Abstract: The attentional boost effect (ABE) refers to the counter-intuitive finding that the detection of infrequent targets in a divided-attention condition enhances memory of images co-occurring with targets, as compared with images co-occurring with frequent distractors (Swallow & Jiang, 2010). Previous studies have shown that the ABE also applies to verbal materials but had small or no effect on low-frequency (LF) words or orthographically distinctive (OD) words. The present study is to test whether the ABE be moderated by the unusual properties of stimuli, by manipulating another distinctive property of the to-be-remembered stimuli: negative emotion. The present study includes two experiments. In Experiment 1, participants encoded a long sequence of neutral or negative words or images (500ms/ item), while simultaneously monitored the color of a small circle (100ms) located under each word or a small square (100ms) located at the center of each image. Participants were required to remember the words or images and pressed a spacebar whenever they detected occasional targets (red circles or black squares) among more frequent distractors (green circles or white squares). In a later recognition test, stimuli co-occurring with targets and distractors were mixed with new stimuli for an old/new judgment. Experiment 2 further manipulated the arousal of the negative stimuli, and was divided into two conditions: low-arousal and high-arousal negative stimuli paired with targets and distractors. Thirty-four undergraduates participated in Experiment 1 and thirty undergraduates participated in Experiment 2. All experimental procedures were programmed in Presentation 0.71, and run on a DELL Dimension 8200 computer with a 19? monitor (1024×768 pixels). The main results were as following: (1) In Experiment 1, the ABE was significant for neutral stimuli [F(1,33)=39.45, p<.001] and for negative stimuli [F(1,33)=9.99, p=.003], with the recognition being better for target-paired stimuli than for distractor-paired stimuli. More important, the ABE was smaller for negative-emotional stimuli than for neutral-emotional stimuli [F(1,33)=9.808, p=.004, ηp2=.229], indicating the moderating influence of negative emotion on the ABE. (2) In Experiment 2, the ABE was significant for low-arousal negative stimuli [F(1,29)=14.04, p=.001], whereas there was no hint of an ABE for high-arousal negative stimuli [F(1,29)=.10, p=.754], that is, the ABE had no effect on the high-arousal negative stimuli. These results confirm and extend previous results suggesting that the ABE could be moderated by the distinctiveness of memory materials. The unusual nature of negative stimuli attracts greater attentional resources during the encoding. As a consequence, the transient attentional enhancement occurring as a consequence of target detection in the ABE paradigm might have minimal or no effects on these distinctive items.

Key words: Attentional Boost Effect, negative emotion, target-detection task, memory

摘要： 近期研究发现，目标探测性质的注意分散并不会削弱，甚至会提高与之同时进行的记忆任务成绩，表现出注意促进效应（ABE），但该效应可能会受到记忆材料独特性的调节。为了验证该假设，本文采用负性刺激为记忆材料，以目标探测任务为干扰任务，探讨负性情绪对ABE的调节。结果发现，与中性材料相比，负性材料的ABE有所减弱；而高唤醒的负性材料则没有表现出任何的ABE。可见目标探测所产生的促进作用会受到背景材料是否具有独特性的限制。

关键词: 注意促进效应, 负性情绪, 目标探测任务, 记忆