Abstract
The ability to select and ignore specific objects improves considerably due to prior experience (attentional learning). However, such learning, in order to be adaptive, should depend on the more-or-less favourable outcomes of past attentional episodes. We have systematically explored this possibility by delivering monetary rewards to human observers performing attention-demanding tasks. In all experiments, participants were told that high and low rewards indexed optimal and sub-optimal performance, respectively, though reward amount was entirely pre-determined. Firstly, we demonstrated that rewards adjust the immediate consequences of actively ignoring a distracter, known as negative priming. Specifically, we found that negative priming is only obtained following high rewards, indicating that lingering inhibition is abolished by poor outcomes. Subsequently, we assessed whether rewards can also adjust attentional biases in the distant future. Here, observers were trained with a paradigm where, on each trial, they selected a target while ignoring a distracter, followed by differential reward. Importantly, the probability of a high vs. low reward varied for different objects. Participants were then tested days later in the absence of reward. We found that now the observers' ability to select and ignore specific objects strongly depended on the probability of high vs. low reward associated to a given object during training and also critically on whether the imbalance had been applied when the object was shown as target or distracter during training. These observations show that an observer's attentional biases towards specific objects strongly reflect the more-or-less favourable outcomes of past attentional processing of the same objects.