Situation awareness and working memory: An integration of an applied concept with a fundamental cognitive process

This dissertation explored the relation between the applied concept of situation awareness (SA) and the basic cognitive mechanism of working memory (WM). SA is an important concept in applied research. It captures how operators perceive, comprehend and anticipate events in dynamic environments. There is substantial evidence both in basic and applied research to suggest that WM might be the cognitive mechanism necessary to support such dynamic comprehension. However, the potential relation between SA and WM is not well articulated. This lack of articulated relation between the two concepts is largely due to how researchers have conceptualized SA. Rather than thinking about SA in terms of processing of information by the underlying cognitive mechanisms, SA is commonly thought of as conscious comprehension that is separate from the underlying processes. The role of WM is therefore of little interest to the study of SA. Alternatively, the existing theoretical frameworks are too vague to fully explain the potential link between SA and WM.; It was hypothesized in this dissertation that SA depends on maintaining and processing information in the different WM systems. An existing WM model was used to establish a conceptual link between the two concepts. The role of WM in supporting SA was then tested empirically. A series of four experiments was conducted using a dual-task paradigm in which tracking tasks were combined with different WM load tasks. In experiment 1 and 2 participants tracked a moving object against a dynamic background. In experiment 3 participants had to periodically predict or search for the tracked object in addition to tracking it. In experiment 4 participants drove in a driving simulator. Their task was to maintain a central lane position (lateral tracking) and maintain SA for information around the vehicle. Simultaneously to the primary task, participants performed one of four load tasks. Each load task was designed to tap into the different WM systems. In all four experiments, the results provided support for the hypothesis that WM plays an active role in maintaining SA in a dynamic environment. A unique contribution of this research was to show that maintaining SA in a dynamic environment involves selectively the verbal and the spatial WM systems and central executive control. For example, in experiment 4 maintaining SA of surrounding cars required the spatial system for cars in front of the driver and the verbal system for cars in back of the driver. The implication of the results for SA theory and research is explored.