Introduction

"Working is a favor when it helps us think about what we are doing."

Mossi Proverb, West African People

Patient safety is closely linked to the quality of the working conditions of healthcare professionals. A challenging environment for healthcare professionals is a source of errors, as it induces discomfort, stress and fatigue. Workplace hardship is defined in the French Labor Code as encompassing three factors:

• physical constraints: handling loads, awkward postures, vibrations, etc.;
• a harsh physical environment: toxic chemical agents, noise, ambient temperature, etc.;
• the pace of work: night work in successive and alternating shifts, repetitive work, etc.

The working conditions of many healthcare professionals often "tick" these three boxes, making this sector particularly demanding. To improve these working conditions, physical ergonomics1 (analyzing gestures and postures, environmental factors such as acoustics, lighting, temperature, etc.) provides concepts, methods and recommendations that can lead to design or redesign proposals for a given workstation. Using physical ergonomics means both providing solutions to healthcare professionals and reducing the likelihood of adverse events affecting the health of caregivers and patients.

However, discomfort, stress and fatigue - the primary stressors generated by unsuitable working conditions - may also be linked to another aspect of the job. This other aspect pertains to the informational environment in which healthcare professionals are immersed. Information from patients, colleagues or an increasing number of information systems, coupled with a substantial amount of knowledge required to comprehend each care situation, often leads to an excessively high mental workload. The influx of information from transmitters and receivers (patients, colleagues, alarms, phone calls, etc.) interrupts tasks or time-sharing, disrupting trains of thought. This over-solicitation of mental activity poses risks of forgetfulness or confusion, potentially resulting in errors. Here, cognitive ergonomics, a branch of ergonomics, can offer concepts, methods and ultimately solutions to facilitate information management, reduce psychological discomfort, mental fatigue, stress and error frequency. Moreover, it has been established that musculoskeletal disorders can be caused not only by improper gestures, postures and work rhythms but also by cognitive and/or psychological overexertion (ANACT 2008; Zelano 2014). In other words, the issue of physical strain intersects with that of mental strain.

Concretely, one way to impmve the informational workingenvironment is to make cognitive aids available to caregivers.Cognitive aids are intended to relieve the mental workload2, reduce the risks associated with task interruptions or multitasking contexts, and ensure care reliability with regard to good practices. Also, if a cognitive aid is not yet available "off the shelf',it is possible to design one from scratch. Health professionals and managers of medical facilities obviously did not wait for ergonomists to design their cognitive aids. However, it is necessary to emphasize that the implementation of a cognitive aid is not an insignificant intervention. It is a journey fraught with pitfalls that, in some cases, can lead to devices that, despite the laudable intentions of their designers, do not achieve their objectives or even constitute an additional constraint leading to explicit or implicit rejection by users. To achieve an effective means of improving the cognitive conditions of work, a cognitive aid must undergo in-depth reflection regarding its purposes and the consequences on the work situation. The pitfalls that cognitive aid designers face are potentially multifold. They can arise from doubts or even negative prejudices within teams regarding the impact of such a device on their working conditions. Paradoxically, designers may also struggle with their own biases regarding the ease of developing an aid and the assurance of achieving a positive impact on working conditions.

We will have the opportunity to elaborate on the barriers that have been observed in the field during the integration of a new cognitive aid. However, we can already mention the bureaucratic aspect of a cognitive aid embedding itself in the format of a new form in daily activities. On a workstation already burdened with multiple constraints, adding what would be an additional constraint is inherently very risky, and in this regard, we can fully understand the apprehensions of future users regarding a new work document, whether it is in paper or digital format.

Other blocking points can arise from the unwise enthusiasm that designers invest in their cognitive aid projects. Many cognitive aids used in the field of health or in other domains, where safety and complexity issues to be managed are equally crucial, are manifested through a simple sheet of paper on which instructions are to be followed or information is to be verified. Taking the example of the checklist, which represents the "primary" cognitive aid in the workplace, it essentially involves ticking a series of checkboxes on a piece of paper. For a cognitive aid designer, this implies that merely writing on a sheet placed on the edge of a table, based on their personal representation of work, is sufficient to create a cognitive aid.

Another false hope, more sophisticated in nature, involves the mere transfer, without adaptation, of cognitive aids used in other domains, such as aeronautics, directly to the realm of healthcare, with the expectation of yielding effective devices. While, as we will explore, endeavors in risk management and cognitive aid design originating from aeronautics have indeed facilitated, and continue to facilitate, substantial advancements in the healthcare sector, these endeavors do not provide comprehensive solutions. Healthcare professionals undeniably encounter specific work constraints distinct from those of airplane pilots. Therefore, it is imperative to acknowledge and address these constraints accordingly.

Confronted with these potential pitfalls, intentionally exaggerated here to underscore them, as well as numerous other pitfalls worthy of recognition, the reader must be cautioned that cognitive ergonomics3 does not offer ready-made solutions for designing cognitive aids. In this book, we will explore ergonomic recommendations, albeit primarily limited to providing general advice on information presentation within a working document. The contributions of ergonomics are primarily elsewhere.

Conceptually, cognitive ergonomics, rooted in cognitive psychology, demonstrates how cognitive aids naturally integrate into human information processing strategies on a daily basis, functioning as psychological instruments.

Through its theoretical assumptions, cognitive ergonomics posits that a workstation or service fundamentally constitutes a system with a certain dynamic equilibrium point. Consequently, the introduction of a new cognitive aid involves a transient imbalance, ultimately leading to the establishment of a new equilibrium point that may not necessarily be more satisfactory than the previous one.

Finally, a crucial contribution of cognitive ergonomics lies in the methodological realm. While general recommendations often have limited applicability, analysis of the work practices of prospective users of cognitive aids is an essential method to ensure that the device meets the needs of the field and does not become an additional constraint imposed upon the work system.

The aim of this book is to illustrate the various contributions of cognitive ergonomics for both designers and users of cognitive aids. The initial phase of this inquiry centers on the fundamental objectives of cognitive aids (Part 1). From this foundation, the specific functions of individual cognitive aids are delineated (Chapter 1). It becomes apparent that cognitive aids serve as conduits between an individual's internal cognition and the external cognition embedded within the environment (Chapter 2). While knowledge often resides initially within the minds of healthcare providers, the implementation of cognitive aids facilitates the transfer of this knowledge to the external environment, thus engendering distributed cognition. Moreover, the introduction of cognitive aids frequently involves a shift in information processing strategies among users, transitioning from intuition-based reasoning to the analytical thinking facilitated by cognitive aids (Chapter 3). Nonetheless, it is also demonstrated that a move towards increased intuition, facilitated by certain aids, can be both feasible and beneficial (Chapter 4). Furthermore, cognitive aids serve as frameworks for providing directives and work procedures, thereby integrating into communication methods for instructing personnel navigating the complexities of real-world constraints (Chapter 5).

Lastly, the reader will discover methodological elements fordesigning a cognitive aid as a comprehensive information system, capable of providing fundamentally relevant information (Part 2).This objective will involve modeling cognitiveaids as Turing machines. Consequently, a cognitive aid can beconceptualized as both a strip of tape used by an agent to store information (Chapter 6) and/or as a network of mental states of the agent using this tape (Chapter 7). Each perspective will bring forth its array of methods and techniques for work analysis, reasonably enabling us to aspire to devices that...