Pupillometry as a tool to study expertise in medicine

Background Pupillometry has been studied as a physiological marker for quantifying cognitive load since the early 1960s. It has been established that small changes in pupillary size can provide an index of the cognitive load of a participant as he/she performs a mental task. The utility of pupillometry as a measure of expertise is less well established, although recent research in the fields of education, medicine and psychology indicates that differences in pupillary size during domain-specific tasks allows differentiation between experts and novices in appropriately designed experiments.Purpose The goal of this review is to explore the existing body of evidence for the use of pupillometry as a measure of expertise and to identify its strengths and constraints within the context of expertise research in the medical sciences.Results Pupillometry is a robust metric that allows researchers to better understand cognitive load in medical practitioners with varying levels of expertise. In medical expertise research, it has been used to study surgeons, anesthetists and emergency physicians. Its strengths include its ability to provide quantitative and objective outputs, to be measured unobtrusively with new technology and to be precisely computed as cognitive load changes over the course of completion of a task. Constraints associated with this methodology include its potential inaccuracy with changes in ambient light and pupillary accommodation as well as the need for relatively expensive equipment. Conclusion With recent technological advances, pupillometry has become a simple and robust method for quantifying physiological changes attributable to cognitive load and is increasingly being utilized in medical education. It can be used as a reliable marker of mental effort and has been shown to differentiate levels of expertise in medical practitioners

A USER’S COGNITIVE WORKLOAD PERSPECTIVE IN NEGOTIATION SUPPORT SYSTEMS: AN EYE-TRACKING EXPERIMENT

Replying to several research calls, I report promising results from an initial experiment which com-pares different negotiation support system approaches concerning their potential to reduce a user’s cognitive workload. Using a novel laboratory-based non-intrusive objective measurement technique which derives the user’s cognitive workload from pupillary responses and eye-movements, I experi-mentally evaluated a standard, a chat-based, and an argumentation-based negotiation support system and found that a higher assistance level of negotiation support systems actually leads to a lower user’s cognitive workload. In more detail, I found that an argumentation-based system which fully automates the generation of the user’s arguments significantly decreases the user’s cognitive workload compared to a standard system. In addition I found that a negotiation support system implementing an additional chat function significantly causes higher cognitive workload for users compared to a standard system

Measuring cognitive state from physiological signals in user interface research

The purpose of this Thesis is to investigate how modern technology can be used for evaluating human cognitive state in the context of human-computer interaction, namely user interface (UI) research. In this work two types of physiological data were collected to measure cognitive load during a task which requires some degree of human-computer interaction. A near-infrared spectroscopy device and eye tacker were used to evaluate cognitive load level during the task and provide an insight into how these data might be used in an adaptive real-time system. A mental calculation task was used as the cognitively demanding learning task, which challenges working memory. Additional difficulty was added using the task presentation: mathematical expressions were either static or moving from the top to the bottom of the screen. Results indicate that tasks of different mental complexity elicit different cognitive responses. With careful interpretation this information can be used in designing environments, suitable for the user. This work have shown that in designing the systems which use physiological measurements, it is crucial to know the possible sources of the noise. For example, in pupillary measurements it is important to control for luminance and physiological changes which affect pupil size along with cognitive load, or to develop methods which discriminate between task-evoked pupil response from other responses. For any real-time system it is necessary to develop the fast and efficient algorithms which produce reliable results with minimal training of the models

Monitoring Cognitive and Emotional Processes Through Pupil and Cardiac Response During Dynamic Versus Logical Task

The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error

Mental workload and visual impairment: differences between pupil, blink, and subjective rating

Este experimento tiene dos objetivos: 1) Estudiar la validez concurrente de tres medidas de carga mental, la escala de juicios NASA TLX, la dilatación de la pupila y la tasa de parpadeo, poniendo a prueba la hipótesis de que, en situaciones de tarea única, arrojan resultados convergentes, pero, en doble tarea, arrojan resultados disociativos. 2) Analizar su capacidad para predecir el deterioro en la búsqueda visual. Las tres medidas fueron analizadas con las mismas tareas cognitivas realizadas en condiciones de tarea simple y de doble tarea (tarea cognitiva y búsqueda visual) en un experimento intrasujetos con veintinueve participantes. Las medidas de carga mental mostraron validez concurrente en las condiciones de tarea única, pero en las condiciones de doble tarea apareció un patrón de resultados complejo que sugiere que NASA TLX consistiría en la adición subjetiva de los juicios de cada tarea; la dilatación de la pupila mediría la activación promedio que subyace a las tareas cognitivas; y la tasa de parpadeo produciría efectos contrapuestos: mientras que la carga mental de las tareas cognitivas incrementa la tasa de parpadeo, las demandas visuales la inhiben. Las tres medidas fueros buenos predoctores del deterioro visual. Se discute la justificación del uso de estas medidas en el campo aplicado de la conducción y otras actividades.This research has two aims: (a) To study the concurrent validity of three measures of mental workload, NASA TLX rating scale, pupil dilation and blink rate, testing the hypothesis that they will provide convergent results using a single-task, and dissociative results for dual-task; and (b) To analyse their capability to predict visual search impairment. These three measures were analyzed in the same cognitive tasks in singletask and dual-task (cognitive task and visual search) conditions in a within-subjects experiment with twenty-nine participants. Mental workload measures showed concurrent validity under single-task condition, but a complex pattern of results arose in the dualtask condition: it is suggested that NASA TLX would be a subjective addition of the rating of each task; pupil dilation would measure the average arousal underlying the cognitive tasks; and the blink rate would produce opposite effects: whereas mental workload of cognitive tasks would increase blink rate, visual demand would inhibit it. All three measures were good predictors of visual impairment. The soundness of these measures is discussed with regard to the applied field of driving and other activities