Abstract: The low proportion of repeated trials in priming studies can trigger negative priming, but most of these studies used a single prime and conflicted probe paradigm which was thought to play a key role in triggering negative priming effect. Thus, those negative priming effects cannot be attributed only to the low proportion of repeated trials, for the conflicted probe can also play an important role on it. Moreover, the negative priming found in some studies using a single prime and only target paradigm have challenged the view that conflicted probe plays a key role in causing negative priming. However, these studies manipulated either ignore instruction or proportion and other factors simultaneously which cannot dissociate the real effects of the low proportion. In addition, Frings and Wentura (2006) speculated that repeatability of stimuli affected awareness of participants about correlation between prime and target, and it was harder to perceive this correlation by using a larger quantity of semantic-associated words than a limited number of repetitive words. Therefore, the size of stimulus set composed by semantically related words might also be a key factor in triggering negative priming effect, but they employed dual-prime and single-probe paradigm. The present study explores the characteristic of inhibitory control by manipulating the proportion of related trials and varying the size of the stimuli set in single prime and only target paradigm . In Experiment 1, the proportion of related trials was set to 20% or 80%, and Experiment 2 introduced two different sizes of stimuli set (i.e., 8 and 48) and tested their effects on inhibition. In Experiment 1, a total of 22 participants participated in the two-proportion blocks. And in Experiment 2, two different sizes of stimuli set were manipulated in between-subjects. Other two factors, including the prime condition and the proportion, were manipulated in within-subjects. Semantic negative priming was observed in 20% condition, in contrast, the positive priming effect was observed in 80% proportion condition in Experiment 1. Moreover，by analyzing the data from four blocks according to the experimental sequence, the pattern of negative priming was observed in four blocks in 20% condition, whereas the positive pattern was observed in four blocks in the 80% condition. In Experiment 2, for 20% condition, a reliable negative priming effect was observed when the quantity of stimuli set was 8; whereas a non-significant negative priming occurred when it was for 48. Regardless of small or large stimulus sets, the significantly positive priming effect was observed when the related proportion was high. The current study demonstrated that manipulation alone on the low proportion of related trials in a single prime and only target paradigm could trigger the inhibitory control, which was caused by the ignored strategies. In addition, when the proportion of related trials was low, the implementation of inhibition was subject to the size of stimuli set. Smaller stimulus set could trigger a greater inhibition, whereas the larger stimulus set could induce lower, or even could not induce inhibition. The current results supported the viewpoint that the more salient distractor could trigger stronger inhibition.

Key words: a single prime and only target paradigm, related proportion, inhibitory control, negative priming

摘要： 启动和探测刺激相同试次低比例时可出现类似负启动的抑制现象。本研究采用不同于以往研究的单一探测范式，并操纵相关项（启动与探测词语义相关）的比例及刺激集的大小研究这一抑制机制的特点。实验一在低比例时发现了显著的负启动效应。实验二在低比例时，发现小的刺激集能诱发负启动，而大的则不能。表明在单一探测范式中启动与探测相关试次的低比例确实能诱发抑制控制，该抑制控制由忽视策略所致，并受刺激集大小的影响，支持了干扰项的凸显能够诱发强抑制的观点。

关键词: 单一启动单一探测, 相关低比例, 抑制控制, 负启动效应