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Title: The impact of temporal stress and cognitive workload on prefrontal activation and technical performance in surgeons
Author: Modi, Hemel
ISNI:       0000 0004 7659 0510
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2019
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Surgeons face a plethora of stressors in the operating theatre which can increase mental demands, disrupt motor and cognitive performance, and potentially jeopardise patient safety. The prefrontal cortex (PFC) plays a crucial role in modulating workload-related performance due to its role in top-down processing. Data from outside medical practice suggests that PFC activity initially scales linearly with workload, but then attenuates at excessive workload levels. However, there is limited evidence shedding light on the impact of acute intraoperative stress on the operator cognition. The purpose of this thesis is to investigate brain behaviour in surgeons during stressful conditions and determine how the workload-activation-performance relationship is affected by expertise, resilience to stress and novel surgical instrumentation (e.g. robotic surgery). The first study reveals that senior trainees exhibit greater technical performance stability under time pressure, possibly due to sustained PFC activation and greater task engagement. In contrast, junior trainees demonstrate greater performance deterioration and relative loss of PFC activation. The second study demonstrates that stable performance under temporal stress is associated with typical activation responses in the lateral PFC, whereas performance decline under time pressure is associated with deactivation or 'inverse' responses. The third study builds on the preceding chapters with the addition of medical decision-making scenarios as an additional stressor. Senior trainees are able to maintain task engagement and attention when faced with a single intraoperative stressor, but struggle to recruit prefrontal regions when processing both temporal and cognitive loads simultaneously which may represent a breakdown of divided attention strategies. Conversely, more junior trainees are unable to maintain prefrontal engagement even when faced with a single stressor, yet concomitant temporal and cognitive demands prompts increased prefrontal recruitment, possibly reflecting resource allocation preferences. In order to delineate how surgical technologies modulate workload-induced changes in operator cognition, the final study shows that robotic platforms enable greater prefrontal recruitment and task engagement during stressful conditions compared with the laparoscopic approach. This thesis sheds light on how acute intraoperative stress affects cortical function by delineating the neural responses that may underpin stress-related performance decline in surgery. Brain imaging has potential as an objective method of assessing stress-coping ability in surgeons and may be used as an adjunct when determining whether a surgeon is ready for independent practice. Neuroimaging may also allow assessment of the impact of novel surgical technologies or training interventions to establish whether they have the desired effect on operator cognition.
Supervisor: Leff, Daniel ; Darzi, Ara Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral