Introduction
In a neurophysiological study, Wannig et al. (2011) measured neuronal activity in primary visual cortex (area V1) of macaque monkeys and found evidence for an automatic spread of attention to objects outside of the attentional focus when they were grouped with an attended stimulus by Gestalt criteria. In particular, they reported an increase in the activity of neurons whose receptive field contained stimuli that were grouped with saccade target by one or several gestalt criteria (collinearity or similarity, their combination, or common fate). The goal of our study is to show whether this allocation of attention can be observed in humans, at a behavioral level.