| dc.description.abstract | The interaction between voluntary attentional control and stimulus-driven attentional control may result in the efficiency of the deployment of attention.. Nontarget items that are salient and match for the defining feature of the target can capture attention effectively. This phenomenon is so-called contingent attentional capture because the capture is contingent on that the features of the nontarget need to be consistent with the attentional set of the task. In the present study, we used contingent attentional capture task and repetitive transcranial magnetic stimulation (rTMS) to investigate the neural mechanism of attentional control.
Previous studies showed that two neural networks are involved in two attentional control systems. The dorsal frontoparietal network generates and maintains voluntary control; the ventral frontoparietal network is modulated by attentional shifts to behaviorally relevant stimuli. We choose right frontal eye fields (rFEF) and right temporoparietal junction (rTPJ) as the representative sites of dorsal and ventral networks, respectively. In the first two TMS experiments, rTMS (10Hz, 200 ms) was applied over rFEF either 200 ms before, simultaneously with, or 200 ms after the onset of the visual search array. When rFEF and rTPJ were stimulated before the onset of search array, the overall reaction time was decreased. However, when rFEF were stimulated 200ms after the onset of the stimuli, the reaction time was increased. The results suggested that rFEF may play a causal role in deployment of attention. However, the two experiments did not observe selective modulation of TMS on contingent attentional capture. In the third set of TMS experiments, we applied some modifications to test the attentional shift caused by contingent capture and the results of compatibility effects for the verification that abrupt onset caused attentional shifting into the stage of motor preparation. The results also shown rTMS applied on the both regions would reduce the reaction time cost of incompatible onset regardless of any onset types.
The present results demonstrate the causal relationship between rFEF and visual attention, however, several experiments derived from the current study are needed to be carried out for elucidating the functional roles of rTPJ and rFEF in the control of the contingent attentional capture. | en_US |