Vermeulen, N. 1, 2 , Chang, B. 1 & Mermillod, M. 3
1 Université catholique de Louvain (UCL), Belgium
2 National Funds for Scientific Research (FRS-FNRS), Belgium
3 University of Clermont-Ferrand, France
It is well-known that attentional resource capacities are limited, though it was recently found that detecting a target can facilitate the encoding of a simultaneously presented background image, an effect called “Attentional Boost” (Swallow & Jiang, 2010). However, it is not clear whether this effect is due to the target status of the target stimulus (i.e. the status of being responded to), or to the rarity of the target stimulus. We investigated this issue in two experiments by manipulating the frequency of target and distractor stimuli. In an oddball task, half the participants pressed the spacebar in response to the rare stimulus (i.e., the target was rare and the distractors were frequent), while the other half pressed the spacebar in response to the frequent stimulus (i.e., the target was frequent and the distractor was rare). Results showed that the presence of rare stimuli increased the recognition rates of background stimuli, regardless of whether the rare stimuli were targets or distractors. These findings demonstrated that the attentional boost effect is caused by stimulus novelty/rarity, rather than target status.