Miller James R, Becker Mark W, Liu Taosheng
Department of Psychology, Michigan State University, East Lansing, MI 48824.
Department of Psychology, Michigan State University, East Lansing, MI 48824 ; Neuroscience Program, Michigan State University, East Lansing, MI 48824.
Vis cogn. 2014 Aug 1;22(7):920-947. doi: 10.1080/13506285.2014.936923.
We investigated the nature of the bandwidth limit in the consolidation of visual information into visual short-term memory. In the first two experiments, we examined whether previous results showing differential consolidation bandwidth for color and orientation resulted from methodological differences by testing the consolidation of color information with methods used in prior orientation experiments. We briefly presented two color patches with masks, either sequentially or simultaneously, followed by a location cue indicating the target. Participants identified the target color via button-press (Experiment 1) or by clicking a location on a color wheel (Experiment 2). Although these methods have previously demonstrated that two orientations are consolidated in a strictly serial fashion, here we found equivalent performance in the sequential and simultaneous conditions, suggesting that two colors can be consolidated in parallel. To investigate whether this difference resulted from different consolidation mechanisms or a common mechanism with different features consuming different amounts of bandwidth, Experiment 3 presented a color patch and an oriented grating either sequentially or simultaneously. We found a lower performance in the simultaneous than the sequential condition, with orientation showing a larger impairment than color. These results suggest that consolidation of both features share common mechanisms. However, it seems that color requires less information to be encoded than orientation. As a result two colors can be consolidated in parallel without exceeding the bandwidth limit, whereas two orientations or an orientation and a color exceed the bandwidth and appear to be consolidated serially.
我们研究了将视觉信息整合到视觉短期记忆中时带宽限制的本质。在前两个实验中,我们通过使用先前用于方向实验的方法测试颜色信息的整合,来检验先前显示颜色和方向的整合带宽存在差异的结果是否源于方法上的差异。我们用掩蔽短暂呈现两个颜色块,要么顺序呈现,要么同时呈现,随后给出一个指示目标的位置线索。参与者通过按键(实验1)或点击色轮上的位置(实验2)来识别目标颜色。尽管这些方法先前已证明两个方向是以严格串行的方式进行整合的,但在这里我们发现在顺序呈现和同时呈现条件下表现相当,这表明两种颜色可以并行整合。为了探究这种差异是源于不同的整合机制,还是源于具有不同特征的共同机制消耗了不同量的带宽,实验3顺序或同时呈现一个颜色块和一个有方向的光栅。我们发现在同时呈现条件下的表现低于顺序呈现条件,其中方向的受损程度比颜色更大。这些结果表明两种特征的整合共享共同机制。然而,似乎颜色编码所需的信息比方向少。因此,两种颜色可以并行整合而不超过带宽限制,而两个方向或一个方向与一种颜色则会超过带宽,似乎是串行整合的。