|Authors||Broeker, J., Fandakova, Y., Khrosravani, N., Kiesel, A., Kubik, V., Kübler, S., Manzey, D., Monno, I., Raab, M. and Schubert, T.|
Little more than a decade ago, a study by Watson and Strayer (2010) brought forward the concept of
supertaskers, because 5 of the 200 participants tested had the remarkable ability to perform a driving task and an operation span task without any costs. This outcome, which accentuates the potential impact of individual differences on multitasking, caused a stir in dual-task research by challenging previous assumptions about the cognitive architecture and the robust empirical evidence about limited cognitive resources and imperfect time-sharing (Kahneman, 1973; Tombu & Jolicœur, 2003; Wickens, 2002). Adhering to the common assumption that multiple tasks cannot be performed without interference or costs, dual-task research had primarily focused on discovering and explaining the mechanisms underlying limitations in information processing (Meyer & Kieras, 1997; Wickens, 1980). As a result, researchers have been very successful in developing distinguished paradigms and establishing differentiated theories on dual-task and task-switching costs valid across multiple studies on human participants (Koch et al., 2018). It has been suggested that this work is best organized according to three research perspectives, which differ in their focus on cognitive structure, flexibility, and plasticity (for the full review see Koch et al., 2018). In their review, Koch et al. mention that there might be some relations between the three perspectives and that they should be seen as complementary rather than competitive in the sense that they refer “either to the current status of the cognitive system (structure, flexibility) or its dynamic change (plasticity)” (p. 558). However, the review remains short on explicitly describing or explaining the intersections between the three perspectives. The overall goal of this theoretical note is to show that the explicit consideration of individual differences is one possible way to elaborate in more detail on how and why the perspectives complement each other, that is, why the consideration of individual differences in one perspective can enhance the understanding of the other perspective. Whereas most established work on multitasking has been derived from group means, we posit that too little emphasis has been put on variability between and within participants (see also the requirement for nomothetic instead of Aristotelian view; e.g., Hommel & Colzato, 2017). To remedy this state, we will first define structure, flexibility and plasticity and describe what constitutes individual differences in these three perspectives. We will then outline selected empirical results on the intersections, without claiming to be exhaustive, and raise possible future research questions and directions.