Abstract
Previous research has shown that attention can be divided into two independent foci, although it can take up to 80 ms to do so (Jefferies & Witt, 2019). The factors that influence the rate of dividing attention, however, are not yet fully understood. In the present study we examined whether one factor – whether an individual is monolingual or bilingual – influences the rate at which attention can be divided. Bilingual individuals are known to disengage attention more rapidly than monolingual individuals (e.g., Mishra et al., 2012); consequently, monolingual individuals were expected to maintain attention in unitary form for longer and to divide attention more slowly than bilingual individuals. To test this, we compared the timecourse of dividing attention in individuals who were bilingual and in individuals who were monolingual. To assess the timecourse of divided attention, we employed a dual-stream Attentional Blink paradigm and two pairs of letter targets. One component of the AB, Lag-1 sparing, is known to occur only if the second target-pair appears within the focus of attention. By presenting the second target-pair at spatial locations either within the two streams or between the streams, we assessed whether attention was unitary or divided. By manipulating the stimulus-onset-asynchrony between the targets, we tracked changes to the spatial distribution of attention over time. The results showed clearly that bilingual individuals divide attention more rapidly than monolingual individuals. The current results not only identify a key factor that influences the timecourse of dividing attention, but further suggest that dividing attention, like the orienting of attention, is a three-stage process in which attention must be disengaged before its spatial distribution can be changed.