颜色和形状工作记忆对非空间返回抑制效应的影响

为进一步考察非空间返回抑制效应是否受工作记忆内容的影响，分别采用颜色和形状工作记忆内容，通过两个实验考察了工作记忆对非空间返回抑制效应的影响。实验结果表明，在颜色和形状工作记忆条件下，均产生了颜色或形状返回抑制效应，并且颜色或形状返回抑制效应量之间均无显著差异，颜色和形状工作记忆内容只增加了判断靶刺激的反应时。研究结论对进一步认识工作记忆内容与非空间返回抑制效应之间的关系有重要参考价值。

The Effects of Color and Shape Working Memory on Non-spatial Inhibition of Return

Responding to a target that presented at the cued location is slower than responding to a target that presented at the uncued location. It reflected a well-known spatial inhibition of return (IOR) effect. Object-based IOR appeared when the target was displayed on the cued object. Recently, several studies found a kind of non-spatial IOR (e.g., color IOR and shape IOR). Previous researchers used the dual-task paradigm combining the typical IOR paradigm with some working memory (WM) tasks. They found that the spatial IOR would be eliminated when a spatial WM task was involved in the dual-task paradigm. However, the spatial IOR still existed when it contained a non-spatial WM task. They suggested that spatial IOR is partially modulated by the spatial WM system. Some studies have found that the shape IOR is modulated by the shape WM; the color IOR is modulated by the color WM, but not modulated by the shape WM. However, the evidences of the relationship between the non-spatial IOR and WM were still not sufficient. The purpose of the present study was to examine whether the non-spatial IOR (e.g., color IOR and shape IOR) was modulated by the WM tasks (e.g., shape and color WM tasks). Our hypotheses were that the color and shape IOR could not be modulated by the color or shape WM; the performances of target discrimination could be modulated by the color and shape WM.In Experiment 1, a 3 (WM conditions: without WM vs. color WM vs. shape WM) × 2 (color congruencies of the cue and target: congruent vs. incongruent) within-subjects design was adopted. The cue and target were color stimuli in this dual-task paradigm. In each trial, participants were firstly required to pay attention to the cue and conducted a WM task. Then they were instructed to discriminate the color of the target. In the last, there was a memory test for the WM task. The discriminating RTs and accuracy data were collected from 26 participants (8 males, 18 females, with mean age of 23.2±1.6). In Experiment 2, a 3 (WM conditions: without WM vs. color WM vs. shape WM) × 2 (shape congruencies of the cue and target: congruent vs. incongruent) within-subjects design was adopted. The same participants in Experiment 1 took part in the Experiment 2. The procedure was identical to the Experiment 1, but the cue and target were the shape stimuli. Participants were instructed to discriminate the shape of the target. The order of two experiments was random.The results revealed that: (1) in Experiment 1, color IOR was found in all WM conditions; in Experiment 2, shape IOR was found in all WM conditions; (2) the differences between the magnitude of color IOR in color WM and the magnitude of color IOR in shape WM were not reliable. The differences between the magnitude of shape IOR in color WM and the magnitude of shape IOR in shape WM were not reliable. But the discriminating RTs in the color and shape WM conditions were longer than it was in the without WM condition.In summary, the present study concluded that: (1) the color IOR and shape IOR existed in the color WM and shape WM conditions; (2) there was no difference between the magnitude of color IOR in color WM condition and the magnitude of color IOR in shape WM condition. There was no difference between the magnitude of shape IOR in color WM condition and the magnitude of shape IOR in shape WM condition. However, the color and shape WM tasks required an additional response time to discriminate the color or shape of the target relative to the condition without WM. Key words: working memory, non-spatial inhibition of return, color, shape