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.

Noticing spiders on the left: Evidence on attentional bias and spider fear in the inattentional blindness paradigm.

Attentional biases in anxiety disorders have been assessed primarily using three types of experiment: the emotional Stroop task, the probe-detection task, and variations of the visual search task. It is proposed that the inattentional blindness procedure has the ability to overcome limitations of these paradigms in regard to identifying the components of attentional bias. Three experiments examined attentional responding to spider images in individuals with low and moderate to high spider fear. The results demonstrate that spider fear causes a bias in the engage component of visual attention and this is specific to stimuli presented in the left visual field (i.e., to the right hemisphere). The implications of the results are discussed and recommendations for future research are made.

Hemispheric asymmetries in categorical perception of orientation in infants and adults.

Orientation CP is the faster or more accurate discrimination of two orientations from different categories (e.g., oblique1 and vertical1) compared to two orientations from the same category (e.g., oblique1 and oblique2), even when the degree of difference is equated across conditions. Here, we assess whether there are hemispheric asymmetries in this effect for adults and 5-month-old infants. Experiment 1 identified the location of the vertical-oblique category boundary. Experiment 2, using a visual search task with oriented lines found that adult search was more accurate when the target and distractors were from different orientation categories, compared to targets and distractors of an equivalent physical difference taken from the same category. This effect was stronger for targets lateralized to the left visual field (LVF) than the right visual field (RVF), indicating a right hemisphere (RH) bias in adult orientation CP. Experiment 3, replicated the RH bias using different stimuli and also investigated the impact of visual and verbal interference on the category effect. Experiment 4, using the same visual search task, found that infant search was also faster when the target and distractors were from different orientation categories than the same, yet this category effect was stronger for RVF than LVF lateralized targets, indicating a LH bias in orientation CP at 5 months. These findings are contrasted to equivalent studies on the lateralization of color CP (e.g., Gilbert, Regier, Kay, & Ivry, 2005). The implications for theories on the contribution of the left and right hemispheres of the infant and adult brain to categorical computations are discussed.