Assessing cross-modal interference in the detection response task

The detection response task (DRT) is a measure of workload that can assess the cognitive demands of real-world multitasking. It can be configured to present simple stimuli of several modalities, including auditory and visual signals. However, the concurrent presentation of the DRT stimuli alongside another task could cause dual-task interference, and the extent of this interference could be different based on the DRT's configuration. It is necessary to consider the characteristics of the DRT stimulus, such as modality, to identify a minimally intrusive stimulus. Fifty participants completed a computer-based one-dimensional tracking task alongside a DRT. The DRT's stimuli varied in their modality (visual/auditory), while the tracking task varied in its workload demand (low/high). DRT performance was modelled using a shifted-Wald model, while the tracking task was assessed using systems factorial technology (SFT), a non-parametric methodology capable of capturing a cognitive system's workload capacity. To allow the latter's use, we developed a method of transforming continuous tracking data into a discrete form akin to response times. Analysis of DRT data found little evidence that the DRT's modality affected processing efficiency, while SFT analysis found limited-capacity processing on the tracking task across both DRT modalities. These findings suggest DRT modality had little effect on the level of interference between the two tasks.