关键词: 返回抑制, 颜色特征, 身份特征, 空间位置, 非空间特征

Abstract:

Previous research using Posner’s cuing paradigm has demonstrated that responding to targets at previously cued locations is slowed in comparison with responding to targets at uncued locations. This result has led to a space-based explanation of inhibition of return (IOR). Although non-spatial IOR has also been reported for years, it has not attracted much attention, and the role of non-spatial attributes in IOR remains a controversial issue. It has been shown that non-spatial IOR is confined only to the location of the cue and disappears when the cue and the target are presented at different locations. These findings imply a primary role of location in IOR. To control the role of location, the present study used a dynamic display in which a single- or dual- route tunnel was added to the dynamic cuing paradigm. The aim was to examine the role of non-spatial attributes in IOR when spatial location was either specific or ambiguous. Four experiments were conducted. The first two experiments investigated the role of color in IOR using the dynamic cuing paradigm combined with the single- and dual- route tunnels respectively. The last two experiments focused on the role of identity using methods similar to those of the first two experiments. In experiments 1 and 3, two objects entered the single-route tunnel at the same time, from the upper and lower (or, left and right) portals, after cuing one of them, and then exited from corresponding portals. Since each object left the tunnel from a known exit, spatial locations of the two objects were specific and reliable all the time. In experiment 2 and 4, the single-route tunnel was replaced by the dual-route tunnel. Two objects entered the tunnel in the same way as in experiments 1 and 3, but left the tunnel from two exits at random. The locations of objects became uncertain after moving: Thus spatial attribute was ambiguous in both experiment 2 and 4. Whether color or identity alone could support IOR was then investigated. In all experiments, the two objects were covered with neutral objects when they were moving out of the tunnel. In the target display, one of two neutral objects was removed, and the object behind this neutral object reoccurred. Participants were instructed to detect the reoccurrence as soon as possible. Four SOAs (stimulus onset asynchronies) between the cue and the target were used in each experiment. IOR was measured by the delay in responding to the target when the cue and target shared the same color or identity. In experiment 1, color repetition produced a facilitation effect at the shortest SOA and inhibitory effects at the two longest SOAs, implying that IOR occurred when objects went through the single-route tunnel. In other words, the role of color attribute in IOR was illustrated when spatial location was specific and reliable in a dynamic display. In experiment 2, a color-based repetition inhibitory effect was found at the longest SOA. This result suggested that color attribute could play an independent role in IOR when a dual-route tunnel was used and the spatial location was ambiguous. In both experiment 3 and 4, target detection was slowed at the longest SOA when the cue and target shared the same identity. Therefore the role of identity attribute in IOR was confirmed in the single- and dual- route tunnels In conclusion, the present study showed that in a dynamic display non-spatial attributes of objects, such as color and identity, could not only play an important role when spatial location is specific and reliable, but also an independent role when spatial location is ambiguous.

Key words: inhibition of return, color, identity, location, non-spatial attributes