Abstract
In visual search, the presence of a salient, yet task-irrelevant, distractor in the stimulus array interferes with target selection and slows-down performance. This is partly due to the unwanted shift of attention to the salient stimulus - the so-called attentional capture effect, which delays deployment of attention onto the target. Although automatic and unintentional, previous evidence indicated that attentional capture by a salient distractor is nonetheless modulated by cross-trial contingent history: The distractor cost is more robust when there is no distractor on the previous trial, compared to when there is one, perhaps implying dynamic engagement of proactive filtering mechanisms in the latter condition. Here we used transcranial magnetic stimulation (TMS) to shed light on the causal role of two crucial nodes of the ventral attention network, namely the Temporo-parietal Junction (TPJ) and Middle Frontal Gyrus (MFG), in the exogenous control of attention and its history-dependent modulation. Participants were required to locate a target arrow amongst non-target items and to discriminate the direction of the arrow while ignoring a task-irrelevant salient distractor, when present. Immediately after display onset, 10 Hz triple-pulse TMS was delivered either to TPJ or MFG on the right hemisphere. Compared to a suitable sham condition, results demonstrated that stimulation of right TPJ enhanced the cost associated with the distractor. Crucially, this effect was selectively observed when the preceding trial was a no-distractor trial. No significant effect was observed after MFG stimulation. These findings indicate that TMS of right TPJ exacerbates the interfering effect of a salient distractor, likely reflecting enhanced stimulus-driven control of attention. Since the effect was selectively obtained when the system was more susceptible to attentional capture (i.e., following a no-distractor trial), the evidence further demonstrates a causal role of TPJ in mediating the history-dependent modulation of attentional capture.