A Field Study Assessing Driving Performance, Visual Attention, Heart Rate and Subjective Ratings in Response to Two Types of Cognitive Workload

In an on-road experiment, driving performance, visual attention, heart rate and subjective ratings of workload were evaluated in response to a working memory (n-back) and a visual-spatial (clock) task. Subjective workload ratings for the two types of tasks did not statistically differ, suggesting a similar level of overall workload. Gaze concentration and heart rate showed significant changes relative to single task driving during the extra tasks and the magnitude of change was similar for both, while driving performance measures were not sensitive to the increase in workload. The results suggest high sensitivity of both gaze dispersion and heart rate as measures of workload across these two different types of cognitive demand

The Incredible Shrinking Letter: How Font Size Affects the Legibility of Text Viewed in Brief Glances

As in-vehicle interfaces have become miniature computers with userfacing LCD screens, the complexities of designing for them have increased tremendously. Given their safety-critical nature, designers must carefully consider every aspect of the vehicle’s digital interface. Recent research has suggested that even the typeface used to display the interface’s text can have significant impacts on driver behaviors such as total off-road glance time and secondary task completion time. Here we outline a psychophysical method for rapidly assessing the glance-based legibility of two different typefaces (a “humanist” and a “square grotesque”) presented in two different sizes (3mm and 4mm). Consistent with previous research, we find that humanist type is more legible than square grotesque. We also find that text is empirically less legible at 3mm compared to 4mm, and that this effect is especially pronounced for the square grotesque typeface. Legibility thresholds were also found to increase linearly with age, more than doubling across the age range studied. We hypothesize that the square grotesque’s intrinsic design characteristics cause it to scale poorly at small sizes and lose important details, especially in suboptimal display conditions

A Secondary Assessment of the Impact of Voice Interface Turn Delays on Driver Attention and Arousal in Field Conditions

Voice interface use has become increasingly popular in vehicles. It is important that these systems divert drivers’ attention from the primary driving task as little as possible, and numerous efforts have been devoted to categorizing demands associated with these systems. Nonetheless, there is still much to be learned about how various implementation characteristics impact attention. This study presents a secondary analysis of the delay time between when users finish giving commands and when the system responds. It considers data collected on 4 different production vehicle voice interfaces and a mounted smartphone in field driving. Collapsing across systems, drivers showed an initial increase in heart rate, skin conductance level, and off-road glance time while waiting for a system to respond; a gradual decrease followed as delays continued. The observed attentional and arousal changes are likely due to an increase in anticipation following a speech command, followed by a general disengagement from the interface as delay times increase. Safety concerns associated with extended delay times and suggestion of an optimal range for system response times are highlighted

Assessing the Impact of “Brain Training” on Changes in Driving Performance, Visual Behavior, and Neuropsychological Measures

As the population has become both older and more technologically literate, a new class of “brain training” computer programs have gained in popularity. Though these programs have attracted substantial attention from scientists and consumers, the extent of their benefits, if any, remain unclear. Here we employ neuropsychological tests and behavioral metrics collected during periods of real-world driving (with and without manipulations of cognitive load) to evaluate the effects of training with Posit Science’s DriveSharp software. We find that DriveSharp’s training effects appear in in-lab measures of Useful Field of View but did not translate to changes in actual driving performance or changes in visual behavior in consistent or quantifiable ways in the sample assessed. The implications of these results and relevant limitations of the present research are discussed

Assessing the impact of typeface design in a text-rich automotive user interface

Text-rich driver–vehicle interfaces are increasingly common in new vehicles, yet the effects of different typeface characteristics on task performance in this brief off-road based glance context remains sparsely examined. Subjects completed menu selection tasks while in a driving simulator. Menu text was set either in a ‘humanist’ or ‘square grotesque’ typeface. Among men, use of the humanist typeface resulted in a 10.6% reduction in total glance time as compared to the square grotesque typeface. Total response time and number of glances showed similar reductions. The impact of typeface was either more modest or not apparent for women. Error rates for both males and females were 3.1% lower for the humanist typeface. This research suggests that optimised typefaces may mitigate some interface demands. Future work will need to assess whether other typeface characteristics can be optimised to further reduce demand, improve legibility, increase usability and help meet new governmental distraction guidelines

The bashful and the boastful : prestigious leaders and social change in Mesolithic Societies

The creation and maintenance of influential leaders and authorities is one of the key themes of archaeological and historical enquiry. However the social dynamics of authorities and leaders in the Mesolithic remains a largely unexplored area of study. The role and influence of authorities can be remarkably different in different situations yet they exist in all societies and in almost all social contexts from playgrounds to parliaments. Here we explore the literature on the dynamics of authority creation, maintenance and contestation in egalitarian societies, and discuss the implications for our interpretation and understanding of the formation of authorities and leaders and changing social relationships within the Mesolithic

Crafting History: How the World Is Made. The Case of Islamic Archaeology

In this paper an archaeological and theoretical perspective that builds a relationship between the concepts of craft and of identity is presented. Both of them are concepts very widely used in archaeological and anthropological theory nowadays, and they have often been linked in field studies. However, these concepts are usually contemplated from very different points of view and with many diverse implications in each case. One of the aims of this paper is to show that craft and identity can be inserted in a common theoretical framework which in turn can be used to understand cultural change or, in other words, history within culture. The paper will start with a necessary theoretical introduction to different concepts related to craft and identity, and then a discussion on how to link these different concepts will follow. In the last part of the paper, this theoretical perspective will be applied to a field which is familiar to the author, that of Islamic archaeology. A case example of the author’s research in the Vega of Granada (southeast Spain) will be brought to the fore. This part of the paper will show how the theoretical discussion developed above can contribute to solve one of the core questions of this field, that of the definition of an Islamic culture and its application to understand the daily life of people living within it

Historicising Material Agency: from Relations to Relational Constellations

Relational approaches have gradually been changing the face of archaeology over the last decade: analytically, through formal network analysis; and interpretively, with various frameworks of human-thing relations. Their popularity has been such, however, that it threatens to undermine their relevance. If everyone agrees that we should understand past worlds by tracing relations, then ‘finding relations’ in the past becomes a self-fulfilling prophecy. Focusing primarily on the interpretive approaches of material culture studies, this article proposes to counter the threat of irrelevance by not just tracing human-thing relations, but characterising how sets of relations were ordered. Such ordered sets are termed ‘relational constellations’. The article describes three relational constellations and their consequences based on practices of fine ware production in the Western Roman provinces (first century BC – third century AD): the fluid, the categorical, and the rooted constellation. Specifying relational constellations allows reconnecting material culture to specific historical trajectories, and offers scope for meaningful cross-cultural comparisons. As such a small theoretical addition based on the existing toolbox of practice-based approaches and relational thought can impact on historical narratives, and can save relational frameworks from the danger of triviality.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s10816-015-9244-

Forging networks and mixing ores: rethinking the social landscapes of iron metallurgy

This research explores the networks of technological knowledge that influenced changes in the iron production practices of western Uganda in the second half of the second millennium AD. Temporal and spatial variability in technological processes were observed within the research area, in terms of the style and construction of the furnaces, the use of a manganese-rich flux, and the configuration of tuyères. These shifts were considered in relation to the social dimensions of iron production, specifically the protection of technical knowledge. Informed by ethnographic data from the study area, variations were noted in the participation in, or exclusion from, iron production activity on the basis of gender and clan affiliation. This stands in contrast to ethno-historic accounts that speak of a strongly regulated production environment. This paper considers that an uncritical emphasis on conservatism provides an inadequate framework for addressing long-term change in iron production technologies. It suggests that constellations of knowledge in western Uganda fostered the potential for innovation and experimentation, resulting in dynamic technological practice. This paper urges a more nuanced discussion of how complex metallurgical technologies transform and move within cultural and physical landscapes, with ramifications for how we conceptualize the emergence and adoption of early technologies