Edith Galy

Mental workload and driving

The aim of this review is to identify the most representative measures of subjective and objective mental workload in driving, and to understand how the subjective and objective levels of mental workload influence the performance as a function of situation complexity and driving experience, i.e., to verify whether the increase of situation complexity and the lack of experience increase the subjective and physiological levels of mental workload and lead to driving performance impairments. This review will be useful to both researchers designing an experimental study of mental workload and to designers of drivers’ training content. In the first part, we will broach the theoretical approach with two factors of mental workload and performance, i.e., situation complexity and driving experience. Indeed, a low complex situation (e.g., highways), or conversely a high complex situation (e.g., town) can provoke an overload. Additionally, performing the driving tasks implies producing a high effort for novice drivers who have not totally automated the driving activity. In the second part, we will focus on subjective measures of mental workload. A comparison of questionnaires usually used in driving will allow identifying the most appropriate ones as a function of different criteria. Moreover, we will review the empirical studies to verify if the subjective level of mental workload is high in simple and very complex situations, especially for novice drivers compared to the experienced ones. In the third part, we will focus on physiological measures. A comparison of physiological indicators will be realized in order to identify the most correlated to mental workload. An empirical review will also take the effect of situation complexity and experience on these physiological indicators into consideration. Finally, a more nuanced comparison between subjective and physiological measures will be established from the impact on situation complexity and experience.

SEQUENCE CLASS FORMATION FOLLOWING LEARNING OF SHORT SEQUENCES

The production of 3-item probe sequences by 20 adults was assessed after the participants were trained to respond to three 3-item sequences (A1→A2→A3, B1→B2→B3, and C1→C2→C3). Each sequence was learned progressively according to the successive phase method (1-item phase, 2-item phase, and then 3-item phase). Performance on the 3 probe sequences was consistent with the formation of classes of mutually substitutable sequence stimuli. Elsewhere, learning of these functional classes was enhanced when subjects were trained with a 5-min compared to a 24-hr intersessions delay. These results were discussed according to experimental conditions and acquisition of learning rules knowledge.

Overload depending on driving experience and situation complexity: Which strategies faced with a pedestrian crossing?

The purpose of this study was to identify the influence of situation complexity and driving experience on subjective workload and driving performance, and the less costly and the most effective strategies faced with a hazard pedestrian crossing. Four groups of young drivers (15 traditionally trained novices, 12 early-trained novices, 15 with three years of experience and 15 with a minimum of five years of experience) were randomly assigned to three situations (simple, moderately complex and very complex) including unexpected pedestrian crossings, in a driving simulator. The subjective workload was collected by the NASA-TLX questionnaire after each situation. The main results confirmed that the situation complexity and the lack of experience increased the subjective workload. Moreover, the subjective workload, the avoidance strategies and the reaction times influenced the number of collisions depending on situation complexity and driving experience. These results must be taken into account to target the prevention actions.

Recall Performance in Air Traffic Controllers Across the 24-hr Day: Influence of Alertness and Task Demands on Recall Strategies

© 2012 Melan and Galy, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Recall Performance in Air Traffic Controllers Across the 24-hr Day: Influence of Alertness and Task Demands on Recall Strategies

Measuring mental workload with the NASA-TLX needs to examine each dimension rather than relying on the global score: an example with driving

Abstract The distinction between several components of mental workload is often made in the ergonomics literature. However, measurements used are often established from a global score, notably with several questionnaires that originally reflect several dimensions. The present study tested the effect of driving situation complexity, experience and subjective levels of tension and alertness on each dimension of the NASA-TLX questionnaire of workload, in order to highlight the potential influence of intrinsic, extraneous and germane load factors. The results showed that, in complex situation, mental, temporal and physical demand (load dimensions) increased, and that novice drivers presented high physical demand when subjective tension was low on performance. Moreover, increase of mental and physical demand increased effort. It thus, appears essential to distinguish the different components of mental workload used in the NASA-TLX questionnaire. Practitioner Summary: Currently, global score of NASA-TLX questionnaire is used to measure mental workload. Here, we considered independently each dimension of NASA-TLX, and results showed that mental load factors (driving situation complexity, experience, subjective tension and alertness) had a different effect on dimensions, questioning global score use to evaluate workload.

Consideration of several mental workload categories: perspectives for elaboration of new ergonomic recommendations concerning shiftwork

ABSTRACT In this article, a reflection is presented concerning consideration of several mental workloads in ergonomics to describe work situation. For that, results of three experiments are recalled and put into perspective to understand relationships between mental workload and performance, and between different measures of mental workload. A integrative model IWA for individual – mental workload – activity is presented to explain interactions between task parameters, individual characteristics and contextual characteristics showing relevance to consider all the elements of a work situation to can estimate the more correctly possible mental workload supported by operator. Then, discussion on relevance of mental workload measures permits to highlight the lack of exhaustive measures of different components of mental workload. Finally, methodological propositions with a diagnostic or prognostic approach are presented in order to consider all elements described in model IWA.