Understanding The Role of Cognitive Load In Paramedical Contexts: A Systematic Review.

Objectives: Cognitive load refers to the working memory resources required during a task. When the load is too high or too low this has implications for an individual's task performance. In the context of paramedicine and emergency medical services (EMS) broadly, high cognitive load could potentially put patient and personnel safety at risk. This systematic review aimed to determine the current understanding of the role of cognitive load in paramedical contexts.Methods: To do this, five databases were searched (Elsevier Embase, ProQuest Psychology, CINAHL, Ovid Medline, and Ovid PsychINFO) using synonyms of cognitive load and paramedical contexts. Included articles were full text, peer reviewed empirical research, with a focus on cognitive load and EMS work. Two reviewers screened titles, abstracts, and full text using a traffic light system against the inclusion and exclusion criteria. The quality of evidence was assessed using the GRADE framework. This study was registered on PROSPERO (CRD42022384246). No funding was received for this research.Results: The searches identified 73 unique articles and after title/abstract and full text screening, 25 articles were included in the final review. Synthesis of the research revealed 10 categories of findings in the area. These are clinical performance, cognitive processes, emotional responses, physical expenditure, physiological responses, equipment and ergonomics, expertise and experience, multiple loads, cognitive load measures, and task complexity.Conclusions: From these findings it was determined that there is agreement in terms of what factors influence cognitive load in paramedical contexts, such as cognitive processes, task complexity, physical expenditure, level of experience, multiple types of loads, and the use of equipment. Cognitive load influences clinical task performance and has a bi-directional relationship with emotion. However, the literature is mixed regarding physiological responses to cognitive load, and how they are best measured. These findings highlight potential intervention points where cognitive load can be managed or reduced to improve working conditions for EMS clinicians and safety for their patients.

The saccadic flow baseline: Accounting for image-independent biases in fixation behavior.

Much effort has been made to explain eye guidance during natural scene viewing. However, a substantial component of fixation placement appears to be a set of consistent biases in eye movement behavior. We introduce the concept of saccadic flow, a generalization of the central bias that describes the image-independent conditional probability of making a saccade to (xi+1, yi+1), given a fixation at (xi, yi). We suggest that saccadic flow can be a useful prior when carrying out analyses of fixation locations, and can be used as a submodule in models of eye movements during scene viewing. We demonstrate the utility of this idea by presenting bias-weighted gaze landscapes, and show that there is a link between the likelihood of a saccade under the flow model, and the salience of the following fixation. We also present a minor improvement to our central bias model (based on using a multivariate truncated Gaussian), and investigate the leftwards and coarse-to-fine biases in scene viewing.

Examination strategies of experienced and novice clinicians viewing the retina.

PURPOSE: Expertise in viewing medical images is thought to be due to the ability to process holistic image information. Eye care clinicians can inspect photographs of the retina to search for signs of disease. However, they commonly also view the eye in vivo using the restricted view of a slit lamp, which removes the potential benefits of holistic processing. We investigated how expert and novice clinicians inspect the fundus using these two methods. METHODS: Twenty clinicians (10 experienced, 10 novices) examined 64 photographs of human retinae. Each participant viewed half of the images as fundus photographs while having their eye position recorded. The other half were viewed via a simple slit lamp simulation, whereby a computer mouse was used to control the position of a viewing window that revealed the underlying fundus photograph. RESULTS: Experienced clinicians made decisions significantly faster than novices, with faster decision-making when viewing the fundus photograph compared to via the slit lamp simulation. The distribution of inspection was similar, although novices spent longer examining the optic nerve head than other regions. Experienced clinicians showed significantly earlier inspection of the optic nerve head when it was judged to be unhealthy. CONCLUSIONS: Our results support the idea that experienced eyecare clinicians use holistic image information, if available, when inspecting the fundus. This was particularly prominent for the optic nerve head region, which was the region that novices spent most of their time examining. Holistic processing benefits were only present in experts' free-viewing fundus photographs; the limited field of view from the slit lamp disrupts such global image benefits.

A control experiment for studies that show improved visual sensitivity with intraocular pressure lowering in glaucoma.

PURPOSE: Contrast sensitivity sometimes increases in patients with open-angle glaucoma when intraocular pressure (IOP) is decreased. Although often interpreted as demonstrating reversible glaucoma-induced dysfunction, this result, if true, could simply reflect a general relationship between sensitivity and IOP in visual mechanisms unaffected by glaucoma. To investigate this relationship, we test the hypothesis that reducing IOP in eyes without glaucoma (ocular hypertension) does not increase perimetric contrast sensitivity. DESIGN: Comparative case series. PARTICIPANTS: A total of 692 participants drawn from the Ocular Hypertension Treatment Study (OHTS) (22 clinical centers). METHODS: Commercially available topical ocular hypotensive medications. MAIN OUTCOME MEASURES: Post hoc analysis of IOP and perimetric contrast sensitivity (mean deviation [MD] and pattern standard deviation [PSD]) both at baseline (0 months, immediately before ocular antihypertensive therapy) and at 6-month review. An additional 618 control eyes from OHTS that did not receive treatment were examined over the same period. Data from the second phase of OHTS also were examined, and control eyes then received treatment. RESULTS: Treated eyes had a decrease in IOP at 6 months (5.1 mmHg, P<0.001) but no significant change in MD (0.04 decibels [dB], P = 0.59) or PSD (0.03 dB, P = 0.19), relative to controls. A similar decrease in IOP was found for eyes that began treatment in the second phase of OHTS, but no significant change in MD or PSD. CONCLUSIONS: Despite using a large sample size, we found no relationship between perimetric contrast sensitivity and IOP reduction in ocular hypertension, which suggests that previous sensitivity changes seen in patients with glaucoma, if true, are indicative of reversible glaucoma-induced dysfunction rather than a general relationship between sensitivity and IOP in visual mechanisms unaffected by glaucoma.

Target direction rather than position determines oculomotor expectation in repeating sequences.

Saccadic latencies to targets appearing to the left and right of fixation in a repeating sequence are significantly increased when a target is presented out of sequence. Is this because the target is in the wrong position, the wrong direction, or both? To find out, we arranged for targets in a horizontal plane occasionally to appear with an unexpected eccentricity, though in the correct direction. This had no significant effect on latency, unlike what is observed when targets appeared in the unexpected direction. That subjects learnt sequences of directions rather than simply positions was further confirmed in an experiment where saccade direction was a repeating sequence, but eccentricity was randomised. Latency was elevated when a target was episodically presented in an unexpected direction. Latencies were also elevated when targets appeared in the correct hemifield but at an unexpected direction (35° polar angular displacement from the horizontal, a displacement roughly equivalent in collicular spacing to our unexpected eccentricity), although this elevation was of a smaller magnitude than when targets appeared in an unexpected direction along the horizontal. Finally, we confirmed that not all changes in the stimulus cause disruption: an unexpected change in the orientation or colour of the target did not alter latency. Our results show that in a repeating sequence, the oculomotor system is primarily concerned with predicting the direction of an upcoming eye movement rather than its position. This is consistent with models of oculomotor control developed for randomly appearing targets in which the direction and amplitude of saccades are programmed separately.

Lights, Sirens, and Load: Anticipatory emergency medical treatment planning causes cognitive load during emergency response driving among paramedicine students.

Paramedics face various unconventional and secondary task demands while driving ambulances, leading to significant cognitive load, especially during lights-and-sirens responses. Previous research suggests that high cognitive load negatively affects driving performance, increasing the risk of accidents, particularly for inexperienced drivers. The current study investigated the impact of anticipatory treatment planning on cognitive load during emergency driving, as assessed through the use of a driving simulator. We recruited 28 non-paramedic participants to complete a simulated baseline drive with no task and a cognitive load manipulation using the 1-back task. We also recruited 18 paramedicine students who completed a drive while considering two cases they were travelling to: cardiac arrest and infant seizure, representing varying difficulty in required treatment. The results indicated that both cases imposed considerable cognitive load, as indicated by NASA Task Load Index responses, comparable to the 1-back task and significantly higher than driving with no load. These findings suggest that contemplating cases and treatment plans may impact the safety of novice paramedics driving ambulances for emergency response. Further research should explore the influence of experience and the presence of a second individual in the vehicle to generalise to broader emergency response driving contexts.

The time-course of visual scanning behaviour of paramedicine students upon arrival at a simulated emergency call.

BACKGROUND: Limited knowledge exists regarding how paramedics acquire an understanding of the scene they encounter upon arrival, despite their need to quickly gather information for effective clinical decision-making. This study examined visual scanning behaviour during the early stages of simulated emergency calls. METHODS: Eye movements of 10 paramedicine students were recorded during simulated calls conducted in both a high-fidelity classroom setting and a full sensory immersion setting. RESULTS: Students focused on similar areas in both settings, with most time spent looking at the patient rather than distractors such as room features or other people. Analysis of gaze behaviour across the first five minutes revealed a more nuanced pattern: attention initially gravitated towards distractors but decreased as students became familiar with their surroundings and focused on the task at hand. This pattern was consistent across both simulation settings, indicating that information-seeking strategies may be independent of scene complexity. CONCLUSIONS: Expertise relies on the ability to differentiate between relevant and irrelevant information. Given the unpredictable nature of their work, paramedics must continuously adapt their understanding of a scene from the moment they enter it. Understanding how this skill develops may help identify expert strategies to inform training of novice paramedics.

Decision-making in single and multiple-screen CCTV surveillance.

One task of CCTV operation is to decide whether footage shown in videos depicts criminal behaviour, or allows a viewer to predict its occurrence. An increasing prevalence of cameras in the world, means an increase in screens in the control room. This presents a signal-to-noise challenge where the signal (criminal activity) may become more difficult to detect amongst the noise. We used signal detection approaches to understand which factors were associated with decision-making in a CCTV task. When detecting aggressive incidents, higher conscientiousness was associated with making better decisions, with a higher criterion for responding (meaning fewer false-positive responses). However, conscientious individuals tended to be less confident (in multiplex displays), and were slower in responding - which reflects that these individuals require more evidence to make these decisions. Higher trait cognitive anxiety was again associated with making earlier responses, while extraversion was also associated with earlier responding in multiplexed displays. Taken in combination, our results suggest that there is a fine balance between making correct decisions, and making early decisions - and that these need to be considered together in the CCTV task.

Object Properties Influence Visual Guidance of Motor Actions.

The dynamic nature of the real world poses challenges for predicting where best to allocate gaze during object interactions. The same object may require different visual guidance depending on its current or upcoming state. Here, we explore how object properties (the material and shape of objects) and object state (whether it is full of liquid, or to be set down in a crowded location) influence visual supervision while setting objects down, which is an element of object interaction that has been relatively neglected in the literature. In a liquid pouring task, we asked participants to move empty glasses to a filling station; to leave them empty, half fill, or completely fill them with water; and then move them again to a tray. During the first putdown (when the glasses were all empty), visual guidance was determined only by the type of glass being set down-with more unwieldy champagne flutes being more likely to be guided than other types of glasses. However, when the glasses were then filled, glass type no longer mattered, with the material and fill level predicting whether the glasses were set down with visual supervision: full, glass material containers were more likely to be guided than empty, plastic ones. The key finding from this research is that the visual system responds flexibly to dynamic changes in object properties, likely based on predictions of risk associated with setting-down the object unsupervised by vision. The factors that govern these mechanisms can vary within the same object as it changes state.

Anxious individuals predict the onset of aggression earlier in a CCTV surveillance task.

Attentional biases in anxious individuals can facilitate the detection of threatening stimuli. A particular field of research that may benefit from enhanced threat detection is in closed-circuit television (CCTV) surveillance, in which operators search through multiple camera feeds to attempt to identify threatening situations before they occur. The present study examined whether the enhanced threat detection of anxious individuals extends to the ability to detect threat in a multiple-scene CCTV task. Anxiety was measured in a nonclinical sample using the State-Trait Inventory for Cognitive and Somatic Anxiety. Participants were asked to try to find aggressive incidents that were simulated using the game Grand Theft Auto V in displays showing 1, 4, or 9 simultaneous videos. The results revealed that higher levels of trait cognitive, state cognitive, and trait somatic anxiety were related to earlier responses, with no change in confidence or accuracy. Increasing the number of screens to be monitored was associated with detecting the events later and a reduced confidence in responses. These results suggest that, in nonclinical populations, a moderate degree of anxiety may be beneficial in predicting acts of aggression during CCTV monitoring tasks. Trait (i.e., stable) levels of anxiety may inform recruitment of operators for surveillance tasks. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Is experience in multi-genre video game playing accompanied by impulsivity?

Developing impulsivity has been one of the main concerns thought to arise from the increasing popularity of video gaming. Most of the relevant literature has treated gamers as pure-genre players (i.e. those who play only a specific genre of game). However, it is not clear how impulsivity is associated with different genres of games in multi-genre gamers, given that there is increasing diversity in the games played by individuals. In this study, we compared 33 gamers to 23 non-gamers in a go/no-go task: the Continuous Performance Test (CPT). To evaluate whether or not impulsivity occurs as a trade-off between speed and accuracy, we emphasised fast performance to all participants. Then, to examine the ability to predict impulsivity from game genre-hours, we fitted separate multiple regression models to several dependent variables. As an additional measure, we also compared groups in an antisaccade task. In the CPT, gamers showed a trend towards significantly faster reaction time (RT), accompanied by higher false alarm rate (FAR) and more risk-taking response bias (ß), suggesting impulsive responses. Interestingly, there was a significant negative correlation between RT and FAR across all participants, suggesting an overall speed-accuracy trade-off strategy, perhaps driven by the emphasis on speed during task instruction. Moreover, time spent on role playing games (RPG) and real-time strategy (RTS) games better predicted FAR and ß than did time spent on action and puzzle games. In the antisaccade task; however, gamers showed a shorter antisaccade latency but a comparable error rate in comparison with non-gamers. There was no specific game genre which could predict performance in the antisaccade task. Altogether, there was no evidence of oculomotor impulsivity in gamers; however, the CPT results suggested the presence of impulsive responses in gamers, which might be the result of a speed-accuracy trade-off. Furthermore, there was a difference in game genres, with time spent on RPG and RTS games being accompanied by greater probability of impulsive responses. Training studies are required to investigate the causality of different video game genres on the development of impulsivity.

Coordinating vision and action in natural behaviour: Differences in spatiotemporal coupling in everyday tasks.

Vision and action are tightly coupled in space and time: for many tasks we must look at the right place at the right time to gather the information that we need to complete our behavioural goals. Vision typically leads action by about 0.5 seconds in many natural tasks. However, the factors that influence this temporal coordination are not well understood, and variations have been found previously between two domestic tasks each with similar constraints: tea making and sandwich making. This study offers a systematic exploration of the factors that govern spatiotemporal coordination of vision and action within complex real-world activities. We found that the temporal coordination eye movements and action differed between tea making and sandwich making. Longer eye-hand latencies, more "look ahead" fixations and more looks to irrelevant objects were found when making tea than when making a sandwich. Contrary to previous suggestions, we found that the requirement to move around the environment did not influence the coordination of vision and action. We conclude that the dynamics of visual behaviour during motor acts are sensitive to the task and specific objects and actions required but not to the spatial demands requiring movement around an environment. (PsycINFO Database Record

The influence of action video game playing on eye movement behaviour during visual search in abstract, in-game and natural scenes.

Action game playing has been associated with several improvements in visual attention tasks. However, it is not clear how such changes might influence the way we overtly select information from our visual world (i.e. eye movements). We examined whether action-video-game training changed eye movement behaviour in a series of visual search tasks including conjunctive search (relatively abstracted from natural behaviour), game-related search, and more naturalistic scene search. Forty nongamers were trained in either an action first-person shooter game or a card game (control) for 10 hours. As a further control, we recorded eye movements of 20 experienced action gamers on the same tasks. The results did not show any change in duration of fixations or saccade amplitude either from before to after the training or between all nongamers (pretraining) and experienced action gamers. However, we observed a change in search strategy, reflected by a reduction in the vertical distribution of fixations for the game-related search task in the action-game-trained group. This might suggest learning the likely distribution of targets. In other words, game training only skilled participants to search game images for targets important to the game, with no indication of transfer to the more natural scene search. Taken together, these results suggest no modification in overt allocation of attention. Either the skills that can be trained with action gaming are not powerful enough to influence information selection through eye movements, or action-game-learned skills are not used when deciding where to move the eyes.

On the Factors Causing Processing Difficulty of Multiple-Scene Displays.

Multiplex viewing of static or dynamic scenes is an increasing feature of screen media. Most existing multiplex experiments have examined detection across increasing scene numbers, but currently no systematic evaluation of the factors that might produce difficulty in processing multiplexes exists. Across five experiments we provide such an evaluation. Experiment 1 characterises difficulty in change detection when the number of scenes is increased. Experiment 2 reveals that the increased difficulty across multiple-scene displays is caused by the total amount of visual information accounts for differences in change detection times, regardless of whether this information is presented across multiple scenes, or contained in one scene. Experiment 3 shows that whether quadrants of a display were drawn from the same, or different scenes did not affect change detection performance. Experiment 4 demonstrates that knowing which scene the change will occur in means participants can perform at monoplex level. Finally, Experiment 5 finds that changes of central interest in multiplexed scenes are detected far easier than marginal interest changes to such an extent that a centrally interesting object removal in nine screens is detected more rapidly than a marginally interesting object removal in four screens. Processing multiple-screen displays therefore seems dependent on the amount of information, and the importance of that information to the task, rather than simply the number of scenes in the display. We discuss the theoretical and applied implications of these findings.

Sequences show rapid motor transfer and spatial translation in the oculomotor system.

Every day we perform learnt sequences of actions that seem to happen almost without awareness. It has been argued that for learning such sequences parallel learning networks exist - one using spatial coordinates and one using motor coordinates - with sequence acquisition involving a progressive shift from the former to the latter as a sequence is rehearsed. When sequences are interrupted by an out-of-sequence target, there is a delay in the response to the target, and so here we transiently interrupt oculomotor sequences to probe the influence of oculomotor rehearsal and spatial coordinates in sequence acquisition. For our main experiments, we used a repeating sequences of eight targets in length that was first learnt either using saccadic eye movements (left/right), manual responses (left/right or up/down) or as a sequence of colour (blue/red) requiring no motor response. The sequence was immediately repeated for saccadic eye movements, during which the influence of on out-of-sequence target (an interruption) was assessed. When a sequence is learnt beforehand in an abstract way (for example, as a sequence of colours or of orthogonally mapped manual responses), interruptions are immediately disruptive to latency, suggesting neither motor rehearsal nor specific spatial coordinates are essential for encoding sequences of actions and that sequences - no matter how they are encoded - can be rapidly translated into oculomotor coordinates. The magnitude of a disruption does, however, correspond to how well a sequence is learnt: introducing an interruption to an extended sequence before it was reliably learnt reduces the magnitude of the latency disruption.

Longitudinal assessment of reflexive and volitional saccades in Niemann-Pick Type C disease during treatment with miglustat.

BACKGROUND: Niemann-Pick Type C disease (NPC), is an autosomal recessive neurovisceral disorder of lipid metabolism. One characteristic feature of NPC is a vertical supranuclear gaze palsy particularly affecting saccades. However, horizontal saccades are also impaired and as a consequence a parameter related to horizontal peak saccadic velocity was used as an outcome measure in the clinical trial of miglustat, the first drug approved in several jurisdictions for the treatment of NPC. As NPC-related neuropathology is widespread in the brain we examined a wider range of horizontal saccade parameters and to determine whether these showed treatment-related improvement and, if so, if this was maintained over time. METHODS: Nine adult NPC patients participated in the study; 8 were treated with miglustat for periods between 33 and 61 months. Data were available for 2 patients before their treatment commenced and 1 patient was untreated. Tasks included reflexive saccades, antisaccades and self-paced saccades, with eye movements recorded by an infrared reflectance eye tracker. Parameters analysed were reflexive saccade gain and latency, asymptotic peak saccadic velocity, HSEM-α (the slope of the peak duration-amplitude regression line), antisaccade error percentage, self-paced saccade count and time between refixations on the self-paced task. Data were analysed by plotting the change from baseline as a proportion of the baseline value at each test time and, where multiple data values were available at each session, by linear mixed effects (LME) analysis. RESULTS: Examination of change plots suggested some modest sustained improvement in gain, no consistent changes in asymptotic peak velocity or HSEM-α, deterioration in the already poor antisaccade error rate and sustained improvement in self-paced saccade rate. LME analysis showed statistically significant improvement in gain and the interval between self-paced saccades, with differences over time between treated and untreated patients. CONCLUSIONS: Both qualitative examination of change scores and statistical evaluation with LME analysis support the idea that some saccadic parameters are robust indicators of efficacy, and that the variability observed across measures may indicate locally different effects of neurodegeneration and of drug actions.

Behavioral biases when viewing multiplexed scenes: scene structure and frames of reference for inspection.

Where people look when viewing a scene has been a much explored avenue of vision research (e.g., see Tatler, 2009). Current understanding of eye guidance suggests that a combination of high and low-level factors influence fixation selection (e.g., Torralba et al., 2006), but that there are also strong biases toward the center of an image (Tatler, 2007). However, situations where we view multiplexed scenes are becoming increasingly common, and it is unclear how visual inspection might be arranged when content lacks normal semantic or spatial structure. Here we use the central bias to examine how gaze behavior is organized in scenes that are presented in their normal format, or disrupted by scrambling the quadrants and separating them by space. In Experiment 1, scrambling scenes had the strongest influence on gaze allocation. Observers were highly biased by the quadrant center, although physical space did not enhance this bias. However, the center of the display still contributed to fixation selection above chance, and was most influential early in scene viewing. When the top left quadrant was held constant across all conditions in Experiment 2, fixation behavior was significantly influenced by the overall arrangement of the display, with fixations being biased toward the quadrant center when the other three quadrants were scrambled (despite the visual information in this quadrant being identical in all conditions). When scenes are scrambled into four quadrants and semantic contiguity is disrupted, observers no longer appear to view the content as a single scene (despite it consisting of the same visual information overall), but rather anchor visual inspection around the four separate "sub-scenes." Moreover, the frame of reference that observers use when viewing the multiplex seems to change across viewing time: from an early bias toward the display center to a later bias toward quadrant centers.

Looking for trouble: a description of oculomotor search strategies during live CCTV operation.

Recent research has begun to address how CCTV operators in the modern control room attempt to search for crime (e.g., Howard et al., 2011). However, an often-neglected element of the CCTV task is that the operators have at their disposal a multiplexed wall of scenes, and a single spot-monitor on which they can select any of these feeds for inspection. Here we examined how 2 trained CCTV operators used these sources of information to search from crime during a morning, afternoon, and night-time shift. We found that they spent surprisingly little time viewing the multiplex wall, instead preferentially spending most of their time searching on the single-scene spot-monitor. Such search must require a sophisticated understanding of the surveilled environment, as the operators must make their selection of which screen to view based on their prediction of where crime is likely to occur. This seems to be reflected in the difference in the screens that they selected to view at different times of the day. For example, night-clubs received close monitoring at night, but were seldom viewed in mid-morning. Such narrowing of search based on a contextual understanding of an environment is not a new idea (e.g., Torralba et al., 2006), and appears to contribute to operator's selection strategy. This research prompts new questions regarding the nature of representation that operators have of their environment, and how they might develop expectation-based search strategies to countermand the demands of the large influx of visual information. Future research should ensure not to neglect examination of operator behavior "in the wild" (Hutchins, 1995a), as such insights are difficult to gain from laboratory based paradigms alone.