This thesis examines the working memory (WM) function of authorised firearms officers (AFOs) after participation in a variety of simulated armed confrontations. In the UK, AFOs are required to operate and make decisions during situations in which there is a high degree of threat, novelty, time pressure, a large volume of perceptual information and a requirement to multi-task. A small amount of anecdotal evidence details the numerous perceptual distortions encountered by police officers in such situations. Whilst naturalistic decision making theories detail the cognitive heuristics employed by professionals who operate in comparable environments (e.g. fire fighters and military personnel), an investigation of the precise cognitive adaptations which occur during such demanding situations has not (to the knowledge of the researcher) been conducted. AFOs are required to use the conflict management model (CMM) to guide decision making; one of the main hypotheses in the present thesis is that the adequate use of the CMM requires Working Memory (WM) processing. As the multi-store model of WM is the accepted gold standard for behavioural experimentation; this was invoked as a template for the systematic examination of WM function in AFOs.
To explore these issues, the researcher attended a variety of tactical training packages involving AFOs. In total over 200 training days were attended, including theoretical inputs. Discussions with firearms officers and their trainers facilitated the development of studies and subsequent interpretation of results. A total of 75 AFOs participated in 9 studies conducted around highly immersive simulated armed confrontations. Which were designed by firearms trainers to test AFOs tactic completion and decision making. A variety of standardised measures of WM function were sourced and administered to AFOs at various time points in relation to a simulated armed confrontation. This provided a body of work with high replicability and ecological validity. A variety of physiological measures were also collected, the rationale for which was as a test to establish if the simulated armed confrontations placed the anticipated level of demand on the officers. These measures were also used to make tentative inferences concerning the relationship between cognitive adaptations and physiological arousal which is well documented in the literature.
The results suggest that the completion of tactics which are over learned (e.g. standard operating procedures) leads to a reduction in executive cognitive functioning whilst non-executive cognitive functioning simultaneously increases. It is reasonable to suggest that the available information processing capacity was devoted to following the standard operating procedure rather than making tactical decisions from scratch, hence the relative increase in non-executive functioning. The completion of novel and more complex tactics resulted in an increase in executive cognitive function whilst non-executive function decreased. It is also possible that the absence of experiential learning led to the allocation of information processing capacity to executive functioning in order to facilitate making novel tactical decisions in the absence of the ability to pattern match the cues from the environment.
The demand placed on AFOs during a simulated armed confrontation appeared to lead to a shift in cognitive function. An increase in the processing of visuo-spatial information was observed, at the cost of phonological processing. The literature suggests this may represent a shift from left hemispheric cortical function to right hemispheric and more posterior activity. Information from two sources and particularly from different modalities cannot be simultaneously processed and attended to. In situations of high demand a faster speed of information processing and increased attention focus is achieved through decrease in PFC function. Attention is directed to the perceptual cue(s) most likely to facilitate with the coping/removing of the source of threat.
It is suggested that these cognitive adaptations are defensive behaviours placing the officers in the optimum state to deal with the perceived threat. For example, the cognitive adaptations may reflect evolutionary responses to facilitate survival in situations of increased demand/threat. Hence these changes (even when decreases were observed) should not necessarily be viewed as deficits. Increases in physiological arousal demonstrated that the simulated armed confrontations placed increased demand on the AFOs resulting in a general adaptive response. Nevertheless, at all time points, in every test, performance was maintained at a relatively high level compared to control situations.
The simulated armed confrontations conducted during the tactical training of authorised firearms officers provided a rare platform to investigate defensive behaviours in humans. The applications of the findings are discussed in terms of police training/policy, inputs to theory and methodological progress. It is also argued that, as well as demonstrating that defensive adaptations in humans result in cognitive shifts, more generally, the current studies may provide a foundation for the ethological study of human defensive behaviour.