The Time Course of Attentional Focusing

In four experiments, we investigated the time course of attentional focusing. Our main aims were to estimate the time necessary for focusing to take place and the time over which focal attention can be maintained. The use of a pre-cueing procedure allowed us to estimate the time necessary for focusing, excluding the time needed for orienting. The results of the ® rst three experiments showed that the focus of attention requires 33 ± 66 msec to adjust to an object in the visual ® eld, and that active focusing cannot be maintained beyond about 500 msec. In the fourth experiment, we also investigated if focusing was as e cient at the periphery as in the centre of the visual ® eld. The results showed that the time course of focusing is di€ erent in the periphery with respect to the centre, supporting the hypothesis of low e ciency of the attentional focus when it works outside the fovea.