Department of Experimental Psychology, Ghent University, Ghent, Belgium.
Cognition. 2011 Jul;120(1):136-47. doi: 10.1016/j.cognition.2011.03.005. Epub 2011 Apr 12.
In this study, we investigate whether multiple digits can be processed at a semantic level without awareness, either serially or in parallel. In two experiments, we presented participants with two successive sets of four simultaneous Arabic digits. The first set was masked and served as a subliminal prime for the second, visible target set. According to the instructions, participants had to extract from the target set either the mean or the sum of the digits, and to compare it with a reference value. Results showed that participants applied the requested instruction to the entire set of digits that was presented below the threshold of conscious perception, because their magnitudes jointly affected the participant's decision. Indeed, response decision could be accurately modeled as a sigmoid logistic function that pooled together the evidence provided by the four targets and, with lower weights, the four primes. In less than 800ms, participants successfully approximated the addition and mean tasks, although they tended to overweight the large numbers, particularly in the sum task. These findings extend previous observations on ensemble coding by showing that set statistics can be extracted from abstract symbolic stimuli rather than low-level perceptual stimuli, and that an ensemble code can be represented without awareness.
在这项研究中，我们探究了是否可以在无意识的情况下，以串行或并行的方式，在语义层面上处理多个数字。在两项实验中，我们向参与者呈现了两个连续的四位数阿拉伯数字集。第一个集被掩蔽，作为第二个可见目标集的潜意识启动。根据指令，参与者必须从目标集中提取数字的平均值或总和，并将其与参考值进行比较。结果表明，参与者将请求的指令应用于整个低于意识感知阈值的数字集，因为它们的大小共同影响了参与者的决策。实际上，响应决策可以通过将四个目标提供的证据和四个启动器的证据以较低的权重进行汇总的 sigmoid 逻辑函数进行准确建模。在不到 800ms 的时间内，参与者成功地完成了加法和平均值任务，尽管他们倾向于过度重视大数字，尤其是在求和任务中。这些发现通过表明集合统计信息可以从抽象的符号刺激中提取，而不是从低级别的感知刺激中提取，并且可以在无意识的情况下表示集合代码，扩展了先前关于集合编码的观察。
