliminal cue can capture attention to its location. In this study we investigated whether this kind of subliminal cue can cause object-based selection. According to the spreading hypothesis of object-based attention (e.g., Richard, Lee, & Vecera, 2008), a subliminal cue that can successfully capture attention to a specific location within an object should also cause attention to spread throughout the whole cued object. By adopting the two-rectangle method (Egly, Driver, & Rafal, 1994) and using an effective subliminal cue as in Mulckhuyse et al. (2007), we tested whether the same-object advantage (i.e., faster response to a target within a cued object than within a non-cued object) can be obtained as with the classic supra-threshold cue. The subliminal cue was a small patch appearing in one corner of the two rectangles, presented 16 ms earlier than the other patches shown in the other three corners, giving the impression that all four patches appeared simultaneously. Objective and subjective measures both indicated that participants were indeed unaware of the cue. We found that subliminal and supra-threshold cues caused different result patterns: a subliminal cue led to the different-object advantage, and the supra-threshold cue replicated the conventional same-object advantage. The fact that the subliminal cue did not lead to the same object advantage is inconsistent with the spreading hypothesis. Instead, we propose that a subliminal cue strengthens between-object links, which are coded primarily within the magnocellular to dorsal pathway that governs the visual guidance of action (e.g., Davis & Holmes, 2005; Humphreys, 1998).