Contextual cueing during lethal force training: How target design and repetition can alter threat assessments.

Lethal force training requires individuals to make threat assessments, which involves holistic scenario processing to identify potential threats. Photorealistic targets can make threat/non-threat judgments substantially more genuine and challenging compared to simple cardboard or silhouette targets. Unfortunately, repeated target use also brings unintended consequences that could invalidate threat assessment processes conducted during training. Contextually rich or unique targets could be implicitly memorable in a way that allows observers to recall weapon locations rather than forcing observers to conduct a naturalistic assessment. Experiment 1 demonstrated robust contextual cueing effects in a well-established shoot/don't-shoot stimulus set, and Experiment 2 extended this finding from complex scene stimuli to simple actor-only stimuli. Experiment 3 demonstrated that these effects also occurred among trained professionals using rifles rather than computer-based tasks. Taken together, these findings demonstrate the potential for uncontrolled target repetition to alter the fundamental processes of threat assessment during lethal force training.

How speed impacts threat assessment in lethal force decisions.

Despite the importance of being both fast and accurate in lethal force decisions, there is little empirical evidence to identify how speed impacts threat-related decisions and perception. Two experiments used speeded and unspeeded manipulations to determine how the speed imperative impacted threat assessments. Experiment 1 used drift diffusion modeling to quantify decision parameters, including rate of information processing, decision threshold, bias, and non-decisional processes. Speeded conditions reduced the information threshold needed to make decisions and shortened non-decisional processes, yet this manipulation had no impact on the rate of information processing or starting bias. Experiment 2 explored perceptual differences in threat assessment. Participants confidently made threat assessments despite only 30 ms exposure to stimuli with little impact on their subjective threat ratings based on exposure duration. Taken together, these results document the influence of speed on decision-making parameters of threat assessments while demonstrating little impact on threat perception.

A new look at memory retention and forgetting.

The forgetting curve is one of the most well known and established findings in memory research. Knowing the pattern of memory change over time can provide insight into underlying cognitive mechanisms. The default understanding is that forgetting follows a continuous, negatively accelerating function, such as a power function. We show that this understanding is incorrect. We first consider whether forgetting rates vary across different intervals of time reported in the literature. We found that there were different patterns of forgetting across different time periods. Next, we consider evidence that complex memories, such as those derived from event cognition, show different patterns, such as linear forgetting. Based on these findings, we argue that forgetting cannot be adequately explained by a single continuous function. As an alternative, we propose a Memory Phases Framework, through which the progress of memory can be divided into phases that parallel changes associated with neurological memory consolidation. These phases include (a) Working Memory (WM) during the first minute of retention, (b) Early Long-Term Memory (e-LTM) during the 12 hr following encoding, (c) a period of Transitional Long-Term Memory (t-LTM) during the following week or so, and (d) Long-Lasting Memory (LLM) memory beyond this. These findings are of significance for any field of study where being able to predict retention and forgetting is important, such as training, eyewitness memory, or clinical treatment. They are also important for evaluating behavioral or neuroscientific manipulations targeting memories over longer periods of time when different processes may be involved. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The role of inhibitory control in shoot/don't-shoot decisions.

Previous work has demonstrated a link between cognitive abilities, specifically inhibitory control and lethal force decision-making performance. However, many previously used approaches to simulating shoot/don't shoot scenarios have lacked ecological validity. There is a need to investigate how inhibitory control impacts shoot/don't decisions using realistic simulations to better translate the findings to military and law enforcement settings. This study used multiple cognitive control tasks incorporating discrete judgements in go/no-go and stop signal tasks as well as subjective judgements in go/no-go tasks with both colour stimuli and emotional faces. These combined tasks provided a comprehensive evaluation of inhibitory control abilities. To ensure ecological validity in shooting performance, existing military training scenarios incorporated realistic weaponry and aiming behaviours across different shoot/don't-shoot simulations. The inhibitory control battery identified five principal components from the various tasks, including: stopping ability, response speed, emotion detection, colour detection, and emotional biases. These principal inhibitory control components were entered into hierarchical linear regressions with the dependent variables of unintended casualties inflicted and lethal rounds fired, respectively. Stopping ability better predicted the likelihood of inflicting an unintended casualty, whereas response speed better predicted the number of lethal rounds fired. These regression models included baseline metrics of marksmanship and shots fired, which supports a role for inhibitory control above and beyond basic shooting abilities or strategy. These collective findings provide mechanistic support for the relationship between inhibitory control and errors in shoot/don't-shoot decision-making while using realistic military training scenarios.

When the response does not match the threat: The relationship between threat assessment and behavioural response in ambiguous lethal force decision-making.

Deciding when to use lethal force inherently depends on assessing threat, a process that itself incorporates numerous perceptual factors. This study assessed this relationship between perception-based threat assessment and behaviour-based threat response. Specifically, participants completed multiple tasks designed to elicit either a threat rating (e.g., perception-informed threat assessment) or a binary behavioural response (e.g., shoot/don't-shoot). Actor posture and weapon presence significantly affected the threat assessment, which was an extremely powerful omnibus predictor of threat response. However, for ambiguous threat stimuli, perceived threat became a poor predictor for threat response relative to the omnibus test. Participants appeared to adopt additional rules to inform behaviour independent of the threat assessment when faced with an ambiguous situation. These results demonstrate an intriguing disparity between subjective threat assessment and the behavioural response to use force that does not apply well to ambiguous cases or adequately explain errors in lethal force decisions.

Measuring Lethal Force Performance in the Lab: The Effects of Simulator Realism and Participant Experience.

OBJECTIVE: The goal of the current study was to compare two types of shooting simulators to determine which is best suited for assessing different aspects of lethal force performance. BACKGROUND: Military and law enforcement personnel are often required to make decisions regarding the use of lethal force. A critical goal of both training and research endeavors surrounding lethal force is to find ways to simulate lethal force encounters to better understand behavior in those scenarios. METHOD: Participants of varying degrees of experience completed both marksmanship and shoot/don't shoot scenarios on both a video game and a military-grade shooting simulator. Using signal detection theory, we assessed sensitivity as a measure of lethal force performance overall. We used hit rate to assess shooting accuracy and false alarm rate to assess decision making. RESULTS: Results demonstrated that performance was correlated across simulators. Results supported the notion that shooting accuracy and decision making are independent components of performance. Individuals with firearms expertise outperformed novices on the military-grade simulator, but only with respect to shooting accuracy, not unintended casualties. Individuals with video game experience outperformed novices in the video game simulator, but again only on shooting accuracy. CONCLUSION: Experience played a crucial role in the assessment of shooting accuracy on a given simulator platform; decision-making performance remained unaffected by experience level or type of simulator. APPLICATION: We recommend that in expert populations or when assessing shooting accuracy, a military-grade shooting simulator be used. However, with a novice population and/or when interested in decision making in lethal force, a video game simulator is appropriate.

Postural Instability and Seasickness in a Motion-Based Shooting Simulation.

BACKGROUND: Motion sickness is a problem for many; however, it is especially pressing for military personnel who need to operate in life and death environments. The current study investigated the underlying cause of motion sickness by testing postural instability theory.METHODS: Subjects experienced realistic motion profiles while performing a virtual reality shooting task and reporting any motion sickness symptoms. Postural instability was manipulated within 20 subjects across 2 conditions. In one condition, subjects could readily adapt their posture to the motion profile by adjusting their feet on the platform (Free), and in the other condition, their feet were fixed in place on the moving platform (Fixed). This Free condition decreased postural instability by allowing adjustment, while the Fixed condition increased postural instability by restricting adjustment. The same subjects completed both conditions to control for individual differences in motion sickness susceptibility.RESULTS: Overall, motion sickness was mild as measured by SSQ (M 14.41, Free; M 18.89, Fixed), and no statistically significant differences were observed between the conditions. Performance on the shooting task was reduced in accuracy by approximately 40%, although this result did not differ between conditions.DISCUSSION: The results do not support postural instability as a contributing factor in motion sickness symptomology. They also demonstrate the importance of accounting for motion when conducting training.Pettijohn KA, Pistone DV, Warner AL, Roush GJ, Biggs AT. Postural instability and seasickness in a motion-based shooting simulation. Aerosp Med Hum Perform. 2020; 91(9):703709.

Virtual and augmented reality in a simulated naval engagement: Preliminary comparisons of simulator sickness and human performance.

The aim of this study was to compare simulator sickness symptoms while participants wore either a virtual reality (VR) or augmented reality (AR) headset. A secondary aim involved comparing how physical motion affects symptoms. During a simulation, participants wore VR and AR headsets while standing on a motion platform and firing at hostile ships under three motion conditions: No Physical Motion; Synchronous Motion, in which the physical and displayed motion were coupled; and Asynchronous Motion, in which the physical motion did not match the display. Symptoms increased over time but were not different with respect to headset or motion. The VR condition had higher accuracy and faster response time to the commence fire instruction. Further research is necessary to determine if this holds under more extreme motion. The use of VR or AR headsets for training under gentle motion conditions is practicable and should be permissible under normal conditions during deployment.

Postural Instability and Simulator Seasickness.

BACKGROUND: Motion sickness is a serious issue for many individuals, but the problem is particularly important among military personnel who may regularly experience unusual or extreme motion profiles as a part of their duties. As such, it is important to understand the underlying mechanisms that contribute to motion sickness, which in turn can lead to new and more effective countermeasures. The current study investigated causal etiology by examining the predictions of postural instability theory. Subjects experienced multiple motion profiles while reporting their sickness symptoms. METHODS: Postural instability was directly manipulated by including both an active and passive condition. In the active condition, subjects could actively adapt their posture to the motion profile. In the passive condition, subjects had their feet affixed in place and could not effectively adapt their posture to the motion profiles. Subjects completed both conditions to control for individual differences in motion sickness susceptibility. RESULTS: Active condition subjects had greater postural stability as measured by sample entropy (M = 0.179 Active, M = 0.136 Passive), and sickness symptoms increased with time. Both results provide a methodological check against our manipulation. However, there were no differences in symptoms between active or passive conditions as measured by the simulator sickness questionnaire (M = 16.56 and M = 18.25, respectively), and no relationship between our measure of postural instability and symptomology. DISCUSSION: These results do not support postural instability as the primary causal factor in motion sickness; however, more research is needed to elucidate the mechanisms of motion sickness etiology.Pettijohn KA, Geyer D, Gomez J, Becker WJ, Biggs AT. Postural instability and simulator seasickness. Aerosp Med Hum Perform. 2018; 89(7):634-641.

Walking through doorways causes forgetting: recall.

The aim of the current study was to explore how the location updating effect is affected when people are tested using recall rather than recognition, which is what has been done in prior work. Differences in the memory processes involved with these two tasks lead to predictions for two different patterns of data. In Experiment 1, memory was tested by having participants recall the single object they were carrying or had just put down, whereas in Experiment 2, people sometimes needed to recall both objects. It was found that, unlike recognition test performance, a similar location updating effect was found for both Associated (what was currently being carried) and Dissociated (what was recently set down) objects. Moreover, when both objects were correctly recalled, there was a bias to remember them in the order that they were encountered. Finally, if only one object was correctly recalled, it was the Associated object that was currently being carried. Overall, these results are consistent with the Event Horizon Model of event cognition.

Narrative event boundaries, reading times, and expectation.

During text comprehension, readers create mental representations of the described events, called situation models. When new information is encountered, these models must be updated or new ones created. Consistent with the event indexing model, previous studies have shown that when readers encounter an event shift, reading times often increase. However, such increases are not consistently observed. This paper addresses this inconsistency by examining the extent to which reading-time differences observed at event shifts reflect an unexpectedness in the narrative rather than processes involved in model updating. In two reassessments of prior work, event shifts known to increase reading time were rated as less expected, and expectedness ratings significantly predicted reading time. In three new experiments, participants read stories in which an event shift was or was not foreshadowed, thereby influencing expectedness of the shift. Experiment 1 revealed that readers do not expect event shifts, but foreshadowing eliminates this. Experiment 2 showed that foreshadowing does not affect identification of event shifts. Finally, Experiment 3 found that, although reading times increased when an event shift was not foreshadowed, they were not different from controls when it was. Moreover, responses to memory probes were slower following an event shift regardless of foreshadowing, suggesting that situation model updating had taken place. Overall, the results support the idea that previously observed reading time increases at event shifts reflect, at least in part, a reader's unexpected encounter with a shift rather than an increase in processing effort required to update a situation model.

Event boundaries and memory improvement.

The structure of events can influence later memory for information that is embedded in them, with evidence indicating that event boundaries can both impair and enhance memory. The current study explored whether the presence of event boundaries during encoding can structure information to improve memory. In Experiment 1, memory for a list of words was tested in which event structure was manipulated by having participants walk through a doorway, or not, halfway through the word list. In Experiment 2, memory for lists of words was tested in which event structure was manipulated using computer windows. Finally, in Experiments 3 and 4, event structure was manipulated by having event shifts described in narrative texts. The consistent finding across all of these methods and materials was that memory was better when the information was distributed across two events rather than combined into a single event. Moreover, Experiment 4 demonstrated that increasing the number of event boundaries from one to two increased the memory benefit. These results are interpreted in the context of the Event Horizon Model of event cognition.

Walking through doorways causes forgetting: Event structure or updating disruption?

According to event cognition theory, people segment experience into separate event models. One consequence of this segmentation is that when people transport objects from one location to another, memory is worse than if people move across a large location. In two experiments participants navigated through a virtual environment, and recognition memory was tested in either the presence or the absence of a location shift for objects that were recently interacted with (i.e., just picked up or set down). Of particular concern here is whether this location updating effect is due to (a) differences in retention intervals as a result of the navigation process, (b) a temporary disruption in cognitive processing that may occur as a result of the updating processes, or (c) a need to manage multiple event models, as has been suggested in prior research. Experiment 1 explored whether retention interval is driving this effect by recording travel times from the acquisition of an object and the probe time. The results revealed that travel times were similar, thereby rejecting a retention interval explanation. Experiment 2 explored whether a temporary disruption in processing is producing the effect by introducing a 3-second delay prior to the presentation of a memory probe. The pattern of results was not affected by adding a delay, thereby rejecting a temporary disruption account. These results are interpreted in the context of the event horizon model, which suggests that when there are multiple event models that contain common elements there is interference at retrieval, which compromises performance.

Walking through doorways causes forgetting: Younger and older adults.

Previous research on event cognition has found that walking through doorways can cause forgetting. The explanation for this finding is that there is a competition between event models, producing interference, and depressing performance. The current study explored the degree to which this might be affected by the natural aging process. This is of interest because there is some evidence that older adults have trouble coordinating sources of interference, which is what is thought to underlie this effect. This would suggest that older adults should do worse on this task. Alternatively, there is also evidence that older adults are typically not disrupted at the event level of processing per se. This would suggest that older adults should perform similarly to younger adults on this task. In the study reported here, younger and older participants navigated through a virtual environment, and memory was tested with probes either before or after a shift and for objects that were associated with the participant (i.e., just picked up). In general, both younger and older adults had memory disrupted after walking through a doorway. Importantly, the magnitude of this disruption was similar in the 2 age groups. This is consistent with the idea that processing at the event level is relatively unaffected by the natural aging process. (PsycINFO Database Record