Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

Cognitive resource theory is a proposed explanation for people's limited ability to perform multiple tasks simultaneously. Reallocation of a restricted supply of cognitive resources to two or more tasks may be detrimental to performance on one or both tasks. Many professionals in high-risk fields, such as those engaged in firefighting, military, and search and rescue missions, face simultaneous mental and physical demands, yet little is known about the resources required to move over the natural terrain these operators may encounter. In the present research, we investigated whether interference was found between outdoor running and a word recall task. As hypothesized, a reduction in word recall was observed in the dual task compared to a recall-alone task; however, the distance run was not significantly different between the dual task and the run-alone task. Subjective reports of workload, task focus, and being "spent" (measures calculated from responses on a questionnaire) were greatest in the dual task. These results support the cognitive resource theory and have important theoretical and practical implications. Further research is required to better understand the type and extent of cognitive resources required by such physical tasks and the potential interference with simultaneous mental tasks.

Research continues to provide evidence that people are poor multi-taskers. Cognitive resource theory is a common explanation for the inability to efficiently perform multiple tasks at the same time. This theory proposes that one's limited supply of cognitive resources can be utilized faster than it is replenished, which results in a performance decline, particularly when these limited resources must be allocated among multiple tasks. Researchers have proposed both domain-specific, for example, spatial versus verbal processing resources, and domain general cognitive resources. In the present research, we investigated whether a spatial puzzle task performed simultaneously with a verbal recall task would impair performance in either task or both tasks, compared to performance on the tasks individually. As hypothesized, a reduction in word recall was found when dual-tasking, though performance on the puzzle task did not significantly differ between the single- and dual-task conditions. This is consistent, in part, with both a general resource theory and a Multiple Resource Theory, but further work is required to better understand the cognitive processing system. The employment of the recall task in the dual-task paradigm with a variety of secondary tasks will help to continue mapping out the specificity (or lack thereof) of cognitive resources utilized in various mental and physical tasks.

Cognitive resource limitations can impair one's ability to multitask. Previous research has shown that climbing is a particularly demanding task, and does not neatly fit into existing cognitive resource models. Climbing is a task relevant to firefighting and search and rescue, and operators often must also handle communication and navigation tasks in tandem. We present the results of a study where a naturalistic narrative memory task was paired with a climbing traverse. As hypothesized, both climbing and memory performance significantly declined in the dualcompared to each single-task condition. The specific cognitive demands of climbing should be explored further using non-verbal secondary tasks, to determine whether an executive resource bottleneck, verbal resource demand, or something else entirely can better explain the dual-task interference. A more thorough understanding of the mental demand in concurrent operational tasks can be used to tailor the modality and timing or diversion of certain tasks for minimal interference.

Objective: Two verbal tasks were utilized in a dual-task paradigm to explore performance theories and prior dual-tasking results. Background: Both the decline in vigilance performance over time, or vigilance decrement, and limited dual-tasking ability may be explained by limited mental resources. Resource theorists would recommend removing task demands to avoid cognitive overload, while mindlessness theorists may recommend adding engaging task demands to prevent boredom. Prior research demonstrated interference between a verbal free recall and semantic vigilance task, but exploring tasks with greater ecological validity is necessary. Method: A narrative memory task and semantic vigilance task were performed individually and simultaneously. Relative performance impairments were compared to a previous dual-task pairing. Results: The semantic vigilance task caused performance degradation to the narrative memory task and vice versa. A vigilance decrement was not observed, and the interference was to a lesser extent than when the semantic vigilance task was paired with a free recall task. Conclusion: Resource theory was supported, though passive learning effects during a semantic vigilance task with novel stimuli may prevent a vigilance decrement. The interference was less than that of a previous similar dual-task pairing, but even tasks as routine as listening to a conversation or story can impair other task performance. Application: A better understanding of resource theory and dual-task performance outcomes can help inform feasible task loads and improve efficiency and safety of operators in high-risk and other professions.