Abstract
Previous studies have shown that the maintenance of an object in visual working memory (VWM) automatically biases spatial attention toward the location of an object with matching features. Oculomotor theories of attention argue this bias occurs because of competition between the motor plan for the saccade endpoint and location of object held in VWM. Here we looked at the interaction between VWM and motor control by measuring attention when the goal of a saccadic eye-movement is congruent or incongruent with location of an object sharing properties with the content of VWM. In the current study, participants had to perform a saccade towards a specified location (the Saccade Target, ST) and made a discrimination decision (the Discrimination Target, DT). In the experimental condition, they had to retain a colour in VWM for the whole duration of the trial (the Memory Target; MT). There were four different conditions: 1) MT congruent with both ST and DT, 2) MT congruent with DT but incongruent with ST, 3) MT congruent with ST but incongruent with DT, 4) MT incongruent with both ST and DT. In 1/3 or the trial the MT colour was absent from the stimulus array. As expected, pre-saccadic attentional facilitation was greatest when the content of the VWM, the direction of the saccade and the DT location were all congruent, and abolished when ST, DT and MT were at different locations. Critically, when the ST and DT were in the same location but the MT at a different location pre-saccadic attentional facilitation was significantly reduced, suggesting competition between the saccade goal and the MT. Our results are consistent with the idea that automatic guidance of attention by the content of VWM can be operationalised as a competition between different saccade goals in the oculomotor system.
Acknowledgement: ESRC grant (ES/N018842/1)