Is Semantic Vigilance Impaired by Narrative Memory Demands? Theory and Applications.

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.

Memory impairment during a climbing traverse: implications for search and rescue climbing.

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 dual-compared 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.

Quantitative Analysis of Situation Awareness (QASA): modelling and measuring situation awareness using signal detection theory.

This paper presents a model of situation awareness (SA) that emphasises that SA is necessarily built using a subset of available information. A technique (Quantitative Analysis of Situation Awareness - QASA), based around signal detection theory, has been developed from this model that provides separate measures of actual SA (ASA) and perceived SA (PSA), together with a feature unique to QASA, a measure of bias (information acceptance). These measures allow the exploration of the relationship between actual SA, perceived SA and information acceptance. QASA can also be used for the measurement of dynamic ASA, PSA and bias. Example studies are presented and full details of the implementation of the QASA technique are provided. Practitioner Summary: This paper presents a new model of situation awareness (SA) together with an associated tool (Quantitative Analysis of Situation Awareness - QASA) that employs signal detection theory to measure several aspects of SA, including actual and perceived SA and information acceptance. Full details are given of the implementation of the tool.

Mapping brain activity during loss of situation awareness: an EEG investigation of a basis for top-down influence on perception.

OBJECTIVE: The objective was to map brain activity during early intervals in loss of situation awareness (SA) to examine any co-activity in visual and high-order regions, reflecting grounds for top-down influences on Level I SA. BACKGROUND: Behavioral and neuroscience evidence indicates that high-order brain areas can engage before perception is complete. Inappropriate top-down messages may distort perception during loss of SA. Evidence of co-activity of perceptual and high-order regions would not confirm such influence but may reflect a basis for it. METHOD: SA and bias were measured using Quantitative Analysis of Situation Awareness and brain activity recorded with 128-channel EEG (electroencephalography) during loss of SA. One task (15 participants) required identification of a target pattern, and another task (10 participants) identification of "threat" in urban scenes. In both, the target was changed without warning, enforcing loss of SA. Key regions of brain activity were identified using source localization with standardized low-resolution electrical tomography (sLORETA) 150 to 160 ms post-stimulus onset in both tasks and also 100 to 110 ms in the second task. RESULTS: In both tasks, there was significant loss of SA and bias shift (p < .02), associated at both 150- and 100-ms intervals with co-activity of visual regions and prefrontal, anterior cingulate and parietal regions linked to cognition under uncertainty. CONCLUSION: There was early co-activity in high- order and visual perception regions that may provide a basis for top-down influence on perception. APPLICATION: Co-activity in high- and low-order brain regions may explain either beneficial or disruptive top-down influence on perception affecting Level I SA in real-world operations.