Does the experimenter presence affect working memory?

Recent studies suggest that social presence undermines performance in difficult tasks because the presence of others would automatically capture the attention needed to achieve these tasks. Here, we tested whether this attentional capture (caused by the experimenter presence) affects working memory. Several models suggest that maintenance in working memory relies on an attentional mechanism. Besides this mechanism, another nonattentional verbal rehearsal could also maintain verbal information. In experiment 1, we varied the presence of the experimenter while participants had to memorize letters during a short retention interval. Moreover, a secondary task was introduced in some conditions to reduce the availability of attention. Experiment 2 replicated experiment 1 with the addition of a concurrent articulation to prevent the use of verbal rehearsal. The results showed that participants in the presence of the experimenter recalled fewer letters than participants who stayed alone in the cubicle, but only in experiment 2. These findings are the first evidence that social presence hinders attentional but not nonattentional maintenance in working memory. They have strong implications for understanding working memory and the impact of social presence, as well as important methodological implications.