Differential contributions of the intraparietal sulcus and the inferior parietal lobe to attentional blink: evidence from transcranial magnetic stimulation.

When two targets (T1 and T2) are to be identified in rapid serial visual presentation, the response to T1 induces impairment of T2 report if T2 appears within 500 msec after T1 (attentional blink: AB). AB is thought to reflect temporal limitations of attention which affect target perception. Recent research suggests that the intraparietal sulcus (IPS) contributes to an attentional set associated with task goals, whereas the inferior parietal lobe (IPL) is associated with the disengagement and reorienting of attention to a relevant stimulus presented outside the current focus of attention. We investigated respective involvement of the IPS and the IPL in AB using transcranial magnetic stimulation (TMS). The results of Experiment 1 showed that the magnitude of AB deficit decreased TMS disrupted activity of the IPS after T1 onset. In addition, an increased AB deficit occurred when TMS was delivered over the IPS or IPL after T2 onset. In Experiment 2, where participants were instructed to ignore T1, they showed an AB-like T2 deficit only when TMS was delivered to the IPS after a T2 onset. Findings are discussed in terms of hypotheses about the respective roles of the IPS, in realizing an attentional set, and the IPL, in contributing to a disengagement of attention (from T1 to T2) during an AB period.