| Description |
Residual costs have been demonstrated in discrete task switching paradigms for decades. However, residual costs have recently been shown to last considerably longer than previously thought when intermittent multitasking is occurring. Three experiments aimed to replicate (Experiment 1) and manipulate residual costs in a controlled driving environment. Two theories were hypothesized to contribute to the residual cost formation, Task Set Inertia (TSI) and Situation Awareness Recovery (SAR). TSI was tested by manipulating the difficulty and complexity of a secondary task, with a more complex task believed to "linger" longer causing increased residual costs. SAR was tested by manipulating the complexity of the driving environment, with greater complexity believed to contribute to a greater amount of time to recover situation awareness. Reaction time, accuracy, and eye tracking were measured over time to assess the differential contribution of both theories to the residual costs. The results support both TSI and SAR as contributing to the creation of the residual costs, with the costs being found following tasks without loss of situation awareness (Experiment 2), and varying between different driving environment complexities (Experiment 3). The two most robust eye tracking measures, gaze time spent in regions of interest (ROIs) and standard deviation of horizontal dispersion revealed changes in visual scanning indicative of drivers actively reacquiring awareness of the driving environment following secondary task engagement. |
