The existing literature suggests a critical role for both the right intraparietal sulcus (IPS) and the right temporo-parietal junction (TPJ) in our ability to attend to multiple simultaneously-presented lateralised targets (multi-target attention), and the failure of this ability in extinction patients. Currently, however, the precise role of each of these areas in multi-target attention is unclear. In this study, we combined the theory of visual attention (TVA) with functional magnetic resonance imaging (fMRI) guided continuous theta burst stimulation (cTBS) in neurologically healthy subjects to directly investigate the role of the right IPS and TPJ in multi-target attention. Our results show that cTBS at an area of the right IPS associated with multi-target attention elicits a reduction of visual short-term memory capacity. This suggests that the right IPS is associated with a general capacity-limited encoding mechanism that is engaged regardless of whether targets have to be attended or remembered. Curiously, however, cTBS to the right IPS failed to elicit extinction-like behaviour in our study, supporting previous suggestions that different areas of the right IPS may provide different contributions to multi-target attention. CTBS to the right TPJ failed to induce a change in either TVA parameters or extinction-like behaviour.
Explaining semantic short-term memory deficits: Evidence for the critical role of semantic control
